Asthma Module

Cite this article as:
Miriam Saey Al-Rifai. Asthma Module, Don't Forget the Bubbles, 2020. Available at:
AuthorMiriam Saey Al-Rifai
DurationUp to 2 hours
Equipment requiredNone
  • Basics (10 mins)
  • Main session: (2 x 15 minute) case discussions covering the key points and evidence
  • Advanced session: (2 x 20 minutes) case discussions covering grey areas, diagnostic dilemmas; advanced management and escalation
  • Sim scenario (30-60 mins)
  • Quiz (10 mins)
  • Infographic sharing (5 mins): 5 take home learning points

We also recommend printing/sharing a copy of your local guideline.

Joseph, a 10 year old boy comes into the ED. He is a known asthmatic on treatment. He appears breathless with an audible wheeze. He is able to talk in complete sentences. He has a RR of 25, sats of 94%, pulse of 100 and his PEF is 60% of normal.

What is the severity score of this child’s asthma presentation?

What investigations and treatment options should you consider?

How do you decide when it is safe to discharge home?

The boy is 3 years old with the same presentation – his mum asks you if her son has asthma. What is your response?

When seeing a child with an acute asthma attack, the initial assessment is key to establishing the severity of the attack as this influences ongoing management. 

The following clinical signs should be recorded:

Pulse rate – Increasing tachycardia generally denotes worsening asthma; severe airway obstruction can result in pulsus paradoxus and a fall in heart rate in life-threatening asthma is a preterminal event.

Respiratory rate and degree of breathlessness –  Ie too breathless to complete sentences in one breath or to feed.

Use of accessory muscles of respiration – subcostal, intercostal recessions, tracheal tug. You can also assess by palpation of neck muscles. Also consider including a prolonged expiratory phase.

Amount of wheezing – which might become biphasic or less apparent with increasing  airways obstruction. Silent chest is an indicator of life threatening asthma. It is important to auscultate and document any improvement with treatment.

Degree of agitation and conscious level – always give calm reassurance.


  • Include general observations.


  • NOT routinely advised. A chest X-ray should be performed if there are persisting unilateral signs suggesting pneumothorax, inhaled foreign body, lobar collapse or consolidation and/or life-threatening asthma not responding to treatment.

Blood Gas

  • Only indicated if not responding to treatment or needing further escalation of care


  • If any life threatening features or sats <94%. Aim for sats 94-98%

Inhaled β2 agonist 

  • Salbutamol up to 10 puffs via spacer (1 puff = 5 breaths) assess after 15 mins and repeat if necessary. If sats <94% use,or patient refusal/poor inhaler technique use salbutamol nebulisers (2.5 – 5mg).
  • Continuous nebulisation may be better, as intermittent may result in rebound bronchoconstriction. 

Ipratropium Bromide 

  • If symptoms are refractory to initial β2 agonist treatment, add ipratropium bromide (250 micrograms/dose mixed with the nebulised β2 agonist solution) every 20-30 mins for the first two hours in severe asthma attacks. This should then be tapered to 4-6hrly before being discontinued. However, there are no clinical trials supporting ipratropium use beyond the first hour or first 3 doses in children (EMCases).
  • In a systematic review and meta-analysis comparing the use of beta-agonists plus anticholinergics with beta-agonists alone, combination therapy was associated with significantly lower hospitalisation rates and improvements in asthma scores and pulmonary function test results (EMCases).

Oral steroids 

  • Give oral steroids in the management of acute asthma attacks. Dexamethasone is starting to be used more, as a once only dose, but there is no evidence for benefit over Prednisolone, so not recommended yet. 

Nebulised Magnesium 

  • Nebulised magnesium sulphate is not recommended for children with mild to moderate asthma attacks. The RCT entitled MAGNETIC trial in 2013 of about 500 children showed that MgSO4 nebulisers added to the salbutamol and ipratropium bromide nebuliser in the first hour, for kids with acute severe asthma, significantly improved asthma severity scores without any increase in adverse events.


  • Insufficient evidence to refute or recommend.

Burst therapy – improves forced expiratory volume with an earlier peak response, and prevents deterioration between doses. Salbutamol 100 mcgs x 10 puffs via inhaler & spacer every 20 mins for 1 hour. Add ipratropium bromide 20 mcgs (x 4 puffs < 5 years, x 8 puffs > 5 years) together with salbutamol as above for severe cases.

BTS/SIGN – Children can be discharged home once requiring no more than 3-4 hourly inhalers (based on a randomised controlled study in 1999), PEF >75% and sats >94% . 

Safe follow up

  • Reducing regime of salbutamol inhaler therapy with a clear plan as to when to come back to hospital (ie. requiring >10 puffs in 4 hours)
  • Ensure good inhaler technique/correct fitting spacer mask. Advise to use the B-agonist BEFORE the inhaled steroid and to wash the mouth out after the steroid inhaler to prevent thrush.
  • If the parent/carer of the child smokes, advise them to stop.
  • Address potentially preventable contributors to the exacerbation, such as exposure to trigger factors
  • Ensure the patient is discharged home with 3-5 days oral steroids. Some trusts are now given single dose Dexamethasone, although prednisolone is still in the national guideline ( 
  • Primary care follow-up in 24-48hrs
  • If second attack in 12 months refer to a secondary care asthma clinic.

Wheeze is a common presentation in the ED and its diagnoses and management differs depending on the age of the child and the detail in the history (Snelson et al, 2019). 

An age based approach to wheeze in children


  • Slow onset of symptoms. 3-4 day period of worsening cough, poor feeding, wheeze and respiratory distress due to inflammation of the airways.

Viral Wheeze

  • Rapid onset of wheeze and respiratory distress over hours due to bronchospasm.


  • Described above. 

The age based approach to wheeze can be explained by the changes in a child’s immune system:

  • At birth and in the first few months, immunity is largely provided by maternal antibodies. These antibodies offer protection from most simple viral infections. Acute atopic IgE mediated reactions are very rare. If infections do occur it is likely to be serious bacterial infections. In addition the baby’s own immune system is not yet fully turned on and the response to infection is therefore muted, making the recognition of sepsis difficult in this age group.
  • Preschool age children no longer rely on maternal antibodies. However, their own immune system is still not fully developed. They compensate for this by having heightened and indiscriminate responses to infections. They produce lots of white blood cells, but do not yet have circulating antibodies. You are more likely to see associated problems of viral infections in this age group like transient synovitis. Atopy is becoming more common now. Sepsis is also difficult to recognize in this age group due to the extreme reaction to often uncomplicated viral infections. These children present with viral wheeze. It is worth knowing that there are wheezy presentations in this age group that can look a lot like viral wheeze.  These include bronchomalacia, acute allergy, and cardiac failure due to e.g. acute myocarditis.
  • Older children have a more mature immune system and response to infection is like that of an adult. As the response to infection is less vigorous and indiscriminate than the pre-schoolers, some specific infections like Varicella can cause severe reactions in these children. These children are more likely to have asthma. True asthma is rarely seen under the age of 5 as it requires a fully matured immune system to develop.


  • By looking at the history we can direct our inhaled beta agonist treatment to one that matches a story consistent with bronchospasm. This would include children with likely viral wheeze and asthma.  
  • The best evidence for the use of oral steroids for viral wheeze between the ages of 1 and 5 would suggest that the following group are most likely to have a small benefit (
  • Children with a diagnosis of asthma
  • Children who have required substantial amounts of inhaled beta-agonist prior to presentation
  • Children whose severity and lack of response to treatment with beta-agonists requires admission to hospital
  • Joseph has presented with features of a moderate asthma attack
  • This can be managed with beta 2 agonist therapy and oral steroids
  • Once Joseph does not need beta 2 agonist bronchodilation for more than 4hrs and obs remain stable he can be safely discharged home with safe follow up.
  • The 3 year old presenting with the same symptoms of sudden onset wheeze and breathlessness, likely has a diagnosis of viral wheeze. They would benefit from beta 2 agonist bronchodilation. They are too young to be diagnosed with asthma, but risk factors for developing asthma could be explored in the history.

Leila, a 13 year old female, known asthmatic on treatment, presented to ED breathless and finding it hard to speak in full sentences. Her oxygen saturations are 92%, HR 130 and RR 35

What is the severity score of this child’s asthma presentation?

What investigations and treatment options should you consider?

When do you need to re-assess response to treatment to decide on discharge vs escalation?

  • In this instance, Leila falls into the acute severe asthma presentation. 
  • As her sats <94% oxygen needs to be given via a facemask. 
  • Beta 2 agonist bronchodilator via a nebuliser (preferably oxygen driven) to be given due to sats <94% and she falls into the severe category. 
  • Oral steroids must be given. This can be given as IV Dexamethasone if too unwell/vomiting.
  • Re-assess response to treatment after 15 minutes. 
  • If no improvement after 15 minutes give a further two beta 2 agonist nebulisers and add Ipratropium Bromide nebuliser. 
  • A consideration of nebulised Mg can be given in acute severe asthma.
  • Plan for admission, escalate and refer to paediatrics for consideration of second line treatment.

Do you know how to use a spacer?

Leila has not improved despite the treatment given in ED as outlined in case 2. Her sats are now 89%, she appears cyanosed and has a poor respiratory effort. On auscultation her chest is quiet. What are the next steps that need to be taken?

How would you rate the severity score of this presentation?

What investigations or treatment needs to be considered?

Which IV medications if any should be used? 

Which important differentials need to be considered?

What escalation plans need to be put in place?

Children with continuing severe asthma despite optimal first-line treatments, frequent nebulised β2 agonists and ipratropium bromide plus oral steroids, and those with life-threatening features, need urgent review by a specialist with a view to management in an appropriate high-dependency area or transfer to a paediatric intensive care unit to receive second-line intravenous therapies. It is important to do a blood gas prior to starting bronchodilators to measure the pCO2 and also to monitor side effects of salbutamol (decreasing potassium and lactic acidosis).

PERUKI (Paediatric Emergency Research in the UK and Ireland network) is a research collaborative of paediatric-specific and mixed adult and paediatric emergency departments (EDs). In 2015 PERUKI carried out a study looking at the variation in practise of the use of IV bronchodilators as a second line treatment in the management of acute asthma in children. There was a large discrepancy between what clinicians felt was the appropriate management and what they actually administered. A survey of 183 clinicians in 30 EDs revealed that when escalating to intravenous bronchodilators, 99 (54%) preferred salbutamol first line, 52 (28%) magnesium sulfate (MgSO4) and 27 (15%) aminophylline. 87 (48%) administered intravenous bronchodilators sequentially and 30 (16%) concurrently, with others basing approach on case severity. 146 (80%) continued inhaled therapy after commencing intravenous bronchodilators. 

Of 170 who used intravenous salbutamol, 146 (86%) gave rapid boluses, 21 (12%) a longer loading dose and 164 (97%) an ongoing infusion, each with a range of doses and durations. Of 173 who used intravenous MgSO4, all used a bolus only. What this demonstrates is the considerable variability in practise and opinion. 

So what is the evidence? (Cochrane review)

IV salbutamol 

  • There have not been enough trials to form a robust evaluation of its benefits.


  • Appears to be safe and beneficial in severe asthma

IV aminophylline 

  • Improves lung function within 6hrs. However, there is no apparent reduction in symptoms, number of nebulised treatments or length of hospital stay. We do not know the impact on oxygenation, PICU admissions or need for NIV. 

IV ketamine 

  • There has only been 1 study conducted, which reveals no known benefit in non intubated children. 

In one RCT comparing IV aminophylline, salbutamol and magnesium in 100 children, a bolus of magnesium sulphate was shown to reduce clinical symptoms faster than the other treatments. There were no significant side effects documented in the magnesium sulphate group. A systematic review of four paediatric trials comparing IV salbutamol with IV aminophylline demonstrated equivalence.

In children who respond poorly to first-line treatments, consider the addition of intravenous magnesium sulphate as first-line intravenous treatment (40 mg/kg/day).

Consider early addition of a single bolus dose of intravenous salbutamol (15 micrograms/kg over 10 minutes) in a severe asthma attack where the child has not responded to initial inhaled therapy. It is not clear whether IV bolus vs infusion is more beneficial. Prior to IV salbutamol administration insure blood potassium is checked and on cardiac monitor. If using an IV infusion monitor lactate to check for toxicity. 

Consider aminophylline for children with severe or life-threatening asthma unresponsive to maximal doses of bronchodilators and steroids. Some of the side effects include abdominal pain, anxiety, headache, nausea, palpitations and seizures. Toxicity can occur with aminophylline. This presents as vomiting (which may be severe and intractable), agitation, restlessness, dilated pupils, sinus tachycardia, and hyperglycaemia. More serious effects are haematemesis, convulsions, and supraventricular and ventricular arrhythmias. Severe hypokalaemia may develop rapidly especially in combination with salbutamol.

Ensuring you have appropriately assessed and optimised their condition

Reassess the patient?

  • Consider revisiting history, respiratory examination and consider adjuncts to assessment such as a capillary or venous blood gas.

Have you exhausted medical management?

  • ? adrenaline ? ketamine ?heliox 

What could be missing? 

  • Consider your confidence of whether you have the right diagnosis or if there is a need to assess for a secondary pathology such as pneumonia, foreign body, anatomic airway anomalies, airway compression by masses/lymph nodes, cardiac disease? Some can be excluded with a good history. Do you need to further investigate with bloods, CXR? Do you need to append your management and provide antibiotic coverage? Do you need to assess for a complication from treatment e.g. pneumothorax.

Escalation options

  • Have you sought a senior review/notified the admitting paediatrician?
  • Do you need an ICU consult, NETS consult or retrieval to a tertiary centre?
  • How long are you comfortable to wait to see if there is a response to IV bronchodilation?

Non invasive ventilation 

  • Is there any evidence in acute asthma attack?
  • What settings/mode would you use?

Does this child need to be intubated?

  • How would you determine this?
  • Who should be involved in the conversation? Who should perform the intubation?
  • What sedation would you use?
  • What equipment would you use?
  • What settings would you use?

Alternative treatment options


Give for severe or life threatening asthma – if the diagnosis is in doubt. 

Asthma and atopy often co-exist – and in these patients death from anaphylaxis is more likely. So if a patient fails to respond to initial therapy, the diagnosis of anaphylaxis needs to be considered. In addition nebulised Adrenaline causes bronchodilation.  


May improve respiratory score, but it probably won’t reduce the risk of admission. Nor should you use it in routine asthma to stave off intubation (PEMBlog). Can be considered in the ICU setting with maximum oxygen therapy has failed. 


Limited number of trials with mixed outcomes on the benefits of Ketamine. However, it is safe at dissociative dosages, and is a reasonable option when all others measures have failed.


A few case reports and observational studies of the use of BiPAP in pediatric asthma show some promise. The one RCT of only 20 patients does show a benefit in clinical asthma scores, respiratory rate, and supplemental oxygen need. There is no evidence that it prevents the need for intubation (Basnet S et al, 2012).

Critical care input is the next step for children with severe asthma not responding to treatment or with any life threatening features. There are a number of ongoing trials on the use of ketamine, sevofluorane and NIV, but the evidence is currently lacking so they’re not recommended by BTS/SIGN.

A 15 year old male has been brought into resus with features of life threatening asthma. Pre hospital the paramedics gave continuous salbutamol nebulisers, 500mcg Ipratropium nebulisers and 0.5mg IM Adrenaline. The attending medical team in resus administered 2g IV Mg over 20 mins and a bolus of 250mcg IV Salbutamol. The patient then became unresponsive with no respiratory effort.

What are the next steps that need to be taken?

What is the ‘deadly triad’ in asthma?

What are the key ALS modifications in asthma arrest?

In the pre-hospital setting, paramedics usually give IM Adrenaline to cover for the possibility of a diagnosis of anaphylaxis. 

In this case the patient has arrested. As soon as this has been identified, CPR needs to be initiated as per the ALS guidelines.

The cause of cardiac arrest in asthma is a result of the ‘deadly triad’:

Important modifications and considerations in managing cardio respiratory arrest in asthma (RCEMLearning –

  1. Intubate Early

Due to the need for high inflation pressures, an endotracheal tube (ETT) is needed. In addition this protects the airway from the increased risk of regurgitation and aspiration.

  1. Ventilate with caution

The European Resuscitation Council recommends 8-10 breaths per minute with the lowest tidal volume required to see the rise and fall of the chest, to avoid dynamic hyperinflation. Tachypnoea must be avoided as this reducses expiratory time, thus increasing the residual volume in the alveoli. This auto PEEP increases intrathoracic pressure which reduces venous return, impeding CPR. 

  1. Manual chest deflation

If the patient has a hyperinflated chest/poor excursions of the chest wall, disconnect the ETT and apply manual pressure to the patient’s chest to expel the trapped air. 

  1. Consider tension pneumothorax

If ETT disconnection does not improve ventilation, consider performing a bilateral thoracostomy.

  1. Rehydrate

Dehydration and reduced intravascular volume compromises effective CPR. It also causes mucus to be thicker which can plug small airways. So ensure you give IV fluids. 

  1. GIVE ADRENALINE! – Utilise its bronchodilator effect. 

In an acute asthma exacerbation in children, monitoring the oxygen sats is important because:

A: Hypoxaemia is an early sign of clinical deterioration 

B: Sats <95% may suggest the need for prolonged bronchodilator therapy

C: Hypoxaemia occurs in the presence of life threatening asthma. Children may have normal sats for some time before critical desaturation occurs.

D: Sats >96% supports the decision to safely discharge home

The correct answer is C.

In an acute asthma attack hypoxic vasoconstriction occurs. This is coupled with decreased blood flow to the under ventilated lung (matching pulmonary perfusion with alveolar ventilation). 

In the hospital setting SaO2<91% may be a helpful predictor of prolonged frequent bronchodilator therapy more than 4 hours and SaO2 of <89% is associated with a need for bronchodilator therapy over 12 hours.

Hypoxaemia and hypocarbia only occur in the presence of life threatening asthma. Children may have normal sats for some time before critical desaturation occurs. Whilst low oxygen saturations mean that a patient is unwell it should be clinically obvious at this point.  Low oxygen saturations may also represent a degree of mucus plugging that may be helped with repositioning.

Hyperoxia can lead to absorption atelectasis as well as intra-pulmonary shunting with subsequent reduction in cardiac output. In addition concerns have been raised that oxygen administration may lead to potential delay in recognising clinical deterioration.

What is an appropriate length of time to stretch children in the ED prior to discharge?

A: After two sets of 3-4hrly inhaler/nebulisers

B: After they reach the first 3-4 hrs post last inhaler/nebuliser

C: After two sets of 3hrly

D: After 1 hour, if obs are completely normal and has had a consultant review

The correct answer is B.

BUT this is based on a randomised control trial in 1999. The most recent study in 2018 suggests that there is no benefit to 4hours vs 3hrs, and in fact 3 hrs post inhalation resulted in a reduction in length of stay. A recent retrospective analysis study in Australia looked at discharging children after 1 hour. They suggested that children that were clinically ‘well’ at 1 hour were likely to go home and if they were showing any moderate symptoms at one hour would likely need to be admitted. There is no strong evidence or recent studies, which is why there is such variation in practice. 

Under what circumstances would you choose to administer a beta agonist via nebuliser as opposed to a pMDI with a spacer?

A: When the child has become more tachycardic with worsening salbutamol induced tremor

B: In severe or life threatening asthma or when under the age of 1yrs old/learning difficulties

C: If the pMDI is ineffective

D: Some departments prefer nebulisers as it is cheaper than inhaled preparations

The correct answer is B.

Cochrane review 2013 – “Metered-dose inhalers with a spacer can perform at least as well as nebulisation in delivering beta-agonists in children with acute asthma”

Salbutamol has systemic side effects – tremor and increased pulse rate were more common when using nebulisers. SIGN/BTS guidelines state to give nebulisers in severe or life threatening asthma. Nebulisers are also preferential in very young children, or those with learning difficulties, as coordinating breathing with an inhaler can be difficult. Cost savings can be made with inhaled preparations. 

When is intubation indicated in paediatric asthma presentations?

A: When the HR > 160 OR the RR > 60

B: When you have given all first line and second line treatment and trialled NIPPV and the patient has still not improved. 

C: The child looks exhausted with worsening hypercapnia and changes in mental status. 

D: When the child has a history of fast deterioration and need for intubation

The correct answer is C.

Up to 26% of children intubated due to asthma suffer complications including pneumothorax, impaired venous return, and cardiovascular collapse because of increased intrathoracic pressure. Mechanical ventilation during an asthma exacerbation is associated with an increased risk of death and should therefore be a last resort. The decision to intubate should be based on clinical judgement as opposed to any one observation or blood result. Some variables to consider for intubation are worsening hypercapnia, patient exhaustion and changes in mental status (EMCases).

You have a 4 yr old, with two days of wheeze, coryzal symptoms and one day of increased work of breathing symptoms. You suspect that this may be viral induced wheeze. How do you manage this child?

A: Burst therapy with salbutamol. 

B: 6-10 puffs of salbutamol and reassess. If severe symptoms give oral steroids. 

C: Humidified air nebuliser and antipyretics for fever. 

D: 6-10 puffs of salbutamol and Ipratropium bromide nebuliser. If severe symptoms give oral steroids.

The correct answer is B.

At what age would it be appropriate to consider a trial of ventolin for potential viral induced wheeze? 

  • (Note – This is a good opportunity to survey your team and colleagues to see what the practice is at your local department). 
  • Regarding this grey area question, in Australian practice, some clinicians will trial salbutamol for potential viral induced wheeze if the child is 12 months or older. Other doctors may wish to trial if the child is slightly younger (e.g. from 10 months) if they have a strong family history of asthma and atopy or if they have had previous ventolin use reported by their family with good effect. The younger the child is, the less likely that the story and case is to fit viral induced wheeze.

If you are not sure if the child is presenting with asthma or viral induced wheeze, but they are displaying severe symptoms – it is advisable to give steroids. But be cautious in giving too many courses of steroids if presenting frequently to the ED.

M Balfour-Lynn (1996) Why do viruses make infants wheeze?, Archives of Disease in Childhood  74: 251-259

MO Stormon, CM Mellis, PP Van Asperen, HA Kilham (2002) Outcome evaluation of early discharge of asthmatic children from hospital: A randomized control trial, Journal of quality in clinical practise, Vol 19, issue 3, 149-154

Huay-ying Lo, Amanda Messer, Jennifer Loveless, Esther Sampayo, Robert H. Moore, Elizabeth A. Camp, Charles G. Macias and Ricardo Quinonez (2018) Discharging Asthma Patients on 3-Hour β-Agonist Treatments: A Quality Improvement Project, Hospital Pediatrics, 8 (12) 733-739

Basnet S, Mander G, Andoh J, Klaska H, Verhulst S, Koirala J (2012) Safety, efficacy, and tolerability of early initiation of noninvasive positive pressure ventilation in pediatric patients admitted with status asthmaticus: a pilot study. Pediatr Crit Care Med 13(4):393-8.

Snelson, E (2019) A simple model for understanding the causes of paediatric wheeze, Paediatrics and Child Health, Volume 29, Issue 8, Pages 365-368

DFTB – Managing acute asthma, Simon Craig (2017)

DFTB – Asthma for ambos (2016)

DFTB – Are nebulisers or spacers better for managing acute asthma (2013)

DFTB – The curious incident of the wheeze in the night

PEMBLOG – Heliox in the emergency department (2017)

EMCases – Management of acute paediatric exacerbations (2016)

BTS/SIGN British guideline on the management of asthma in children (2019)

PaediatricFOAM – ventilation strategies for the critically ill asthmatic (2019)

RCEMLearning – Arrest in asthma – The NYCE guideline for viral induced wheeze – Let’s clear a few things up (2019)

Please download our Facilitator and Learner guides

Inherited Metabolic Disorders Module

Cite this article as:
Taciane Alegra. Inherited Metabolic Disorders Module, Don't Forget the Bubbles, 2020. Available at:
TopicInherited metabolic disorders
AuthorTaciane Alegra
Duration1 to 2 hours
Equipment requiredNone
  • Basics (10 mins)
  • Main session: (5 x 20 minute) case discussions covering the key points and evidence
  • Quiz (10 mins)
  • Infographic sharing (5 mins): 5 take home learning points

We also recommend printing/sharing a copy of your local guideline.

This module presents an approach to acute metabolic presentations, how to identify potential problems and emergency treatment in the ED. You don’t need to make a diagnosis (bonus points if you do) but do need to remember that spotting the zebra will lead to more favourable outcomes. Metabolic diseases / disorders are also called inborn errors of metabolism (IEM).

How common are they?

Individually, metabolic conditions are rare, most having an incidence of less than 1 per 100,000 births. However, when considered collectively, the incidence may reach 1 in 800 to 1 in 2500 births (Applegarth et. al, 2000; Sanderson, 2006). 

Remember: some symptoms can be unspecific and can mimic sepsis; or a child with an undiagnosed metabolic condition can decompensate with an intercurrent infection. 

An easy-to-understand classification by Saudubray divides the IEM in three groups of disorders, depending on how they present. 

An acute or progressive intoxication from the accumulation of toxic compounds, usually small molecules. 

These usually present with a symptom-free interval and clinical signs of ‘intoxication’, which may be acute, although can be intermittent.

  • disorders of amino acid catabolism: e.g. phenylketonuria, maple syrup urine disease, homocystinuria, tyrosinemia 
  • most organic acidurias: e.g. methylmalonic, propionic, isovaleric acidaemia
  • urea cycle defects: e.g. Ornithine transcarbamylase deficiency (OTC deficiency), Citrullinemia type I (ASS1 deficiency).
  • sugar intolerances: galactosemia
  • metals: Wilson’s, Menkes, hemochromatosis
  • Porphyrias.

A deficiency in energy production or utilization, within the liver, myocardium, muscle, brain or other tissues. 

Common symptoms include hypoglycemia, hyperlactatemia, hepatomegaly, failure to thrive and cardiac failure. 

  • Mitochondrial defects: congenital lactic acidemias (defects of pyruvate transporter, pyruvate carboxylase, pyruvate dehydrogenase, and the Krebs cycle), mitochondrial respiratory chain disorders and the fatty acid oxidation defects (MCAD deficiency).
  • Cytoplasmic energy defects: disorders of glycogen metabolism (collectively known as glycogen storage diseases), hyperinsulinism.  

Problems in the synthesis or catabolism of complex molecules, leading to storage of big molecules. 

Symptoms are chronic, progressive and independent of intercurrent events or food intake. 

  • Mucopolysaccharidosis (I-IV, VI and VII). The eponymous names are used less frequently now, particularly in the literature, but you might come across them in clinical practice (MPS I, Hurler’s Syndrome; MPS II, Hunter’s Syndrome; MPS VI, Maroteaux- Lamy) 
  • Gaucher disease
  • Peroxisomal disorders: e.g. X-linked adrenoleukodystrophy (X-ALD) and Zellweger’s Syndrome.

Remember your biochemistry: a substrate is transformed by an enzyme into a product.

If there is a problem with the enzyme, there will be more substrate. If accumulation of the substrate is the problem, we remove it (like avoiding protein in the diet).  Or, if the problem is the lack of the product, we can supplement it. And for some diseases the  enzyme can be “corrected” (by organ transplantation, enzyme replacement).

Due to accumulation of “unusual” products in their body fluids, people with certain metabolic conditions have distinctive odours (better observed in urine, for practical reasons):

  • Maple syrup, burnt sugar, curry: Maple syrup urine disease
  • Sweaty feet: glutaric aciduria type II, isovaleric acidaemia
  • Cabbage: tyrosinemia
  • Mousy, musty: Phenylketonuria
  • Rotting fish: Trimethylaminuria
  • Swimming pool: Hawkinsinuria 

It’s early morning in the ED and you are enjoying your coffee. You’re called in to see a neonate with a history of irritability and seizures. You enter the room and are told the following: “Emma is a 3 day old, term baby who has been refusing feeds and crying excessively. There has been no history of fever or cough. At home she had seizure-like activity with tonic posturing”. 

First pregnancy, no antenatal or perinatal problems. Birth: Weight: 2950g,  Apgar 9/10. Discharged home on day 2. Irritability since birth. Vomiting after feeds (mixed: breast and formula). 

Examination: Awake, extremely irritable, upper limbs flexed, lower limbs extended, global hyperreflexia. No dysmorphic features. Otherwise no positive findings. Weight: 3050g

Vitals: Temp 36.8ºC, HR 155, RR 48, O2 sats 99%, BP wasn’t checked.

What are the red flags in Emma’s story?

What tests do you want to send?

  • Irritability and excessive crying
  • Acute onset of seizures, without any obvious trigger. 
  • Blood gas, glucose, U&E, LFTs, CRP, blood culture, urine ketones and MC&S, metabolic screen. Consider CT brain.

FBC, CRP, U&E, LFTs  – normal

Venous blood gas:

  • pH: 7.33 
  • pCO2: 3.1 kPa*
  • HCO3: 14 mmol/L
  • Na+: 142 mmol/L
  • K+: 4 mmol/L
  • Chloride: 100 mmol/L

Glucose: 5 mmol/L

Ketones: 2.1mmol/L

Ammonia 184

Urine: Ketones +2, and smells of sweaty feet.

Metabolic screen: plasma amino acids, urine organic acids, acylcarnitine profile sent 

*1kPa = 7.5mmHg

This baby has an acute neurological presentation, with metabolic acidosis, increased anion gap and mildly elevated ammonia –  suggestive of an organic acidemia

  • A normal ammonia level is <50 mol/l but mildly raised values are common, up to 80 mol/l. 
  • Artifactually high values can be caused by muscle activity, haemolysis or delay in separating the sample. Capillary samples are often haemolysed or contaminated and therefore should not be used. 
  • In neonates, any illness may be responsible for values up to 180 mol/l. 
  • There’s debate as to whether a level of >100 or 200 should be discussed with a metabolic specialist, but if in doubt, follow the RCPCH DeCon guideline and seek advice for any patient presenting with a level >100.
  • The AG is raised at 32mEq/L [(Na + K) – (Cl + HCO3)]. 
  • (142 + 4) – (100 + 14) = 146 – 114 = 32
  • PEMinfographics have a nice infographic explaining interpretation of anion gaps in children. In the context of a sick neonate with a raised AG, a normal lactate and normal ketones, think organic acids.
  • Urine organic acids and blood acylcarnitines will also be sent as part of this baby’s metabolic work-up. Although the results won’t be available to us in ED, the urine organic acid profile will confirm a diagnosis of an organic acidaemia, while the blood acylcarnitine profile will support the diagnosis as the organic acids conjugate with carnitines creating compounds such as isovalerylcarnitine.
  • It’s important to think about your differentials. Sepsis is the most common – these conditions can mimic sepsis, or decompensation can be triggered by an infection, always cover with broad spectrum antibiotics. But don’t forget non-accidental injury and other differentials – the baby is likely to need a CT head if presenting encephalopathic or with seizures.
  • Manage seizures in the usual way. 
  • Specific emergency treatment of her metabolic presentation requires 
  • stopping sources of protein (milk)
  • avoiding catabolism (by giving glucose IV – 2mL/kg 10% glucose) 
  • rehydration (IV fluids resuscitation and maintenance)
  • The “sweaty feet” smell is a clue to the diagnosis of Isovaleric Acidaemia. Remember that this condition can be part of the Newborn Screening in some countries (Ireland, UK, Australia, New Zealand).
  • Isovaleric acidaemia is a type of organic acidemia, inherited in an autosomal recessive way. It is caused by a problem with the enzyme that usually breaks down the amino acid leucine. This amino acid accumulates and is toxic at high levels, causing an ‘intoxication’ encephalopathy. The sweaty feet smell is stronger without treatment or  during acute exacerbations. 
  • Maple Syrup Urine Disease (MSUD) is another organic acidaemia, associated with sweet smelling urine during decompensation. These children cannot break down leucine, valine and isoleucine. They may not have hypoglycaemia, hyperammonemia or acidosis and, if not picked up on newborn screening, can be diagnosed late, resulting in neurological sequelae.
  • Sick neonates with metabolic acidosis, increased anion gap and mildly elevated ammonia may have an organic acidemia.
  • Treatment is to stop feeds, prevent catabolism with 10% dextrose (and standard electrolytes for IV maintenance) and cover for sepsis with IV antibiotics, whilst considering other differentials.

The next baby you see is remarkably like Emma but with a subtle difference.

Lucy is a 3 day old baby, presenting with poor feeding, irritability and seizures at home. There has been no fever, cough, coryza, or sick contacts. 

Examination:  Awake, extremely irritable, upper limbs flexed, lower limbs extended, global hyperreflexia. No dysmorphic features . You notice that she seems tachypnoeic, although lungs are clear. 

Vitals: Temp 36.8ºC, HR 155, RR, O2 sats 98%, BP wasn’t checked. 

Glucose = 5 mmol/L Ketones = 0.1 mmol/L

VBG: respiratory alkalosis 

Venous blood gas:

  • pH: 7.48
  • pCO2: 3.1 kPa*
  • HCO3: 24 mmol/L
  • Na+: 135 mmol/L
  • K+: 4 mmol/L
  • Chloride: 99 mmol/L

*1kPa = 7.5mmHg

What are the key differences between Lucy’s and Emma’s presentations?

What is the anion gap? 

What does a respiratory alkalosis make you suspicious of?

  • Lucy is tachypnoeic and has a respiratory alkalosis
  • Emma, on the other hand, had a metabolic acidosis with a normal respiratory rate
  • AG = 16 mEq/L
  • (Na + K) – (HCO3 + Cl) = (135 + 4) – (99 + 24) = 139 – 123 = 16
  • Unlike Lucy’s case, this baby has a normal anion gap.


The lab phones you with Lucy’s ammonia result. It’s 1250.

  • This baby have a neurological acute presentation, with respiratory alkalosis and extremely elevated ammonia –  suggestive of a urea cycle disorder
  • High ammonia stimulates the brain stem respiratory centre, causing hyperventilation and, as consequence, respiratory alkalosis 
  • Overall treatment is similar to case 1: cover for sepsis, manage seizures and consider differentials. 
  • As with organic acidaemias, the initial (specific) treatment requires 
  • stopping sources of protein (milk)
  • avoiding catabolism (by giving glucose IV – 2mL/kg 10% glucose) 
  • rehydration (IV fluids resuscitation and maintenance).
  • In urea cycle disorders, the toxic metabolite is ammonia, so ammonia scavengers are used, all given intravenously:
  • sodium benzoate
  • phenylbutyrate 
  • arginine
  • Urea cycle disorders are autosomal recessive inborn errors of metabolism. A defect in one of the enzymes of the urea cycle, which is responsible for the metabolism of nitrogen waste from the breakdown of proteins, leads to an accumulation of ammonia as it cannot be metabolised to urea. The urea cycle is also the only endogenous source of the amino acids arginine, ornithine and citrulline. 
  • The most common urea cycle disorder is OTC deficiency. Unlike the other urea cycle disorders (which are autosomal recessive), OTC deficiency is x-linked recessive, meaning most cases occur in male infants. Female carriers tend to be asymptomatic.
  • Classically, urea cycle disorders present in the neonatal period with vomiting, anorexia and lethargy that rapidly progresses to encephalopathy, coma and death if untreated. In these circumstances, ammonia accumulates leading to a very high plasma ammonia. 
  • Respiratory alkalosis is a common early finding caused by hyperventilation secondary to the effect of hyperammonemia on the brain stem, although later the respiratory rate slows as cerebral oedema develops and an acidosis is seen.
  • Children presenting in infancy generally have less acute and more variable symptoms than in the neonatal period and include anorexia, lethargy, vomiting and failure to thrive, with poor developmental progress. Irritability and behavioural problems are also common. The liver is often enlarged but, as the symptoms are rarely specific, the illness is initially attributed to many different causes that include gastrointestinal disorders. The correct diagnosis is often only established when the patient develops a more obvious encephalopathy with changes in consciousness level and neurological signs. 
  • Adolescents and adults can present with encephalopathy and or chronic neurological signs. 

Ammonia scavengers

  • In urea cycle defects, ammonia cannot be converted to urea so instead is converted to glutamine and glycine. 
  • Ammonia scavengers phenylbutyrate and sodium benzoate can be given – they offer alternative pathways for ammonia excretion through urinary pathways.
  • Phenylglutamine and hippurate are produced and are excreted in urine.
  • Sick neonates with respiratory alkalosis, normal anion gap and very elevated ammonia may have a urea cycle defect. 
  • Emergency treatment is the same as for an organic acidaemia plus ammonia scavengers.

Jane, 14 years old, is brought in by ambulance unconscious after a generalized tonic clonic seizures at home lasting at least 20 minutes. While doing the standard resuscitation steps, you talk to her mother. You learn that she has been a healthy child with no chronic conditions, no history of drug abuse, no acute illness. She’s a vegetarian and enjoys dancing. It’s the Coronavirus pandemic, so she has been at home for the last 3 weeks. She’s started a new ‘intermittent fasting diet’ and yesterday, hadn’t eaten since brunch. She went to bed early and this morning her mother was woken early by strange sounds coming from Jane’s room and found her seizing on the floor. 

Physical exam:  GCS 10/15, hyperreflexia. No dysmorphic features . You notice that she seems tachypneic, although lungs are clear. 

Vitals: Temp 37.4ºC, HR 112, RR 30, O2 sats 100% on supplemental oxygen (started at the ambulance),  BP 110/70 mmHg.

You send some bloods:

Glucose = 5 mmol/L Ketones = 0.1
VBG: respiratory alkalosis 
Ammonia = 650 (normal <40)
Anion gap = 15 (normal)
LFTs: slightly above reference levels
FBC, U/E, CRP  normal

What are your differential diagnoses?

What key points in this case point you towards a metabolic disorder?

  • This adolescent has an acute onset of neurological symptoms. The differential diagnoses are broad but a red flag for a metabolic condition is that her encephalopathy was precipitated by prolonged fasting. 
  • The RCPCH decon guideline lays out an approach to the child with a decreased conscious level, including differentials, investigations and management (take a look at the DeCon poster and summary guidance). 
  • All children presenting with a decreased conscious level, regardless of age, should have an ammonia sent as part of their initial investigation in ED.
  • In late onset urea cycle defects, acute metabolic encephalopathy develops following metabolic stress precipitated by a rapid increase in nitrogen load from
  • infection, trauma, rapid weight loss and auto-catabolism, increase in protein turnover from steroids, surgery, childbirth or other precipitants of protein catabolism.
  • Adolescents and adults with an undiagnosed urea cycle defect may be completely fit and well, but may have chronic symptoms such as headache, cyclical vomiting, behavioural difficulties, psychiatric symptoms or mild learning difficulties.
  • They may be selective vegetarians, restricting their protein intake.
  • Between episodes patients are relatively well. However, acute presentations can be fatal or patients may be left with a neurological deficit, so the learning point is to always send an ammonia in any child presenting with an acute encephalopathy.
  • Two cases reports your team may find interesting

Send ammonia as part of your investigation of adolescents presenting with a decreased conscious level 

It’s 11am on Easter Monday in Dublin. Ellie-Mae is a 6 day old baby, born at 37 weeks via SVD,  in Wales while her mother was visiting some friends. When Ellie-May was 3 days old her mother returned to Ireland to stay with her own mother, for some early baby support. Since day two of life Ellie-Mae has been vomiting after feeding. She is bottle fed and since yesterday she has only been accepting half of each bottle, but mother thought it was tiredness from the long trip.

Ellie-Mae’s mother brought her to the ED this morning because she has been quiet, hasn’t been crying as usual with nappy changes and seemed too sleepy to take this morning’s bottle. 

Pregnancy: Mother 21 years old, G1P1, no problems. 

Birth: SVD at 37/40, BW 2.9kg, no resus, no NICU.She was jaundiced on the second day of life, but below phototherapy levels. 

Family history: healthy parents from the Irish Traveller Community. 

Physical exam: Weight 2.45kg (16% below birth weight), jaundiced, lethargic. Anterior fontanelle is sunken, and Ellie-Mae looks dehydrated. You can palpate the liver 2 cm below the right costal margin. No spleen palpable. Otherwise no positive findings.

Vitals: Temp 37ºC, HR 185, Capillary refill time 3 seconds, RR 55, BP systolic = 102 mmHg (crying), O2 sats 97%

What are the red flags in Ellie-Mae’s case?

  • History: vomiting and lethargy
  • 16% weight loss by day 6 of life
  • Examination: jaundice and a palpable liver

You take some bloods:

Glucose 2.0mmol/L
Ketones = 6 mmol/L
VBG metabolic acidosis – hyperchloremic

Venous blood gas:

  • pH: 7.32
  • pCO2: 4 kPa
  • HCO3: 20 mmol/L
  • Na+: 135 mmol/L
  • K+: 3.5 mmol/L
  • Chloride: 95 mmol/L

When you see Ellie-Mae’s low glucose level you send a hypoglycaemia screen.

You also send FBC, U&E, LFTs, clotting, ammonia and blood culture.

LFTs: AST 70U/L, ALT 75U/L, Bilirubin total 255 µmol/L, direct 60µmol/L,  Alkaline phosphatase  270U/L
INR 1.8
Ammonia 47

How do you investigate hypoglycaemia?

What treatment do you want to start in ED?

Do these tests make you suspicious of any diagnoses?

  • Discuss your institution’s hypoglycaemia guideline – which tests to send, where to find the bottles and Guthrie cards.
  • Hypoglycaemia, this neonate has hepatomegaly and raised liver enzymes point towards a diagnosis of galactosaemia.
  • Some countries screen for galactosaemia in their newborn screening programmes (Ireland, UK, New Zealand, some parts of Australia). Because of its autosomal recessive inheritance, galactosaemia is more common in some ethnic groups. 
  • In the Irish travelling community, for example, the incidence is higher than the rest of the populations, so babies born to parents from the travelling community are specifically screened on day 1 of life in Irish maternity hospitals. The baby’s diet should exclude galactose, so newborn babies of Irish travelling families are given soy-based formula rather than breast feeds or standard formula until their screening test result is known.
  • The initial investigation and management of hypoglycaemia: this baby needs Glucose 10% 2mL/kg IV as soon as possible. Collect blood prior to treatment.
  • Management is similar to the previous cases: 
    • Clinical stabilisation
    • Antibiotics
    • stop feeds
    • Correct hypoglycaemia with 2ml/kg 10% 
    • Give maintenance fluids with electrolytes to maintain hydration as per your local policy

Galactosaemia occurs due to a defect in the enzyme galactose-1-phosphate uridyl transferase (GALT). It presents after the affected patient receives the sugar galactose, present in milk. Accumulation of galactose-1-phosphate results in damage to the brain, liver, and kidney. The affected neonate presents with vomiting, hypoglycaemia due to an inability to metabolise glucose, feeding difficulty, seizures, irritability, jaundice, hepatomegaly, liver failure, cataracts, splenomegaly, and Escherichia coli sepsis. The condition presents with metabolic acidosis. Source: Gene Reviews 

Liz is a 3 year old girl from the countryside, who is visiting her grandmother in the city. She has been having diarrhoea since yesterday and started vomiting last night. In the last 3 hours she hasn’t been able to tolerate anything orally. There has been no fever or respiratory symptoms and she is passing urine as normal. Her 5 years old cousin has similar symptoms. 

Her Grandmother informs you that Liz has MCAD deficiency and her emergency plan was tried at home, without success. Liz is not usually treated at your hospital and you don’t have her chart. Unfortunately Liz’s grandmother didn’t think to bring the plan to hospital. 

Physical exam: Liz looks tired and is mildly dehydrated, but smiles at you. Her heart sounds are normal and her chest is clear. She has increased bowel sounds, a soft abnormal with mild diffuse pain on deep palpation and no masses or organomegaly. 

Vitals: Temp 37ºC, HR 165, capillary  refill time 3 seconds, RR 32, BP systolic = 104mmHg, O2 sats 97% in air.

Glucose 2.5 mmol/L, Ketones 0.4 mmol/L

What is the priority in Liz’s treatment?

Is her ketone response appropriate to the degree of hypoglycaemia? 

Liz’s grandmother told you Liz has MCAD Deficiency, but what is it?

Where can you find resources to help you manage Liz?

Liz has MCADD and needs extra calories when she is sick. The most important intervention is to give simple carbohydrates by mouth (e.g. glucose tablets or sweetened, non-diet beverages) or intravenously if needed to reverse catabolism and sustain anabolism. Liz is vomiting all oral intake so cannot tolerate oral carbohydrates, so the intravenous route is necessary.

No, it’s not. The body’s response to prolonged fasting is to break down fat to create ketones to be used as an alternative source of energy. Liz has not produced ketones, because she is unable to break down fat.

  • Medium-chain acyl-CoA dehydrogenase deficiency (MCADD) is the most common fatty acid oxidation disorder in Caucasians in Northern Europe and the United States. Most children are now diagnosed through newborn screening
  • Children with fatty acid oxidation disorders (medium, long and short chain defects) have typical acylcarnitine patterns. This is one of the reasons acylcarnitines are sent as part of metabolic and hypoglycaemia work-ups. 
  • Clinical symptoms in a previously apparently healthy child with MCAD deficiency include hypoketotic hypoglycemia and vomiting that may progress to lethargy, seizures, and coma, triggered by a common illness. Hepatomegaly and liver disease are often present during an acute episode. 
  • Children appear well at birth and, if not identified through newborn screening, typically present between three and 24 months of age, although presentation even as late as adulthood is possible. 
  • The British Inherited Metabolic Disease Group, BIMDG, has specific guidance on their website, including
    • Correct hypoglycaemia immediately with 200mg/kg glucose: 2 ml/kg of 10% glucose or 1ml/kg of 20% glucose, over a few minutes. 
    • Treat shock or circulatory compromise with a bolus of 20ml/kg 0.9% sodium chloride. 
    • Give maintenance fluids with potassium once the plasma potassium concentration is known and the child is passing urine. 

Mike is 12 years old, presenting to the ED with cough and fever. He has been coughing for 10 days, worse progressively in the last five and febrile in the last 3 days. Since yesterday he just wants to sleep and even when afebrile he looks unwell. Appetite is poor and he has been “sipping some apple juice”. You learn from his mother that he has a condition called Mucopolysaccharidosis (MPS) type I and is on treatment with “the enzyme”. Every now and again, “he is chesty and needs to come to hospital”. 

Physical exam: Pink, hydrated, but looks sick. You notice that he is shorter than an average 12 year old boy, has hand contractures and coarse facial features. 

Cardiovascular: systolic murmur, +2/+6. Good pulse volume. Respiratory: creps and rhonchi on the right side. Abdominal exam: mild hepatomegaly. Umbilical hernia. 

Vitals: Temp 37.5ºC, HR 132, RR 30, BP systolic = 112mmHg, O2  sats 88% in air.

What is Mike’s clinical diagnosis and what treatment do you want to start in the ED?

  • Patients with Mucopolysaccharidosis don’t require any emergency treatment in the ED for their underlying metabolic disease. They are, however, at increased risk of respiratory infections.
  • Mike is likely to have a community acquired pneumonia and needs to be treated accordingly with oxygen and antibiotics.

  • In mucopolysaccharidosis disorders, the body is unable to break down mucopolysaccharide sugar chains. These mucopolysaccharide sugars buildup in cells, blood and connective tissue: hence the name, ‘storage disorders’.
  • In general, most affected people appear healthy at birth and experience a period of normal development, followed by a decline in physical and/or mental function.
  • As the condition progresses, it may affect appearance; physical abilities; organ and system functioning; and, in most cases, cognitive development. 
  • Most cases are inherited in an autosomal recessive manner, although one specific form (Type II) follows an X-linked pattern of inheritance. 
  • Specific treatment can be provided via Enzyme replacement therapy or haematopoietic stem cell transplantation in the early stages. 
  • Presently, enzyme replacement therapy is available for MPS I, II and VI and is given as an intravenous infusion either weekly or biweekly, depending on the disease. 
  • Both enzyme-replacement and haemotopoietic stem cell treatments still have gaps and few clinical trials supporting them. (; Dornelles, 2014).

See the American APLS online sim scenario, page 54-57:

A neonate presents with extreme irritability and vomiting. Which laboratory tests can be most helpful in identifying an underlying inherited metabolic condition?

A: Ammonia

B: Glucose


D: Coagulation profile

The correct answer is A.

Irritability and vomiting are unspecific presentations for a broad range of neonatal conditions. Elevated ammonia can help differentiate towards a metabolic condition, such as organic acidemias and urea cycle disorders.

Hypoglycaemia with low ketones are an _______ response, it can lead us to think of _______ diagnosis. 

A: Appropriate, sepsis

B: Appropriate, diabetes

C: Inappropriate, diabetes

D: Inappropriate, fatty acid oxidation disorders.

The correct answer is D.

The body’s response to prolonged fasting is to break down fat to create ketones that will be used as an alternative source of energy. So in hypoglycaemic states, high ketones will be observed. If ketones are low, it’s because the body is unable to break down fat properly, such as in fatty acid oxidation disorders.

Which tests are part of the investigation of hypoglycemia?

A: Insulin and GH

B: Amino acids (plasma)

C: Ketones

D: All the above

The correct answer is D.

The basic screen aims to identify the most common endocrine or metabolic conditions responsible for hypoglycemia. Usually it involves: glucose, ketones (Beta-hydroxybutyrate), insulin, cortisol, Growth Hormone (GH), ammonia, lactate, free fat acids, serum amino acids, acylcarnitines profile (Guthrie card) and urine for organic acids and ketones.

Extremely high ammonia can be usually found in which condition?

A: Hyperinsulinism

B: Phenylketonuria

C: Urea Cycle disorders


The correct answer is C.

Although ammonia can be increased for a range of reasons (muscle activity, haemolysis, neonatal sepsis), however in urea cycle disorders these levels are the highest observed. The urea cycle is responsible for the metabolism of nitrogen waste from the breakdown of proteins, as one of these enzymes are deficient, it leads to an accumulation of ammonia as nitrogen cannot be metabolised to urea.

Which of the following is incorrect regarding Anion Gap (AG)?

A: The AG is the difference between primary measured cations and the primary measured anions.

B: Potassium (K+) is the most important cation for AG calculation. 

C: Commonly measured anions are Chloride and Bicarbonate.

D: AG is useful in understanding causes of metabolic acidosis. 

The correct answer is B.

If not available, the anion gap can be calculated without potassium, in this situation the reference range will be different (12 ±  4mEq/L).   

Adam , HH. Ardinger, RA. Pagon, S. E. Wallis, L. J. H. Bean, K. Stephens, & A. Amemiya (Eds.), GeneReviews® [online book].

Applegarth DA, Toone JR, Lowry RB. Incidence of inborn errors of metabolism in British Columbia, 1969-1996. Pediatrics. 2000 Jan;105(1):e10.

Dornelles AD, de Camargo Pinto LL, de Paula AC, Steiner CE, Lourenço CM, Kim CA, Horovitz DD, Ribeiro EM, Valadares ER, Goulart I, Neves de Souza IC, da Costa Neri JI, Santana-da-Silva LC, Silva LR, Ribeiro M, de Oliveira Sobrinho RP, Giugliani R, Schwartz IV. Enzyme replacement therapy for Mucopolysaccharidosis Type I among patients followed within the MPS Brazil Network. Genet Mol Biol. 2014

Sanderson S, Green A, Preece MA, Burton H. The incidence of inherited metabolic disorders in the West Midlands, UK.Arch Dis Child. 2006 Nov;91(11):896-9. 

Saudubray J-M, Baumgartner MR, Walter JH. (editors) Inborn Metabolic Diseases. Diagnosis and treatment. 6th Edition. Springer 2016. 

Please download our Facilitator and Learner guides

Constipation Module

Cite this article as:
Team DFTB. Constipation Module, Don't Forget the Bubbles, 2020. Available at:
AuthorRebecca Paxton
Duration30-60 mins
Equipment requiredNone
  • Basics (10 mins)
  • Main session: (2 x 15 minute) case discussions covering the key points and evidence
  • Advanced session: (2 x 20 minutes) case discussions covering grey areas, diagnostic dilemmas; advanced management and escalation
  • Quiz (10 mins)
  • Infographic sharing (5 mins): 5 take home learning points

We also recommend printing/sharing a copy of your local guideline.

Billy is an otherwise well 4 year old boy who presents to A&E with a 4 week history of abdominal pain. His pain comes and goes, and seems to be worse after eating. Today he has been doubling over with pain and crying inconsolably.

He has had no fevers or vomiting. He is drinking well but parents think he is a bit off his food. His last poo was 3 days ago, and parents think it was normal but aren’t sure.

What else would you like to know?

What would you look for on examination?
How would you treat Billy?

When should he be seen again?

What is your next step if he doesn’t respond to your treatment?

Red flags – make sure learners have thought to exclude red flags in their history and examination. These include:

  • History of delay more than 48hours in passing meconium
  • Ribbon stools
  • Faltering growth
  • Abdominal distension and vomiting
  • Abnormal anatomical appearance of the anus
  • Severe abdominal distension
  • Abnormal motor development
  • Abnormal gluteal muscles or sacrum
  • Spine or limb deformity (including talipes)
  • Abnormal power, tone or reflexes
  • Safeguarding concerns
  • Ensure external examination of anus for haemorrhoids/fissures that may need treatment 
  • Treatment – assess Billy for signs of impaction and start disimpaction regime if indicated. Discuss non pharmacological treatments.
  • Counselling – prepare parents for duration of treatment, possible side effects and importance of adherence
  • Follow up – prompt and regular follow up, tailored to the families needs
  • Treatment failure – discuss reasons for treatment failure, methods to tackle common problems
  • Red flags
  • Not responding to treatment after 3 months (thyroid, coeliac, allergy) 
  • Failure to thrive
  • Safeguarding concerns

Jakob is a  9 day old baby boy who is brought to the emergency department with vomiting. He is mum’s 3rd baby. Mum is worried that he is vomiting everything he drinks, and is sleepier than she would expect. He seems distressed when awake. He is having 3-4 light wet nappies per day but has only passed a few small stools in his short life.

What else would you like to know? 

What would you look for on physical exam?

Would you order any investigations?

What is your initial management?

  • Red flags on history – delayed passage of meconium and bilious vomiting
  • Examination- look for abdominal distention, careful examination of external genitalia and anus. Document weight and weight loss.
  • Discussion of PR examination – should only be performed by experienced practitioner. May result in forceful expulsion of gas/stool (highly suggestive of Hirschsprung’s). 
  • Investigations – order in consultation with surgical team. Consider abdominal XR to assess for obstruction but keep in mind the surgical team will likely perform contrast study. Rectal biopsy (under surgeons) for definitive diagnosis. 
  • Initial management – resuscitation. NG tube and IV fluids, correction of any electrolyte abnormalities. Look for signs of sepsis (enterocolitis).

Lily is an 8 year old girl with Trisomy 21. She had an AVSD repair as an infant, and is otherwise well and takes no medications. She has been referred to A&E by her GP with worsening constipation. She has been constipated on and off for most of her life, but this has usually been easily managed with movicol. This time around, she has been constipated for 3-4 months and is passing painful, hard stools approximately once per week. Her GP started her on movicol 3 months ago, which parents say she has been happily taking but it doesn’t seem to be working. 

What else would you like to know?

What investigations would you order?

What do you think might be going on?

How would you treat Lily?

T21 and constipation. Constipation is very common in Trisomy 21. Most often it is not due to an underlying disease, but a combination of low muscle tone, decreased mobility and/or a restricted diet. However, T21 is associated with an increased risk of autoimmune disease, including thyroid dysfunction, diabetes and coeliac disease – all of which might cause constipation.

Investigations can be done in an outpatient setting, in this scenario should be followed up by a community paediatrician. Screen for all of the above.

Laxative treatment is unlikely to be entirely effective until the underlying problem is corrected. However, depending on the severity of symptoms treatment escalation is appropriate. Lily doesn’t have any symptoms if impaction, but it may be worth escalating her movicol dose or considering the addition of a stimulant laxative whilst awaiting test results.

Advanced Case 2 (20 minutes)

Georgie is a 12 year old girl with severe autism. She is non verbal. She is otherwise well, but has had trouble with constipation in the past. Her parents attribute this to her being a “picky eater”. Georgie has had abdominal pain for the last 2 weeks, and has been passing small, pellet – like stools every 4-5 days. She has been having more “accidents”, and has been back in nappies for the last 7 days. She has been seen by the GP who has diagnosed constipation and prescribed movicol. She took this as prescribed for the first couple of days, but she is now refusing her medications. Over the past 4 or 5 days, Georgie has begun to refuse all food and will only drink sips of juice with a lot of encouragement. When parents try to give her medications or take her to the toilet, Georgie becomes very upset and aggressive. Her parents are very distressed and not sure what to do.

What are your management options for Georgie? 

Children on the autistic spectrum are more likely to have problems with constipation. Often this is due to a restricted diet, but may also be due to increased levels of anxiety around toileting.

  • Georgie requires disimpaction and this is not being achieved despite the best efforts of the family. There is no right approach to this scenario. Options include
    • Optimise setting and motivators for toileting
    • Change/optimise medications – try mixing movicol into juice, try changing to lactulose, add stimulant laxative
    • Admission for washout – nasogastric tube for washout +/- enema. Strongly consider sedation
    • General anaesthetic for manual disimpaction + washout
  • Support parents and empower them in decision making process
  • Involve multidisciplinary team – community supports will be important on discharge

Macrogol laxatives may cause “lazy bowel” if used for more than 2 months. True or false?

The correct answer is false.

There is some evidence of patients developing dependence on stimulant laxatives if used long term. However, macrogols are safe to use indefinitely without complication.

Which of the following is NOT supportive of a diagnosis of idiopathic constipation?

A: Loss of appetite

B: Ribbon like stools 

C: Urinary incontinence

D: Faecal incontinence

The correct answer is B.

Ribbon like stools suggest an anorectal malformation, and any history of this warrants further investigation. Loss of appetite, urinary and faecal incontinence can all be the result of constipation or faecal impaction. 

In a child with abdominal pain, the diagnosis of UTI makes constipation less likely. True or false?

The correct answer is false.

Constipation can lead to urinary retention and UTI, and as such the two can, and often do, co-exist.  A positive urine dip or culture doesn’t rule out constipation as a cause of abdominal pain. Don’t forget to think about constipation in the child with a history of recurrent UTI. 

National Institute for Health and Care Excellence. Constipation in children and young people. London: NICE, 2014. Available at 

The Royal Children’s Hospital. Clinical practice guideline on constipation. Melbourne: RCH, 2017. Available at

Zeevenhooven J, Koppen IJ, Benninga MA. The new Rome IV criteria for functional gastrointestinal disorders in infants and toddlers. Pediatr Gastroenterol Hepatol Nutr 2017;20(1):1–13.

Sampaio C, Sousa AS, Fraga LGA, Veiga ML, Netto JMB, Barroso Jr U. Constipation and lower urinary tract dysfunction in children and adolescents: a population-based study. Frontiers in pediatrics 2016;4:101.

Youssef NN, et al. Dose response of PEG 3350 for the treatment of childhood fecal impaction. Journal of Pediatrics. 2002;141(3):410-4

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Headaches Module

Cite this article as:
Anna McCorquodale. Headaches Module, Don't Forget the Bubbles, 2020. Available at:
AuthorAnna McCorquodale + Arie Fisher
Duration1-2 hours
Equipment requiredNone
  • Basics (10 mins)
  • Main session: (2 x 15 minute) case discussions covering the key points and evidence
  • Advanced session: (2 x 20 minutes) case discussions covering grey areas, diagnostic dilemmas; advanced management and escalation
  • Sim scenario (30-60 mins)
  • Quiz (10 mins)
  • Infographic sharing (5 mins): 5 take home learning points

We also recommend printing/sharing a copy of your local guideline. (2 min video) headsmart website contains around 20 min of reading around symptoms which could suggest an intracranial tumour (30 mins)
A good podcast including risk stratification, diagnosis and management of headache
Quality standard 42 and clinical guideline 150

This is a lecture and a podcasts from PEM Currents which talks succinctly about the emergency management of migraine in ED and the likely treatment outcomes.*yN2Xhv-M5PPerWzDVNt3sw.jpeg

Lecture by a US doctor specialising in headaches. Great review over the first 18 min of both the history and examination red flags and where she considers imaging. The second half is a question and answer session which is less useful.

(30 min video)

This is a lecture from a 2016 conference. It is pretty involved in the chronic management of headaches in children so quite advanced for the majority of attendees but might interest paediatricians who run follow up with outpatient clinics.

Headaches are common in children with 75% of children having experienced a headache by age 15. Our primary jobs in emergency are to provide effective symptom relief and filter out the headaches that are more likely to be concerning in their origin. The aetiology of headaches relies enormously on the history and, even in sinister causes, there are often few or no examination findings.

The most common cause of headache in children is a viral infection and the most worrying an intracranial space occupying lesion. Happily the latter is rare.

A good history is key:

  1. Onset, gradual or sudden?
  2. Location & severity, these questions will be incredibly age dependent. Younger children find localisation of pain difficult.
  3. Duration of the problem? How many times has this been reviewed and by who. Is there a lead professional. Be aware of cognitive bias created at this point by knowing what labels others have used. Here there should also be some investigation into what treatment strategies have been tried previously.
  4. Timing and associated symptoms? Compare a morning headache with some nausea/vomiting to one which worsens during the day and is relieved with sleep.
  5. Background medical history
  6. Family history sp of migraines. The presence or absence of this can be incredibly important when establishing aetiology. High prevalence of migraines running in families.

Full examination is necessary but here it should be stressed that abnormal neurological findings are rare in children with headaches. Where they exist there is a clear reason to pursue investigation by imaging, however, their absence cannot be wholly reassuring.

A 12 year old boy is brought to ED with a headache. He does not ordinarily suffer from headaches but today came home from school with a throbbing headache on the right side of his head. It is now 8pm and there has been no change. He has never been seen for headaches before but had a number of attendances for abdominal pain between the ages of 5 & 9 years.

On examination  you see an afebrile child, holding his head with his eyes closed. His neurology is otherwise normal (GCS 14 M 6 V 5 E 3).

What additional information would you consider important in the history?

What would be your next management steps?

Would you discharge this child?

With the additional history what are we trying to establish? Is this a primary or secondary headache. Here the presence of a family history of migraine can contribute to a likely ‘primary headache’ history. We also need to be clear about whether there is any possible infectious aetiology. How do we distinguish between a viral infection with a headache and meningitis? 

Clinical features suggestive of meningitis in children: a systematic review of prospective data, Curtis et al, Pediatrics 2010 – Having either a bulging fontanelle or neck stiffness (older child) increases the likelihood of meningitis by 8 fold

Without either of the above treating symptoms and re-evaluating seems reasonable.

  • The ongoing management of this child is based around clinical judgement of the underlying cause. There aren’t any features of space-occupying lesion (SOL) so it seems reasonable to proceed with either simple analgesia (with an antiemetic if migraine seems likely).

Treatment of pediatric migraine headaches: a randomized, double-blind trial of prochlorperazine versus ketorolac, Brousseau et al, Annuls of Emergency Medicine 2004

  • Migraine symptoms more optimally treated with analgesia with additional antiemetic with >90% resolution of symptoms at 3 hours compared to either analgesia alone (55% symptom resolution) or antiemetic alone (85% resolution)
  • Offer combination therapy with an oral triptan and an NSAID,or an oral triptan and paracetamol,for acute treatment of migraine with or without aura.
  • Acute migraine management on presentation to ED to consider is Chlorpromazine 0.25mg/kg (max 12.5mg) IV over at least 30 minutes with 10 – 20mL/kg sodium chloride 0.9% (max 1L); may cause hypotension, monitor BP.

A 2 year old girl is brought to your emergency with a headache. She has been unsettled at night and wakes slapping the back of her head. She has been seen on four previous occasions over a 5 month period with similar presentations (varying grades of staff involved including a paediatric consultant).

The first presentation was related to the appearance of her molars, an MRI was booked but cancelled as symptoms had resolved when the molars erupted. Subsequent attendances have been documented as teething.

The parents history corroborates the above. She is waking at night with increasing frequency and have come today because it has been worse over the past week. Full neurological examination is normal and she is developing normally. There are some areas of white bulging on the lower gums.

Are there any features here which suggest additional investigation is necessary?

  • If so, what would you plan?
  • If not, how do you proceed

What non-medical features of this cases should we be aware of?

  • There are red flags in this history, however, due to the ages of the child these are difficult to clearly elicit through the history. Waking at night holding the occiput would seem unusual and a primary headache at this age is less likely.
  • Given that clinical examination findings are unlikely even in sinister diagnoses, we should endeavour to find those red flags embedded in the history.
  • There are no neurological examination findings and the behaviour change is not sustained so here evidence would suggest that, although imaging is required, it should be of the most optimal type ie MRI

Children with headache suspected of having a brain tumor: a cost-effectiveness analysis of diagnostic strategies, Medina et al, Pediatrics 2001

  • Here is an optimal time to discuss cognitive bias. Many people had seen this child before, it is easy to ‘plan’ an MRI in a teaching session on headaches but in reality, if your consultant had seen and discharged this child with a diagnosis of teething how would you actually feel?
  • Much has been written on cognitive bias in business and it has been extrapolated to clinical medicine.  It could be useful to explore way we can individually become more aware of this as a process in day to day practice. (

A 13 year old boy presents with a headache. He has been seen on four previous occasions spanning your hospital and another local emergency department over a 6wk period. His mother is particularly distressed by the headaches as she has previously lost a child. The boy’s mother clearly voices her anxieties and feels that things are worsening. This morning she reports witnessing an episode of vomiting with some ‘shaky walking’.

It is clear during your assessment that the boy is less concerned than his mother about these headaches. Neurological examination is normal while seated as he fears this will bring the headache back on lying down.

How do you proceed, is any further information required?

What investigations are indicated?

In practical terms this history and examination will need elucidating from both the mother and child independently being sympathetic to the overlying anxieties this mother is carrying from her deceased child. In saying this, there are already red flags appearing here:

  • Worsening headaches
  • Morning vomiting
  • Shaky walking (might indicated cerebellar signs)
  • Refusal to move to a supine posture

Again, we have a normal neurological examination (aside from the whole examination being conducted in a seated position).

How is imaging arranged within your department? This boy does require neuroimaging, but what would happen, CT or MRI? Does a refusal to lie down constitute enough information for a non-contrast CT head in emergency?

As you are deciding to neuroimage this child, you may wish to discuss:

  • Process of gaining CT at different times of day
  • Who reports this
  • If there are abnormalities on the imaging suggestive of raised intracranial pressure, what are the local arrangements to discuss this and where will definitive treatment be arranged?

A non-contrast CT head was undertaken which showed an obstructive posterior fossa mass requiring intervention by neurosurgery. The child required urgent transfer to a different unit for definitive treatment. Some further discussion points could be:

  • How is a time critical transfer arranged in you department?
  • What staff should go and what skills set would be required?
  • What would you prepare for if you were transferring this child (not ventilated, with a 6 week history of headaches but whom you now know has significant hydrocephalus)?

A 14 year old girl arrives immediately following an ophthalmology appointment for a general paediatric review. She has been suffering from mild headaches which have been controlled with simple analgesia for 2 months. These last from 1-4 hours, usually after school and have not worsened over this period. In the past 4 weeks she has become more aware of intermittent visual changes. She sees flashes of colour or ‘lego bricks’ which fall across her vision. This occurs daily, usually in the afternoon. Her ophthalmology appointment was unremarkable, including fundoscopy.

She is afebrile and lucid with no headache currently. Full neurological examination including co-ordination is normal.

Does this girl fit criteria for additional investigations?

What would you do?

You are intending to discharge her, what follow up should be arranged?

We refer back to:

Children with headache suspected of having a brain tumor: a cost-effectiveness analysis of diagnostic strategies, Medina et al, Pediatrics 2001

as an evidence base for imaging. She would not meet the criteria for urgent imaging. Consensus opinion from the American Academy of Neurology would suggest neuroimaging should be considered on the basis of new headaches with some features suggestive of neurological dysfunction. With a normal neurological examination, which here includes fundoscopy by an ophthalmologist, time is on our side so if imaging is pursued this should be MRI. Here it might be pertinent to consider other investigative strategies:

  • Would blood tests offer additional value? If not in this particular case then might they help in the context of low grade fever?
  • Would you consider an EEG?

In this case headaches aren’t really the major feature as they are easily controlled with analgesia. These do not sound epileptic – episodes are too frequent to not have a non-visual epileptic manifestation by now and the associated headache is not severe so an EEG may not be helpful. In childhood, migraine can encompass many other features and headache may not be the most prominent. Where patients are being discharged counselling/advice cannot be underestimated. A headache (or symptom in this case) diary can be a fast track to diagnosis in the outpatient setting and can easily be started from an emergency setting. Taking the time to talk about what your number one diagnosis is, and what environmental strategies might help and what features should prompt a further review, prior to discharge is vital.

A 10 year old boy presents with a 2 day history of a headache. He was referred by the GP to rule out meningitis. He appears uncomfortable but is alert and cooperative. The pain is throbbing and bilateral with a degree of photophobia. There is nausea but no vomiting. He is coryzal and has a temperature of 37.8C. The heart rate is 105 BPM and oxygen saturation rate 99% in room air. Neurological examination does not reveal any abnormalities and he has no problem lying flat for the exam. There is no meningism. On systemic examination there is only mild costophrenic tenderness.

What is the next best step in the management of this patient?

If a urinalysis is requested it shows microscopic haematuria and microscopic proteinuria but no pyuria.

What is the next step?

Participants may become fixated on headache characteristics at this point and may wish to ask additional questions about the character, timing and intensity and about associated symptoms. But these are vague and unspecific in this case. There is a heavy clue in the systemic findings including a mild tachycardia, low grade pyrexia and costophrenic tenderness. This is where the focus should shift towards investigating the cause of all of the patient’s findings, not just the headache.

The blood pressure was intentionally omitted from the vignette, an omission which also occurs frequently in real life. If it is requested it’s revealed to be 161/102. If it is not requested the vignette can continue with the patient developing seizures, which constitutes hypertensive emergency. The cause appears to be renal and the history, clinical findings and urinalysis are more in keeping with glomerulonephritis then acute infection. The most likely is IgA nephropathy. The management is behind the scope of this discussion – starting an anti-hypertensive and consulting a renal service is appropriate in the first instance. Here it is demonstrated that headache can be a sign of systemic illness and a thorough history and exam is always required including a full set of vital signs.

A 12 year old girl presenting with a 2 month history of headache. The pain is throbbing, bilateral, worse at night and is accompanied by nausea. She is anxious as the headache is now affecting her sleep. The GP started her on Amitryptiline but she stopped it due to daytime somnolence. She has a history of chronic abdominal pain. There is a family history of essential hypertension and diabetes. She has long been bullied about her weight. Her BMI is >99th centile.

Her fundscopy examination is shown.

Are there any red flags in the history?

What is the most likely diagnosis and the differential diagnosis?

What are the most important aspects of the exam?

This patient has symptoms which could suggest increased intracranial pressure. Given the history idiopathic intracranial hypertension is probably most likely but other causes like mass or syringomyelia must be considered. If these are ruled out than a primary headache disorder is most likely. Participants will likely list important aspect of the neurological examination. Visual fields and extraocular movements are of particular importance to screen for complications of ICP and a thorough screen for lateralizing signs to outrule mass. Ultimately this patient will need a scan prior to lumbar puncture but these findings will determine urgency.

A bedside fundoscopy can be used as a test for papilloedema but is it really possible? Most children are not fully cooperative and most ED are equipped with direct ophthalmoscopes which give a very small field of view (a panoptic ophthalmoscope is better). Additionally, the exam is usually undilated, adding another layer of difficulty. Overall a reliable ophthalmoscopy under these conditions requires significant expertise, so it should not be relied on unless a specialist is available. If the history is concerning, than the child should be worked up.

Which of the following is not a sign of raised intracranial pressure when co-existing with a headache?

A: Increasing head circumference in <1 year old

B: Vomiting

C: Behavioural change/irritability

D: Fever

E: Waking from sleep with pain

The correct answer is D.

Fever may suggest meningism but not raised ICP. All the others are concerning features of raised ICP.

What is the investigation of choice in headaches with clinical neurological signs?


B: Non-contrast CT


D: Bloods including infection markers/clotting profile

The correct answer is B.

Children who present with headaches and clear neurological signs are the cases where an in department non-contrast CT is indicated. Where there are no clinical findings MRI is the preferred imaging modality.

In paediatric migraine, what is the most effective single treatment for children presenting to emergency?

A: Analgesia

B: Rest and reassess

C: Modify environmental factors

D: Antiemetic

E: Keeping a headache diary

The correct answer is D.

All of the above have a role in the treatment of migraine, however, in the acute setting evidence points to antiemetics are most effective in symptom relief. Analgesia and antiemetics together are even more beneficial. Modification of environmental factors, including rest/exercise/diet and keeping a diary of symptoms will not help acutely but hand some control to the patient in the long term management of symptoms.

Clinical features suggestive of meningitis in children: a systematic review of prospective data, Curtis et al, Pediatrics 2010

Treatment of pediatric migraine headaches: a randomized, double-blind trial of prochlorperazine versus ketorolac, Brousseau et al, Annuls of Emergency Medicine 2004

Children with headache suspected of having a brain tumor: a cost-effectiveness analysis of diagnostic strategies, Medina et al, Pediatrics 2001

Please download our Facilitator and Learner guides

Febrile Child Module

Cite this article as:
Team DFTB. Febrile Child Module, Don't Forget the Bubbles, 2020. Available at:
TopicFebrile child
AuthorSarah Timmis
DurationUp to 2 hours
Equipment neededNone
  • Basics (10 mins)
  • Main session: (2 x 15 minute) case discussions covering the key points and evidence
  • Advanced session: (2 x 20 minutes) case discussions covering grey areas, diagnostic dilemmas; advanced management and escalation
  • Sim scenario (30-60 mins)
  • Quiz (10 mins)
  • Infographic sharing (5 mins): 5 take home learning points

We also recommend printing/sharing a copy of your local guideline.

The expectation is for the learners to have watched or read one of the basic links before the session.

What is the deal with fever? a good overview of the approach to a febrile child

NICE fever guidelines for kids • LITFL covers the NICE guidelines, plus a bit more

If you prefer to listen rather than read, there is a podcast that although long, is worth listening to and covers the approach to a febrile child: (1hr 14 minutes)

Pediatric Fever Without A Source

Fever is one of the most common presentations to the paediatric emergency department; it scares parents and it makes children miserable. So why does fever occur? A fever is a natural physiological response to infection. It occurs when either an exogenous (eg micro-organisms) or endogenous (eg TNF, interleukin-1 or 6) pyrogen is activated. These pyrogens, via a number of mechanisms, activate the anterior hypothalamus which ultimately results in an increase in body temperature (The pathophysiological basis and consequences of fever).  

This is crucial to understand – your body is in control of your temperature. This is not something an infection is doing to your body; it is something your body is doing to the infection. Of note- this is different from pathological hyperthermia, where your temperature is elevated by either hypothalamic dysfunction or external heat. These are extremely rare. (Hot Garbage: Mythbusting fever in children)

The process of having a fever is believed to be a beneficial response to an infection. The mechanisms by which a fever helps protect you from infection include:

  1. Higher temperatures inhibiting growth/replication of pathogens
  2. Higher temperatures promoting the immune response to infection
  3. It is also worth noting that bacteria are killed more easily by antibiotics at higher temperatures, so there is also a potential third mechanism.

With all this considered, it is not the presence of the fever that is the issue, but what the reason behind the fever is. This is what we, as clinicians, need to discern. First of all, is it infection (most likely in the paediatric population), if so, is this a serious infection? Or is the fever caused by something else (malignancy, drugs, autoimmune, endocrine)?

A father attends the ED with his 4 year child, who has a 2 day history of fever, his most recent temperature was 39.9oC and this has prompted his visit to the emergency department. The father describes his child as being otherwise well, but is extremely concerned about the height of the fever.

Describe how you would assess the child?

What investigations and treatment options would you consider?

You are happy with your assessment of the child, and would like to discharge him, however his temperature is 38.5oC. How do you proceed?

Is this child sick?

The Paediatric Assessment Triangle (from DFTB)

In some instances it will be fairly obvious if the child is unwell, they just ‘look unwell’. A tool that can help you put a system to this assessment is the paediatric assessment triangle. Which considers the childs: appearance, breathing and circulation. This will let you consolidate what you are worried about and allow you to communicate this to your colleagues. 

If all these appear to be in order, this is a reassuring sign. A happy child playing in the waiting room, whilst eating a packet of crisps is much less likely to be unwell with a serious bacterial infection than one that is quiet. Remember to write what you have observed in your notes. 

NG143 Traffic light tool (from NICE)

Once you have some observations you can also use the NICE traffic light table – which helps categorise children into green (well), amber or red (potentially unwell). If they score red, you know they need further workup, and potentially quickly. Green, then they can probably wait a bit to be seen. 

Take a full paediatric history, specifically asking about:

Normal self?
Eating and drinking?
Passing urine?
Bowels opening?
Pulling at ears?
Rash/ lumps and bumps?
Siblings, anyone else unwell?

This should also give you an idea about how worried the parents are, is it just the temperature, or is it something else? A high fever with a child who seems their normal self is far less concerning than a child with a normal temperature that just isn’t right.

This needs to be thorough, given that the majority of these kids will be discharged without further investigation. This means looking in ears and throats, looking at the skin hidden under clothing, looking at joints, feeling pulses. So undress the child. You may find a petechial rash, a lump, or more likely, some very enlarged tonsils. Get the child to walk if they are old enough, and stand on one leg and then the other. And when it comes to ears and throats get the parent on board and show them how to hold the child properly. 

Whilst you are hunting for the source, also note the absence of one- look for the signs of the scary infections, the petechiae, the reduced air entry on a lung base, the red knee.

Are you happy examining a child? gives some top tips on how to examine different age groups

Also read for a step by step fever focussed examination guide

This step depends very much upon your assessment of the child. If you have found a source-treat that as appropriate. If full history and examination does not provide you with an answer, you have a fever with an unclear source. NICE helpfully has a set of guidelines for these: (NICE fever guidelines for kids • LITFL)

  • Investigate fever with no source if they have any red features –  this includes FBC, CRP, B/C and urine.  Consider LP, CXR, UEC and gas if indicated. 
  • Investigate fever with no source if there are any amber features unless deemed unnecessary by an experienced paediatrician. (this is the bit that could cause you to become unstuck, and you may want a senior to look over these)
  • Check urine for all children with fever (over 37.5) and no source, even if they are green (on the NICE traffic light systemt).

Consider the use of paracetamol or ibuprofen to bring down a high temperature in a hot and miserable child. If it makes the child feel better, it will make the examination process easier for everyone. NICE advises alternating antipyretics.

In many children with fever, the cause will be viral, the source of which may be obvious, or may still be unclear. If they are in a low risk group with a normal urine, they may be ok to go home with advice and a leaflet on the use of antipyretics, fluid management and safety netting advice. However as stated above these are only guidelines, if you are not happy you can always investigate, or admit for observation, and parents can always come back.

If the child has a fever but you have a well child that you have no concerns about then you do not have to wait for the temperature to come down before discharge. 

Give the parents advice on recognising red or amber signs by providing written information and/or arranging follow-up- most EDs will have a ‘fever’ leaflet to give to parents. 

Educating the parents about the nature of fever is important. Explain that “We treat fever with anti-pyretics because it makes the child feel bad, not because fever itself is bad.” Fever is due to a functional immune response. It is what is causing the fever that has the potential to do harm. As a result what the fever is, is not nearly as important as how the child looks or behaves. (The caveat being an under 6 month old where the height of fever is relevant)

On discharge tell them If the fever lasts for more than 5 days, the child should at least have a repeat physical exam by a clinician.

Finish with “But come back if you are worried about the child, even if you have only made it to the car park/ house/ doors of the ED”  
A good summary in video form on seeing a feverish child:

A 5 week old girl has been brought in by her mother. Her mother reports the child seemed irritable so she took her temperature and it was 38.2oC. Pregnancy and birth was unremarkable and there have been no concerns since her birth. The child is feeding well and the history and examination are unremarkable, observations in the ED have been within normal limits, apart from her current temperature which is 38.5oC. Your initial assessment has not provided you with an obvious source for the infection.

When is a temperature classed as a fever?

How would you investigate this child?

How would you manage this child if they had a white cell count of 17 x109/L?

NICE consider >38oC to be a fever

RCEM considers a temperature of 37.5-38oC to be a low grade fever 

However, most people would agree that the difference between .1 of a degree is not significant, therefore infants with a temperature of 37.9 vs 38oC should be managed in the same way.

This child is under 3 months old

Any child with a fever >38oC that is under 3 months old is at ‘high risk’ of serious illness (‘red’ on NICE’s traffic light table NICE fever guidelines for kids • LITFL). If they have a history of fever, but none on assessment remember to ask about antipyretics.

According to NICE this child requires bloods (FBC, CRP, Blood cultures), a urine sample and if the history and exam suggests, a chest X-ray and/ or a stool culture.

A lumbar puncture should be considered and is indicated if the child is:

  • less than 1 month 
  • 1-3 months and unwell; 
  • or 1-3 months with WCC<5×109/L or >15×109/L.

The discussion here is if the child is ‘unwell’, or not. You have a few tools that can help you – the paediatric assessment triangle and the NICE traffic light table (referenced in the above case) can help you decide. However if in doubt, the child will be investigated, and you should be speaking to the paediatric seniors.

If this child had a WCC of 20 then this is an indication for IV antibiotics. 

IV antibiotics are required for children under the same criteria that a lumbar puncture is indicated: 

  • if less than 1 month; 
  • 1-3 months and unwell; 
  • or 1-3 months with WCC<5×109/L or >15×109/L.

The choice of antibiotic will come down to trust guidelines.

A 7 week old has been brought in by her mother because she felt very hot today, and has been ‘a bit grizzly’. Mum has given paracetamol and brought her to ED. Her temperature is 37.6oC on triage. On initial assessment you have no concerns and remaining observations are within normal limits. 

How should a temperature be taken? 

How would you investigate and manage this patient?

NICE has recommendations on this:

Do not routinely use the oral and rectal routes to measure the body temperature of children aged 0–5 years.

They advise in infants under 4 weeks: 

  • measure body temperature with an electronic thermometer in the axilla 

In children aged 4 weeks to 5 years use one of the following:-

• electronic thermometer in the axilla

• chemical dot thermometer in the axilla

• infra-red tympanic thermometer

It’s worth checking what your department uses and what the parent has been using. 
There are some small studies with low numbers of patients that suggest that layers of clothing can raise the skin temperature by up to 2.5°C with a minimal rise in rectal temperature in the very young (Feel the heat). Therefore undress children who seem inappropriately overdressed.

For this patient, guidelines are helpful, but they will not tell us what to do.

We know that 

1. Any child with a fever >38°C under 3 months old is a ‘red’ on NICE’s traffic light system, and this makes them at high risk of serious illness.

2. NICE guidelines suggest that the parents subjective perception of a fever should be considered valid and taken seriously by healthcare providers. 

There is a temptation to treat a child who is apyrexial in the department differently to one that does have a fever. Consider:

  • Has this child had an antipyretic? 
  • In the young, mums are usually right (There is a study from 1984 that shows in children under 2 yrs, mums were correct 90% of the time when they thought their child had a fever, although this dropped to 50% accuracy in over 2 year olds.)
  • Those with fever at home are equally at risk as those with fever in the department (A BMJ study reports that infants <60 days of age, with a history of documented fever are at equal risk for bacteraemia or meningitis as those with fever in the department.

So in summary, we have an infant with a normal temperature, who probably had a fever this morning. There are at least two ways of managing this, one is to treat as a fever which therefore means bloods (FBC, CRP, B/C), urine and if history suggests, a CXR and or stool culture. Given that there was parental concern this is probably the preferable option. The other is a period of observation to see how the child progresses, and see whether or not they spike a fever. 

Given that there are no clinical concerns at present, antibiotics prior to blood results are not indicated.

For a debate surrounding overtreating infants read

A 3 year old boy has returned to ED with a history of 6 days of fever, they have seen the GP twice, two and four days ago, and told it was a viral illness. However the fever is persistent and his parents are concerned. His past medical history includes two admissions for viral wheeze when he was younger, but is otherwise unremarkable. All immunisations are up to date, he goes to nursery and lives with his parents, he has no siblings but his mother is 9 weeks pregnant. On examination the child seems grumpy, he has a fever of 38.8 and a HR of 150 he has a rash across his face and torso and evidence of conjunctivitis.

You think the rash looks morbilliform, what are your concerns and how will you proceed?

What other differentials should you consider, and what examination findings would you be looking for?

How would you work this patient up?

Measles – A brief historical & clinical review

The MMR in the UK is given at 12 months and 3yrs 4 months, so this child will have had the first immunisations affording him 80-95% protection, Measles therefore is unlikely but possible. Once he has had the second vaccination, this is quoted to afford 99% protection.  

Hopefully you are seeing this child in a side room, as measles can survive for up to 2 hours in air and is very contagious in the un-immunised population. 

It is likely wherever you are in the world, you will need to report this to your public health body. 

His mother is pregnant, check her vaccination status, if this is not complete and she has no history of disease, you need to advise her to see her GP ideally today, she may need a measles titre and, if this does not show previous exposure to the disease, human normal immunoglobulin (HNIG). You also need to enquire about other immunosuppressed/ non immunised contacts. 

A patient is infectious from 4 days before the onset of rash to 4 days afterwards, therefore he will need to be isolated until this period is up and nursery and other contacts need to be informed. 

Serum and saliva testing for measles is available.

Most children with measles can be discharged home

UK guidelines on managing measles exposure : Guidelines on Post-Exposure Prophylaxis for measles June 2019 


Recurrent or Periodic Fevers – investigate or reassure? 

Think infection, inflammation or neoplastic. We know infection is common in paediatrics, and the other two are less so. The list of differentials is probably almost endless. There is a good article which lists a whole heap of causes of fever in children, and investigations which can be performed. 

However with this presentation, it is important to consider Kawasaki disease with this time scale of fever and measles. Other conditions worth considering are listed below: 

• Streptococcal disease (e.g. scarlet fever, toxic shock syndrome)

• Staphylococcal disease (e.g. scalded skin syndrome, toxic shock syndrome)

• Bilateral cervical lymphadenitis

• Leptospirosis and rickettsial diseases

• Stevens-Johnson syndrome and Toxic Epidermal Necrolysis

• Drug reactions

• Juvenile Chronic Arthritis

Kawasaki Disease 

You are looking for evidence of Kawasaki disease: The diagnosis is made on the basis of the following clinical criteria (A + B):

A. Fever ≥5 days

B. At least 4 of the 5 following physical examination findings:

  • 1.Bilateral, non-exudative conjunctivitis
  • 2.Oropharyngeal mucous membrane changes – pharyngeal erythema, red/cracked lips, and a strawberry tongue
  • 3.Cervical lymphadenopathy with at least one node >1.5 cm in diameter
  • 4.Peripheral extremity changes 
    • acute phase: diffuse erythema and swelling of the hands and feet
    • convalescent phase: periungual desquamation (weeks 2 to 3)
  • 5.A polymorphous generalised rash – Nonvesicular and nonbullous. There is no specific rash that is pathognomonic for KD

This child has had a fever for 6 days, is tachycardic and the source currently is unclear. It may be measles, however this is not clear cut. He is therefore not going home. Depending on other findings on examination he may also fit the criteria for Kawasaki disease he certainly needs bloods, FBC, U+E, LFTs, CRP, ESR, cultures and a urine dip. He does not require IV antibiotics at this point.

Kawasaki Disease the first 4 minutes covers the presentation and investigation of Kawasaki disease

Communication: Septic screen , taken from  Simulation Library, PaediatricFoam

Which of these is true, a 60 day old with a temperature of 38.5oC:

A: Fulfils the criteria for a lumbar puncture

B: Can be discharged without further investigation 

C: Needs IV antibiotics

D: Needs urine sent for urgent microscopy and culture

The correct answer is D.

This child will need further investigation, at the least bloods and serum cultures, however if they are well they may not necessarily need antibiotics or a lumbar puncture. All children under 3 months need urine sent, not dipped. Use dipstick testing for infants and children 3 months or older.

Which of these is false?

A: The height of the fever can make a difference to the how the child is managed

B: If a fever doesn’t reduce with an antipyretic the child needs admission to hospital

C: A 28 day old with a temperature of 38.5oC will need FBC, CRP and Blood cultures

D: It is recommended that children aged 4 weeks to 5 years have their temperature taken with an axillary probe or tympanic thermometer

The correct answer is B.

A is true because the height of the temperature does make a difference to the management of those under 6 months old

Presence of a fever, even one that does not reduced with an antipyretic is not an indication of a serious infection. It is perfectly acceptable to discharge a well child with a fever, with good safety netting. 

Which of these is true?

A: Kawasaki disease can be diagnosed with fever for > 5 days plus 3 of the B symptoms

B: Fever of over 39oC in a 3-6 month old automatically needs a full septic screen 

C: The higher the fever, the more likely it is to be a serious bacterial infection

D: Measles is infectious from 4 days before the onset of the rash to 4 days afterward

The correct answer is D.

Kawasaki disease is diagnosed with fever >5 days and 4 out of 5 B symptoms

A fever of >39 in a 3-6 month may need a full septic screen, the temperature alone would push them into NICE’s ‘amber’ category. However it depends on a few factors, including whether there is an obvious source and NICE recommends a review by an experienced paediatrician before performing a septic screen automatically on these patients. 

C is not true, there is no good consistent evidence to suggest a higher fever means a more serious infection 

Please download our Facilitator and Learner guides

Head Injuries Module

Cite this article as:
Team DFTB. Head Injuries Module, Don't Forget the Bubbles, 2020. Available at:
TopicHead injuries
AuthorChris Odedun
DurationUp to 2 hours
Equipment requiredNone
  • Basics (10 mins)
  • Main session: (2 x 15 minute) case discussions covering the key points and evidence
  • Advanced session: (2 x 20 minutes) case discussions covering grey areas, diagnostic dilemmas; advanced management and escalation
  • Sim scenario (30-60 mins)
  • Quiz (10 mins)
  • Infographic sharing (5 mins): 5 take home learning points

We also recommend printing/sharing a copy of your local guideline.

Basics of head injury assessment 

RCEMLearning module on head injury (September 2018)

Managing more serious head injuries 

OPENPediatrics “Introduction to Traumatic Brain Injury” (February 2016)

Neuroprotective strategies for severe traumatic brain injury (Paediatric FOAM)

DFTB “Traumatic Brain Injury” (2013)

Your department/region’s guideline for managing head injuries in children.

Head injuries form a wide spectrum of clinical presentations. At their most simple, they can be defined as any impact to the body, proximal to the cervical spine & neck, excluding trivial impact to the face. Practitioners seeing any patient with head injuries should devote time to understanding the primary injury – the mechanism, including its biomechanics. 

They should also aim to develop expertise at identifying the cohort of patients at risk of secondary injury, from deviations of ICP, blood pressure, CO2, O2 & glucose.

Head injuries are generally defined by conscious level (Glasgow Coma Score/GCS) post-injury.  Head injuries are a very common presentation for children to emergency departments. The vast majority are trivial or minor, requiring observation and/or discharge advice only.

Head injuries remain one of the most common causes of serious morbidity & mortality in children (and young adults). Practitioners need to become skilled at selecting the cohort who require imaging – which is well established as CT. This is the best modality commonly available to detect more serious injuries – typically contusions, intra/extra-cerebral bleeds & skull fractures. Practitioners should become familiar with clinical guidelines & decision-support resources (eg. NICE) to help guide which patients need imaging.

An even smaller proportion of these injured children will go on to require neurosurgical intervention. Here, the practitioner’s role is to mitigate secondary injury, as above – with neuroprotective strategies.

Lastly, practitioners should be aware of the possibility of non-accidental injury, especially with regard to drowsy or unconscious infants, and remember that they have a role in safeguarding all children presenting to the ED, regardless of reason for presentation.

NICE clinical guideline CG176 – head injury: assessment & early management esp. 1.3 & 1.4.9, 10, 11 + this review of the 2014 changes to indications for CT and more [Tessa Davis, Anna Ings (BMJ)]

NICE clinical guideline CG176 – head injury: assessment & early management esp. 1.3 & 1.4.9, 10, 11 + this review of the 2014 changes to indications for CT and more [Tessa Davis, Anna Ings (BMJ)]

CT imaging became the imaging modality of choice during the 2000s/2010s in developed economies.  Since then, access to CT has generally widened, and become ubiquitous. Key to this in the UK has been the development of guidance by NICE, in 2014, with updates since – it guides management of head injury in children and adults.  A trio of cohort studies looking at outcomes of children with head injury were key to the development of the paediatric part of this guideline – please see references. Included below is a flowchart guiding CT use in children courtesy of NICE.

CHALICE (UK/2006) – highly sensitive but significantly less specific rule developed in the UK, later incorporated into the NICE guidance

PECARN (US/2009) – cohort study looking to identify low-risk group of paediatric patients who could safely not be imaged
CATCH (Canada/2010) – prospective multicentre cohort study from Canada looking to establish features for medium & high-risk for clinically significant traumatic brain injury

A 6 year old girl is brought in by ambulance to the ED you work in. She was playing on a climbing frame and fell off the top onto concrete, onto her head. Handover states that she was briefly knocked unconscious, then returned to a GCS = 15, but has become more drowsy en route to hospital.

On your initial assessment, there is a large swelling to the left side of her scalp and forehead, and there appears to be some blood leaking from her left ear. Her GCS is 12 (E3V4M5) but the rest of her vital signs are within normal limits.

Outline your management steps.

How soon do you want this child to have CT imaging?

The scan shows an extradural haematoma. How can you direct your team to prevent secondary brain injury?

  • This child needs immediate CT imaging of the head and their cervical spine – they are ideally managed by a trauma team, where the primary survey should ensure detection of any other injuries. If as likely, the cervical spine cannot be cleared clinically, they will need immobilisation until this is completed. A written report from an appropriate radiologist will ideally be available within 60mins of the scan.
  • Significant CT findings (see ‘Basics’) will need urgent discussion with a neurosurgeon, to determine if the child needs emergency surgery. If not, a clear management plan – who will monitor the child, and where? will need to be agreed.
  • This child may require intubation, for airway, oxygenation & ventilatory control, or for secondary transfer. Tranexamic acid may be used. Attention should be paid to pain management, and neuroprotective initiatives should be put in place (control of ICP, blood pressure, CO2, O2 & glucose – see the referenced paediatric FOAM article which provides a good summary of clinical management) 

You see a 20 month old boy in your ED, who was playing with his 6 year old cousin when he ran into an opening door at home. He cried immediately, and vomited around 10 minutes later. 

Having been brought into the ED, which is 20 minutes from his home, he has vomited twice more. There was no LOC or seizure activity, and other than looking nauseated he appears to be behaving normally.

To scan or not to scan?

What guidance do the parents/nursing staff looking after this child in the ED need?

How long will you observe for, and what if the child vomits again?

  • This child can probably be safely observed without immediate CT scanning – this management approach would be supported by NICE (see sections 1.4.9 and 1.4.10).
  • This case will hopefully provoke discussion about what constitutes a ‘vomit’, and whether there are any other plausible causes of vomiting, other than the injury itself. 
  • Learners could discuss what local provision they have for more extended observation of a child.
  •  Discussion of provision of verbal + written advice would also be pertinent.

A 9 month old child presents after rolling off a bed onto the floor. You see a 7cm swelling on his occiput. In the trauma call, he is held in mum’s arms and is crying.

You are unsure over how to proceed – the child definitely needs CT imaging, but how should we ensure they keep still?

  • Recap of CT guidance – “For children under 1 year, presence of bruise, swelling or laceration of more than 5 cm on the head”
  • Options for CT sedation: benzodiazepines vs. diamorphine/opiates vs. ketamine vs. intubation & ventilation – given a significant CT finding is possible. This would be a good opportunity to mention the 2020 revisions to RCEM ketamine sedation guidance (with associated DFTB commentary)

An 8 year old girl is brought in by her dad. She clashed heads with another player at basketball two days previously, and did not initially seek medical advice as she was ‘fine’. She had to leave school early today because she had trouble seeing the board & teacher, and felt sick. There are no focal neurological findings but there is a bruise on the parietal part of the scalp on the right, and you cannot feel the scalp.

  • Need for detailed history-taking around the delay in presentation – actively look for any safeguarding concerns
  • Should we have an altered threshold for CT imaging when presentation is delayed? This DFTB post is a useful summary of a paper relating to this cohort of patients – finding of a nonfrontal scalp haematoma or strong suspicion of a basal skull fracture were significantly associated with a clinically significant brain injury.

A 15 year old girl re-attends 10 days after being knocked unconscious for 10-15 seconds while jumping for a header playing football. She passed a pitchside concussion test and continued to play, but was substituted after saying she felt dizzy, and was seen in an ED. A CT scan was performed – which showed no bleed, contusion or fracture. 

She says she found it hard to concentrate on schoolwork for a week afterwards, but this is now normal. She wants to know exactly when she can go back to playing as she has an important match in 3 days.

What do you do?

  • Concussion describes the symptoms & abnormal function experienced by patients after a head injury, without any evidence of macroscopic brain injury. Its management is commonly misunderstood and poorly explained to patients and carers.
  • Management focuses on cognitive rest, avoidance of activities that trigger symptoms, and graduated return to cognitive activity & education.
  • Return to sport should also be graduated, with trial of light activity, and avoidance of sport with a risk of head impact until the patient has been reviewed by a clinician.
  • There is a significant risk of secondary concussion if sport/normal activity is returned to too soon after the initial injury 

Some excellent resources from:

You see a 4 year old with a head injury. All of the following are an indication for urgent CT imaging except:

A: GCS<14

B: Sign of a basal skull fracture

C: Focal neurology on examination

D: Post-traumatic seizure

E: Loss of consciousness for a few seconds

The correct answer is E.

NICE guidelines mention all of the above as indications for immediate CT except for LoC – if brief this is not an indication. If more prolonged (>5min), this would mandate observation in the ED for at least 4h after the time of injury.

In an intubated child with an extradural haematoma causing mass effect, the following are important considerations in managing intracranial pressure:

A: Managing untreated pain

B: Using RR or tidal volume to control pCO2

C: Keeping O2 saturations 94-98%

D: Keeping blood glucose tightly controlled between 4-8

E: Removing any constrictive neck devices (tube ties, cervical collars etc)

The correct answer is D.

Evidence for tight glycaemic control has been superseded by the risks associated with hypoglycaemia for the injured brain. Prevention of hyperglycaemia would be a more sensible aim. All of the other answers would minimise increases in intracranial pressure, including aiming for a low-normal pCO2.

When managing children with head injuries, which of the following statements are true?

A: If the mechanism of injury is dangerous, the cervical spine should be CT imaged along with the head.

B: It is good practice to discuss management of delayed presentations with a senior before discharge

C: 3 vomits in 10 mins constitutes separate ‘episodes’ of vomiting.

D: CT imaging is essential in those with haemophilia.

E: Intranasal diamorphine can be used to manage pain and keep a child still for scanning.

The correct answers are A, B, and E.

If the child’s head is being imaged with CT, best practice would be to extend to the cervical spine if concern exists regarding injury. Teams should use judgement of the mechanism, presence of abnormal neurology and GCS to help make this decision). 

Evidence would suggest that presentation >24h after a head injury is associated with more significant findings, thus the threshold for scanning may need to be altered. 

Clinical judgement needs to be exercised with regard to vomiting. NICE refers to a vomit being a ‘single discrete episode’ but does not explicitly define timing. Our practice would suggest significant time for recovery should be allowed between episodes eg. 20mins.

Diamorphine is a good analgesic for young children and its sedative effects can be harnessed when attempting to safely CT in mild agitation – although other options are more safe if airway protection is required.

Congenital bleeding diatheses such as haemophilia require a lower threshold for imaging, and would need urgent supplementation of clotting factors – but very minor trauma to the head may still be managed without CT.

Please download our Facilitator and Learner guides

Analgesia and Procedural Sedation Module

Cite this article as:
Team DFTB. Analgesia and Procedural Sedation Module, Don't Forget the Bubbles, 2020. Available at:
TopicAnalgesia and procedural sedation
AuthorLauren Shearer
DurationUp to 2 hours
Equipment requiredNone
  • Pre-reading
  • Basics (10 mins)
  • Main session: (2 x 15 minute) case discussions covering the key points and evidence
  • Advanced session: (2 x 20 minutes) case discussions covering grey areas, diagnostic dilemmas; advanced management and escalation
  • Sim scenario (30-60 mins)
  • Quiz (10 mins)
  • Infographic sharing (5 mins): 5 take home learning points

We also recommend printing/sharing a copy of your local guideline for sharing admission criteria.

Lily, 4 years old, presents to the ED with her mother after falling from a scooter whilst in the park. She is holding her arm and not using it. There is no obvious gross deformity.

How would you do a pain assessment in this age category?

What would be the optimum analgesia choice based on a severe pain score?

What other methods or non-pharmacological adjuncts can be used?

When should we reassess the pain?

See RCEM Pain in Children – Best Practice Guidance for a guide on how to assess pain.

Consider different assessment tools:

  • FLACC (Face, legs, activity, cry, and consolability)
  • Wong Baker Faces
  • Visual analogue scale

See the analgesic ladder (RCEM guidance above and the WHO pain ladder).

Adjuvants should be considered in all steps of the ladder.

Bottom of the ladder is the most commonly used paracetamol (at 15mg/kg/dose) and non-steroidal anti-inflammatory drugs (NSAIDs). Paracetamol is an antipyretic and weak analgesic. It is used for the treatment of mild pain and fever associated with a sore throat or illness. But we should avoid oligo-analgesia and use the right drug for the right kind of pain.

Moving up the ladder are weak opioids like codeine. Codeine (an inactive compound of morphine) is no longer recommended for the management of acute moderate pain, particularly in children under 12 years with obstructive sleep apnoea or for post tonsillectomy procedures. Codeine must be metabolised by the cytochrome P450 enzyme 2D6 to the active compound, morphine, to relieve pain. Poor metabolisers of codeine may metabolise only up to 15% of the morphine concentration, receiving little or no analgesia from codeine. Ultra rapid metabolisers may metabolise up to 50% more morphine than normal metabolisers – which is potentially life threatening.

Children with moderate to severe pain should receive opioids together with non opioids. Morphine, oxycodone, hydromorphone are all active compounds that do not require the enzyme conversion to provide analgesia. Fentanyl, a synthetic opioid, has few, if any cardiovascular side effects. This is in contrast to morphine which may exacerbate hypotension with its vasodilatory effects. So in haemodynamically unstable children, fentanyl may be the preferred choice for acute pain management.

It’s easy to use, it’s needle-less, and decreases the overall need for utilisation of IV or IM routes which is a positive change in parent and patient satisfaction. It bypasses first pass metabolism permitting rapid and predictable bioavailability (compared with oral and intramuscular routes) and offers direct CSF delivery via the nose- brain pathway route

The maximum volume of IN medication permitted is 1ml per nostril and in cases of nasal trauma or septal defects, IN Fentanyl of course cannot be used. Rule of thumb, the IN dose is 2-3 times the IV dose.

Administer intranasal medications in the sniffing position. Lie the patient flat with occiput posterior, put patient in the sniffing position, seat the mucosal atomizing device cushion in the nostril, aim toward the pinna of the ear, and shoot fast – you have to push the drug as fast as you can to atomize the solution.

IN medication can be used for sedation, anxiolysis, pain control and seizure management. A 2014 Cochrane review on intranasal fentanyl concluded that it can be an effective analgesic for children aged 3 years and above with acute moderate to severe pain. Studies have demonstrated INF to result in decreased time to medication administration and equivalent pain control when compared to IV morphine, oral morphine or IV Fentanyl. IN Fentanyl (1.5mcg/kg) has become an excellent alternative to morphine in the ED, it has a greater safety profile and is easily available in the ED.

How does it compare to IN Fentanyl? One study demonstrated a similar pain reduction in children with moderate to severe pain from an isolated limb injury in the Paediatric ED, although the sample size was small and there was no comparator or placebo group. Adverse effects were more frequent with ketamine; however, these were all relatively mild (drowsiness and dizziness). Also, practically speaking, pain control doses for the IN Ketamine route at 1mg/kg mean that volumes for most children weighing above 10kg will exceed 1ml per naris if the ketamine concentration 10mg/ml is used.

An alpha-2 receptor agonist (like clonidine), does not markedly decrease blood pressure. Dexmedetomidine targets receptors in the CNS and spinal cord, and so it provides deep sedation, with very minimal blood pressure effects. It induces a sleep-like state. In fact, EEGs done under dex show the same pattern as seen in stage II sleep. Dexmedetomidine is safe, if titrated, and does not depress airway reflexes or respiration. Dose is 2.5 mcg/kg IN, and can add another 1 mcg/kg if needed. The downside is that it can last 30 minutes or more, but it may be a good choice for an abdominal ultrasound or CT head.Inflicting Pain with an IV to relieve pain is not something that makes sense to young children. IN medication offers pain relief prior to getting intravenous access and can even obviate the need for IV access if definitive care such as a cast, suturing, reduction of bony injuries can be done during the duration of action of the IN medication.

It is important these are thought about in conjunction with pharmacological techniques. These include:
Play specialists

  • Distraction techniques
  • Music
  • Games
  • Don’t forget the Bubbles

Immobilisation of injuries


  • Right people
  • Right place  
  • Right time

Parental/carer anxiety

Sucrose, and non-nutritive sucking interventions exert analgesic effects independent of the opioid pathway. Swaddling/facilitated tucking (preterm) and skin to skin care significantly increase B-endorphin levels.

Rocking/holding neonates and breastfeeding during minor procedures have all been shown to decrease objective measures of pain such as heart rate and crying.

Pain should be assessed on arrival and then monitored throughout their time in the emergency department and if appropriate beyond. Children in moderate and severe pain should have their pain reassessed within 60 minutes of receiving analgesia.

Frank, 8-years-old, was playing in the street with friends and fell over. He cut his knee on some broken glass and sustained a 4 cm laceration over his patella. An x-ray shows no foreign body and no fractures. The knee is swollen and the laceration requires suturing. On pain assessment he is reporting mild pain.

What are your initial considerations?

What are the options for cleaning and closing?

Don’t forget oral analgesics (as above) and a full assessment for other injuries.

  • Unsuitable for under 1s
  • Takes 20-30 minutes to work
  • Skin will blanch when ready
  • Max dose: 2 mls for 1 -3 year; 3 mls for >3 years
  • Not for use on: mucous membranes; extremities; wounds >8 hours old
  • Can be used in conjunction with local anaesthetic infiltration
  • Max dose not to exceed 5mg/kg
  • Inject slowly to reduce pain
  • Small gauge needle to reduce pain
  • Doses: 3mg/kg lidocaine

EMLA cream (lidocaine 2.5% and prilocaine 2.5%) is effective at numbing the tissue below intact skin to a depth of 6-7mm if left on for 30-60 min but does cause vasoconstriction which can be problematic if looking to cannulate.

LMX4, a topical liposomal 4% lidocaine cream like EMLA has full effectiveness by 30 minutes.

  • Play specialist
    Distraction techniques appropriate to age
  • Preparation of the child and area
  • Quiet setting
  • Parental/carer involvement
  • Using appropriate language

Freddie, 9 years old, attends the emergency department after falling from the monkey bars. He has sustained a displaced and angulated supracondylar fracture. He has some tingling at the fingers in the ulna distribution and therefore requires urgent manipulation. You decide to use nitrous oxide.

Do you need any pharmacological adjuncts?

What about non pharmacological?

What other considerations should be made?

Nitrous oxide provides anaesthesia, anoxiolysis and some mild amnesia but offers limited analgesia. Administration of analgesic supplements is recommended. Many papers including the FAN study demonstrate the safety and efficacy of co-administering intranasal fentanyl. Other analgesics can also be safely used.

There are two methods of delivering nitrous oxide, piped nitrous oxide and Entonox. Piped nitrous oxide can provide variable concentrations and can be titrated to response, whereas entonox is a fixed 50/50 mix of nitrous and oxygen and comes in canisters. The canister is set up with a demand value that needs to be overcome with a deep breath; this can be difficult for under 5’s.  You should see onset of effect in 30-60 seconds with the peak effect at 2-5 minutes. Offset of effects is similar at 2-5minutes, 100% oxygen should be applied during this time post procedure to avoid diffusion hypoxia.

Side effects are minor and transient but include:

  • Nausea
  • Vomiting (6-10% children receiving 50% dose). Increases incidence with higher dose, longer duration and concurrent opioid use. Consider prophylactic antiemetic if child has history of nausea or vomiting.
  • Dizziness
  • Nightmares

Nitrous oxide diffuses through tissues more rapidly than nitrogen alone and can expand in air containing spaces within the body, so it is contraindicated in:

  • Pneumothorax
  • Pneumocephalus
  • After diving
  • Gastrointestinal obstruction

Nitrous oxide inactivates the vitamin B12 dependent enzyme, methionine synthase and can deplete the B12 stores.  Therefore caution is advised in those at risk of vitamin B12 deficiency (vegetarians, patients with gastrointestinal disorders and those taking regular H2 receptors and proton pump inhibitors)

Despite the absence of use of intravenous sedative drugs, it is best practice to manage this patient in a high dependency setting, with monitoring including; respiratory rate, heart rate and oxygen saturations and at least 2 members of staff where one’s job is entirely focused on the sedation and monitoring of the child.

Guided imagery would work well in this setting with a trained practitioner.  This is a process where a variety of techniques can be used such as simple visualisation, story telling, direct suggestion imagery and fantasy exploration to elicit a physical response such as a reduction in pain, stress or anxiety.

Lola, 2 years old, has fallen in the playground and sustained a laceration to the forehead. Lola had an ice cream after the incident in an attempt to settle her. She has no past medical history and was born at term. Can she have procedural sedation in the department? What are the considerations?

What drugs do you need for the sedation? Should you use any adjuncts with the ketamine? Are there any emergency drugs you should have available?

There are no contraindications and you decide to go ahead with ketamine sedation, during the procedure whilst full monitoring in place the CO2 trace is lost.  What is your structured approach to management of this scenario?

A through pre sedation assessment is required to assess ASA grade, examine airway anatomy and illicit any contraindications listed below

Multiple studies have shown that fasting does not reduce the risk of aspiration or increase the risk of adverse events and the 2020 updated guidelines for ketamine sedation in the ED have echoed this. They advised that the fasting state should be considered in relation to the urgency of the procedure, but recent food intake should not be considered a contraindication to ketamine use. 

RCEM states the procedure should be carried out in an area with immediate access to full resuscitation facilities; three practitioners should be present throughout, one for the sedation, one for the procedure and one for monitoring and assistance. The updated 2020 guidance has included capnography in the mandatory monitoring required along with heart rate, ECG, blood pressure, respiratory rate and oxygen saturations. While there is no evidence that shows that capnography reduces the incidence of adverse events, there are studies that show capnography decreased the incidence of hypoxia and respiratory events. 

Oxygen should be given prior to the procedure if possible and during to reduce the time to de-saturation should an adverse event occur.

Ketamine is a NMDA receptor antagonist. It is a dissociative anaesthetic, a potent analgesic and amnesic. Ketamine induces a trance like state, often with the eyes open. It maintains the airway reflexes and maintains cardiovascular stability.

The RCEM accepted dose is 1mg/kg over 60 seconds. A rate of 60 seconds reduces the incidence of adverse events such as laryngospasm. A top up dose of 0.5mg/kg can be used if necessary. Onset is within 1 minute and will elicit a horizontal nystagmus and a loss of response to verbal stimuli. The HR, BP and RR may increase slightly. Sedation will wear off after 20 minutes and full recovery should occur by 60-120 minutes. RCEM no longer advise the use of IM ketamine as they suggest it is safer to have IV access available from the start of the procedure should an adverse event occur.

Midazolam: a 2018 BestBets review looking at 6 studies including 2 RCTs has shown that prophylactic benzodiazepines do not significantly decrease the incidence of emergence delirium and they in fact can increase the risk of adverse events, so they should not routinely be given prophylactically. However, midazolam can be used to treat severe emergence, especially in older children. (Aliquots of IV 0.05-0.1mg/kg can be given)

Atropine: atropine was previously used prophylactically to reduce secretions however there is no evidence to support its routine use to prevent laryngospasm or other adverse airway events and again it may increase the rate or adverse events. (Green et al)

Ondansetron: may be appropriate for patients at high risk of vomiting due to ketamine’s emetogenic properties. High-risk groups include those with previous nausea/vomiting during sedation/anaesthesia, older children, those who have received opioids or where ketamine is given intramuscularly. Caution should be used in those at risk of long QT.

Emergency drugs: RCEM suggests key resuscitation drug dose calculations should be done prior to the procedure and these should be accessible, however, no specific drugs are recommended. We suggest that WETFLAG dosing should be done along with the dose calculated for suxamethonium (1.5mg/kg for RSI).

Complications are rare with ketamine. A recent study by Bhatt et al in 2017 (6,760 patients across 5 sites in Canada) looking at propofol, ketamine, propofol/ketamine and ketamine/fentanyl, ketamine alone recorded the lowest serious adverse events at 0.4%. Green et al (2009) showed a 1% risk of noisy breathing requiring airway repositioning, a 0.3% risk of laryngospasm and 0.02% risk of intubation being required.

The capnography trace is there to provide early warning of potential or impending airway and respiratory adverse events. A loss of capnography trace indicates apnoea or obstruction. First check the equipment and monitoring is still in place then check for chest wall movement. If the chest wall is not moving then there is central apnoea. If there is chest wall movement there is obstruction. Airway manoeuvres will relieve obstructive apnoea but will not relieve laryngospasm.

10-year-old boy fell from the top of the climbing frame, landed awkwardly on his left ankle. Primary survey shows no other injuries except obvious deformity of the left ankle.

Summary: procedure appropriate for sedation – post procedure simple airway issues due to obesity

Faculty required: operator/Voice of patient/Nurse in scenario

Vitals: HR 120, BP 105/60, Sats 99%, RR 20, ETCO2 4.2, ECG NSR

Neurovascular compromise of the foot, CRT delayed

PMH: nil

BH: term, nil complications

DH: nil

NKDA, UTD with immunisations

Last ate 2 hours prior

  • Check full medical history
  • ASA status
  • Airway assessment (loose tooth, excess body fat)
  • Ensure appropriate setting (RESUS)
  • Appropriate equipment and monitoring (ECG, EtCO2, Sats, HR, RR, BP, suction, tilting table, resuscitation facilities)
  • Describe consent
  • WETFLAG calculations plus emergency drug calculations
  • Choice of appropriate drugs and dosing for sedation
  • Ensure appropriate staff
  • Pre-oxygenation
  • Checks patient during procedure
  • Checks equipment
  • Chest wall movement
  • Simple patient positioning and airway manoeuvre opens the airway and CO2 trace returns  
  • Describes post procedure monitoring
  1. Emphasis on appropriate preparation
  2. Systematic approach to adverse events and when to anticipate them

When should you assess a child’s pain and document a pain score in the emergency department when they present with an injury?

A: Wait until the child is seen by a doctor before assessing pain

B: At triage

C: Immediately after giving oral analgesia

D: Within 60 minutes of receiving analgesia for moderate and severe pain

E: When the child or the child’s parents informs you they are in pain

The correct answer is B + D.

A child’s pain should be assessed on arrival in the emergency department, and should be treated appropriately in a timely manner (within 20 minutes for moderate and severe pain). Pain should also be re-evaluated within 60 minutes of receiving analgesia for moderate and severe pain. This process should be repeated for all subsequent doses of analgesia. Reviewing pain should take into account peak of onset for the analgesia given; as such oral analgesics will not work immediately.

Which of the following predict possible airway difficulties in children?

A: C-spine immobilisation

B: Premature birth requiring NICU

C: Trisomy 21

D: Mouth breathing or frequent drooling

E: Reduced mouth opening

All are true.

A through pre assessment prior to sedation should be done to elicit any potential complications and also decide on appropriateness of sedation in the emergency department.

A formal airway assessment should include:

  • Mouth opening
  • Assessment of dentition for loose and protruding teeth
  • Tongue size
  • Presence of soft tissue masses in the mouth
  • Mandible size
  • Neck mobility
  • Tempero-mandibular joint mobility

A review of the child’s medical history should also include, congenital abnormalities, birth complications, previous complications during anaesthetics or sedation, noisy breathing, sleep issues and concurrent upper respiratory tract infections.

Please download our Facilitator and Learner guides

Anaphylaxis Module

Cite this article as:
Kat Priddis. Anaphylaxis Module, Don't Forget the Bubbles, 2020. Available at:
AuthorKat Priddis
DurationUp to 2 hours
Equipment requiredAdrenaline auto-injector if planning a demonstration on a model
  • Basics (10 mins)
  • Main session: (2 x 15 minute) case discussions covering the key points and evidence
  • Advanced session: (2 x 20 minutes) case discussions covering grey areas, diagnostic dilemmas; advanced management and escalation
  • Sim scenario (30-60 mins)
  • Quiz (10 mins)
  • Infographic sharing (5 mins): 5 take home learning points

We also recommend printing/sharing a copy of your local guideline.

Anaphylaxis is a severe, life-threatening, generalised or systemic hypersensitivity reaction.

Anaphylaxis is described as

  • Sudden onset and rapid progression of symptoms 
  • Life-threatening Airway and/or Breathing and/or Circulation problems 

*Skin and/or mucosal changes (flushing, urticarial, angioedema) are absent 20% of cases*

Angioedema is similar to urticaria but involves swelling of deeper tissues, most commonly in the eyelids and lips, and sometimes in the mouth and throat.

There can also be gastrointestinal symptoms (e.g. vomiting, abdominal pain, incontinence).

Fatality <1%, increased in those with pre-existing asthma. Approximately 20 anaphylaxis-related deaths in the UK every year. 

From a case-series (resus council), fatal food reactions cause respiratory arrest typically after 30–35 minutes; insect stings cause collapse from shock after 10–15 minutes; and deaths caused by intravenous medication occur most commonly within five minutes. Death never occurred more than six hours after contact with the trigger. 


What is an allergy?

It is the body’s response to an external ‘allergen’. An unnecessary immune response to an innocuous substance. 

Common allergens/triggers include: • Food: nuts, milk, fish • Venom: wasp, bee • Drugs: antibiotics, anaesthetic drugs • Contrast media • Latex

Reactions are either delayed type IV or immediate type I. IgE-mediated allergy is broadly characterised as a Type 1 hypersensitivity. Other hypersensitivity reactions (II, III and IV) are mediated by other antibody classes, immune cells or cellular components. Non-IgE mediated reactions typically cause symptoms to appear more slowly, sometimes several hours after exposure. 

Allergy is increasing in prevalence. Theories for this include the ‘Hygiene Hypothesis’, the idea that increased exposure to microorganisms correlates with a decreased tendency to develop allergy and more recently the ‘Old Friends Mechanism’ which links the tendency to develop allergy to an individual’s microbiome (collection of microorganisms living in and on an person’s body). 

Interestingly, kids in developing countries have a decreased allergy prevalence, thought to be because of less sanitation, more exposure to microbes and increased time spent outdoors. 

How do we develop allergic reactions? 

Part 1: Sensitisation

An allergen enters the body and is captured by an antigen presenting cell, that scoops it up and nicely presents it immune cells, particularly T cells (in a similar manner as if the allergen was a foreign invading microbe). Through a number of immune interactions between T cells and B cells, B cells produce allergen-specific IgE antibodies. These get released into the blood, where they bind to mast cells (the major allergy immune cell) as well as other friends like basophils. In some individuals, this can cause a ‘sensitisation’ i.e. the next time their body meets that particular allergen it’s going to go on the offensive. 

Part 2: Re-exposure

Our patient is now carrying allergen-specific IgE bound mast cells. Upon re-exposure, the offensive allergen binds to IgE, causing the mast cells to initiate an aggressive and immediate immune response. 

Mast cells on the attack: 

Mast cells are granular cells, containing many secretory granules that all get released on activation. The binding of IgE causes rapid degranulation, and a shower of inflammatory compounds, including histamine. Result? Local inflammations, and allergy symptoms (see presentation of the patient in anaphylaxis below). 

An 8 year old girl presents after collapsing following attendance at a friend’s birthday party. She was noted to have been eating a sandwich, then promptly developed respiratory distress. On admission with the ambulance crew she is audibly wheezy, with swelling of the tongue and lips.

How would you assess this child?

What is your immediate management?

How much adrenaline do you give and how? Any adjunct therapies to consider?

Usually the parents or child will give a history of exposure to an allergen. This is useful however not essential. If the clinical picture is of anaphylaxis – treat first and seek the provoking agent second!

Life-threatening features of anaphylaxis include:

  • Airway: swelling, hoarse voice, stridor 
  • Breathing: shortness of breath, tachypnoea, wheeze, cyanosis, respiratory arrest 
  • Circulation: pale, clammy, tachycardia, low blood pressure, shock, cardiac arrest
  • Confusion, agitation or decreased level of consciousness can occur due to above problems
  • Remember the ABCDE approach
  • Get senior help 
  • Remove the allergen if possible – remove a stinger, stop IV drugs, but don’t make a patient vomit if suspected food allergy – risk of aspiration. 
  • Maintain oxygen delivery 15l via non-rebreather mask
  • Get monitoring on – and get a BP early
  • If hypotensive then get IV access and bolus 20mls/kg 0.9% sodium chloride

Delayed administration is directly linked with increased morbidity and mortality 

  • Scientific evidence is weak, instead based on what is considered safe and practical. 
  • Adrenaline IM – use 1 in 1000 (or 0.1% – 1mg/ml)
  • The dose is 0.01ml/kg or 0.01mg/kg. Max dose is 0.5ml. 
< 6 years old
150 micrograms IM (0.15 mL)
6 – 11 years old300 micrograms IM (0.3 mL)
>12 years old500 micrograms IM (0.5 mL)
  • Give as an IM injection into the anterolateral thigh. IM provides faster rise in plasma and tissue concentrations than sub-cutaneous route. 
  • Don’t give IV boluses unless there is cardiac arrest. 
  • Can use the patient’s own adrenaline auto-injector if not already used

Alpha receptor agonist 

  • Reverses peripheral vasodilation
  • Reduces oedema

Beta receptor agonist

  • Bronchodilation
  • Increased force of myocardiacl contraction
  • Suppresses histamine and leukotriene release
  • Inhibits mast cells – attenuates severity of IgE-mediated allergic reactions. 

Normally only occur with IV administration (at which point PICU will be present)

  • Arrythmias
  • Hypertension
  • Pulmonary haemorrhage
  • Intracranial haemorrhage
  • Rapid onset – should see improvement in 5 minutes
  • Duration of action is 15 minutes – beware of rebound
  • Absolutely – 20% of patients require more than one dose! 
  • By the third dose please call PICU
  • Is the child wheezing? Consider a salbutamol neb 2.5mg/5mg depending on age
  • Antihistamines (H1 and H2 blockers) are a second line treatment and should not delay adrenaline administration! Examples such as chlorpheniramine are useful for urticaria, nasal and ocular symptoms
  • Steroids – think about steroids. 1mg/kg prenisolone (PO) or 4mg/kg hydrocortisone (IV) – but remember slow onset of action. 
  • Keep patient comfortable and minimise distress
  • Ideally have them lying down to aid venous return (hypotension can precipitate cardiac arrest)
  • NICE evidence: Limited evidence from systematic review – consider mast cell tryptase investigations only if reaction is thought to be drug, venom or idiopathic related! Send three timed samples. Immediately after reaction has been treated. 1-2 hours after the start of symptoms. At 24 hours or in convalescence (baseline sample) after the reaction.

A 3 year old presented with a localised erythematous rash after being stung by a bee at a family picnic. His family attended PED where he subsequently developed respiratory distress and he was treated with IM adrenaline. After a couple of hours he was playful and appeared well and his parents want to take him home.

What would you say to the parents?

How would you manage this patient?

What key points make up the discharge planning? 

  • Occur in 6–11% of children.
  • Usually manifest in the first 8 hours after exposure, but may be delayed up to 72 hours.
  • NICE evidence: children who have had emergency treatment for suspected anaphylaxis should be admitted to hospital under the care of a paediatric medical team. No direct evidence from systematic review however in light of risk of biphasic reaction risk, better to keep them in overnight for observation. 
  • All children with suspected anaphylaxis will require risk planning and allergy avoidance advice
  • Corticosteroids have been advocated to prevent protracted and biphasic reactions (no RCT on this). Recent systematic review and meta-analysis (Lee et al) included 27 studies with 4114 anaphylaxis cases, of whom 192 (4.7%) had biphasic reactions. 
  • Steroid administration did not affect the likelihood of a late phase reaction (OR 1.52, 95% CI 0.96 to 2.43). In fact, there was a non-significant trend towards increased risk, (?because steroid use was more common with severe reactions). 
  • Biphasic reactions were more common where hypotension was present at initial reaction (OR 2.18, 95% CI 1.14 to 4.15), but this is unusual in food-induced anaphylaxis. 
  • The median time to onset of biphasic symptoms was 11 (range 0.2–72) hours, that is, 50% of reactions occurred >11 hours after initial reaction. Hence why all children should be admitted. 
  • Children and young people at risk of anaphylaxis should be referred to clinics with specialist competence in paediatric allergies. 
  • Children and young people who are at high risk of an anaphylactic reaction should carry an adrenaline auto-injector and receive training and support in its use.
  • They will need 2 auto-injectors – 20% require a second dose
  • Medic-alert bracelet and patient education
  • Further follow up – the most common way to diagnose an IgE-mediated allergy is through a blood test to identify allergen specific IgE or a skin prick test which results in a local inflammatory reaction after administration of the trigger allergen.
  • Oral food challenges – need to have appropriate resus facilities. 
  • AIT – Allergy immunotherapy or ‘Desensitisation’ works by changing the immune system’s response. These changes may include producing less IgE, producing ‘blocking’ IgG antibodies, and producing more regulatory T cells, promoting tolerance and a less active immune response. However, the exact mechanism behind desensitisation is not yet known and it is likely that different patients exhibit different immune profiles following the treatment. Only available for wasps, bees, dust mites and animal dander. Clinical trials for food allergies are on-going.

Can you administer IM adrenaline? (8 minutes)

A 6 year old patient with spina bifida is currently admitted with an LRTI. She has been having a course of amoxicillin for the last week. You are crash bleeped to the ward where she is having her urinary catheter changed by a bank nurse. She is pale and cool to touch, with increased respiratory rate.

What’s going on? Is this allergy? Is this anaphylaxis?

How would you treat it?

What allergy avoidance advice do you give?

  • Initial management: Observations and assess (BP)
  • Initial presentation of anaphylaxis – high safety margin for IM adrenaline
  • Hypotension as a warning sign (absence of a rash) – is it fluid responsive? May require large volumes of fluids. No evidence for crystalline vs colloid. Give 0.9% saline or Hartmanns. 
  • Explore medical history for triggers, explore unusual or uncommon triggers (e.g. exercise as a trigger, consider co-existing triggers e.g. prawns and exercise)

The following are risk factors for latex allergy:

  • Repeated bladder catheterisation 
  • Neural tube defects: Spina bifida 
  • Cloacal abnormalities 
  • Multiple surgical procedures, especially as a neonate 
  • Atopy and multiple allergies 
  • Food allergies: fruit and vegetables including bananas, celery, fig, chestnuts, avocados, papaya and passion fruit are most significant. 
  • Children with a strong or confirmed allergy to banana should be considered allergic to latex and managed accordingly.

The most common food trigger for fatal anaphylaxis in children in the UK is milk, followed by peanut and tree nuts.  While there is broad public recognition of the risks posed by nuts, cow’s milk allergy is often perceived as being less severe. However, milk allergy persisting into school age is often associated with other coexisting atopies (such as asthma) and more severe reactions, particularly in the 30%–40% of milk-allergic children who are unable to tolerate milk in well-baked foods (such as biscuits or cakes). Such exposure often results in delayed reactions which mimic asthma; under such circumstances, it may not be obvious that the child has been exposed to milk. Therefore, always consider anaphylaxis in someone with a known food allergy who has sudden breathing difficulty.

An 8 year old girl presents after collapsing following attendance at a friend’s birthday party. She was noted to have been eating a sandwich, then promptly developed respiratory distress. She has had two epipens with the ambulance crew, and a further dose in PED. You are called as senior support. Her sats are dropping and she is becoming bradycardic.

If the patient isn’t improving after IM adrenaline, what are your next management plans?

How do you prepare for intubation?

What do you do next?

  • Ensure the most senior people are present
  • Contact retrieval services early
  • How would you determine this? 
    • Airway obstruction/cardiovascular collapse
  • Who should be involved in the conversation? Who should perform the intubation?
    • Most senior anaesthetist, ideally with ENT support 
  • What do you do whilst prepping
    • Continue adrenaline – IM and nebulised whilst prepping for intubation
  • What sedation would you use?
    • Choose cardiovascular stable drugs – a drop in BP at this stage can precipitate cardiac arrest. Consider ketamine, fentanyl and rocuronium in 1:1:1 ratios. 
  • What equipment would you use?
    • Have advance and difficult airway trolley prepped and ready
  • What settings would you use?
    • Ventilate as for air trapping/bronchospasm
    • Pressure control (aim PIP <35 cm H2O)
    • Slow respiratory rate (e.g. 10-15 bpm)
    • Long expiratory time (e.g. I:E 1:2)
    • Permissive hypercapnia (aim pH >7.2)
    • PEEP 5 – 10 cm H2O to overcome intrinsic PEEP
    • Consider manual decompression
    • Muscle relax
  • Regular chest physiotherapy and suction for mucus plugging
  • Treat bronchospasm as per asthma guidelines (CATS or local)
  • Watch for pneumothoraces
  • Consider IV adrenaline infusion
  • Consider NaHCO3 for profound/refractory acidosis
  • Might need to escalate to IV adrenaline infusion – prescription calculation available on CATS website – ‘in a hurry’ drug chart (see appendix)
  • UK Resus council: No evidence to base a dose recommendation – the dose is titrated to response. Can titrate in presence of continued haemodynamic monitoring. Consider arterial line to enable continuous monitoring. 
  • A child may respond to a dose as small as 1microgram/kg. This requires very careful dilution and checking to prevent drug errors.

All adverse drug reactions should be reported to the Medicine and Healthcare products Regulatory Agency (MHRA) using the “Yellow Card” scheme (found in BNF and MIMS). 

The patient must be referred to an allergist in a defined Regional Allergy Centre. 

All fatal cases of suspected anaphylaxis should be discussed with the coroner.

What dose of adrenaline would you give to a 5 year old presenting in suspected anaphylactic shock?

A: 150 micrograms IM (0.15 mL) of 1:1000

B: 150 micrograms IM (0.15 mL) of 1:10000

C: 300 micrograms IV (0.15 mL) of 1:1000

D: 300 micrograms IM (0.15 mL) of 1:10000

The correct answer is A.

IM is always preferred in children owing to its broad safety profile. 1:1000 is the correct concentration. 1ml/kg of 1:10000 IV is the cardiac arrest dose. If the child does arrest then stop using IM and move to the standard APLS arrest dose as per protocol.

In order to diagnose anaphylaxis there must be a rash

A: True

B: False

The correct answer is false.

Cutaneous symptoms (most commonly urticaria or ‘hives’) are absent in around 10-20% of anaphylaxis reactions and where present may be delayed in onset. This is consistent with a case series of six paediatric fatalities due to food anaphylaxis, where only one child had evidence of skin involvement: the lack of skin signs may have delayed diagnosis and appropriate treatment with epinephrine, contributing to the fatal outcome.

The Australasian Society of Clinical Immunology and Allergy (ASCIA) recently issued new guidelines, which define anaphylaxis as:

  • Any acute onset illness with typical skin features (urticarial rash or erythema/flushing, and/or angio-oedema), PLUS involvement of respiratory and/or cardiovascular and/or persistent severe gastrointestinal symptoms; or
  • Any acute onset of hypotension or bronchospasm or upper airway obstruction where anaphylaxis is considered possible, even if typical skin features are not present.

These criteria better reflect increasing recognition that cutaneous manifestations are often absent or appear late in near-fatal and fatal anaphylaxis.

Antihistamines can be used to treat anaphylaxis initially; epinephrine is only needed if symptoms worsen

A: True

B: False

The correct answer is false.

Histamine is only one of many inflammatory mediators released during anaphylaxis. Oral antihistamines take around 30 min for onset of effect; intravenous chlorphenamine has a faster onset, but can cause hypotension. 

Antihistamines are not effective against anaphylaxis: their prophylactic use during controlled immunotherapy does not prevent anaphylaxis, and any apparent response during acute management of reactions is most likely due to the patient’s own endogenous epinephrine. Antihistamines have now been relegated to third-line therapy in international guidelines; their use is limited to the relief of cutaneous symptoms and should never delay the administration of epinephrine or fluid resuscitation during patient stabilisation.

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Bronchiolitis Module

Cite this article as:
Tessa Davis. Bronchiolitis Module, Don't Forget the Bubbles, 2020. Available at:
AuthorTessa Davis
DurationUp to 2 hours
Equipment requiredNone
  • Basics (10 mins)
  • Main session: (2 x 15 minute) case discussions covering the key points and evidence
  • Advanced session: (2 x 20 minutes) case discussions covering grey areas, diagnostic dilemmas; advanced management and escalation
  • Sim scenario (30-60 mins)
  • Quiz (10 mins)
  • Infographic sharing (5 mins): 5 take home learning points

We also recommend printing/sharing a copy of your local guideline.

A 7 month old infant presents on Day 4 of the illness. He has mild to moderate work of breathing. Sats 95% in air. He is taking around half his normal feeds.

What investigations and treatment options should you consider?

Why doesn’t salbutamol work in this age group?

How do you know when to admit?

See the PREDICT systematic review of all treatments

  • Salbutamol – there is no benefit in using salbutamol in infants with bronchiolitis (and some evidence of adverse effects)
  • Nebulised adrenaline – no clinically useful benefit (there is evidence for temporary effect but not for improvement in outcome)
  • Nebulised hypertonic saline – there is weak evidence of a reduction in length of stay of 0.45 days. However when two studies were removed, both of which used a different discharge criteria than most hospitals, there was no benefit. This is not recommended routinely, although the authors suggest that it should be used only as part of an RCT
  • Glucocorticoids – no benefit
  • Antibiotics – not recommended (The risk of a secondary bacterial infection is very low, and there is potential harm from giving antibiotics)
  • Oxygen – no evidence of benefit in infants with no hypoxia, and low level evidence that maintaining the sats over 91% with oxygen actually prolongs the length of stay. There are no reports of long-term adverse neurodevelopmental outcomes in infants with bronchiolitis, however there is also no data on the safety of targeting sats <92%. Commence oxygen therapy to maintain sats over 91%.
  • Sats monitoring – there is moderate evidence suggesting that continuous sats monitoring increases the length of stay in stable infants
  • High flow – there is low to very-low level evidence of benefit with high flow
  • Chest physiotherapy – not recommended
  • Saline drops – routine saline drops are not recommended but a trial with feeds may help
  • Feeds – both NG and IV are acceptable routes for hydration

See Beta receptor mythbusting (from

A 6 month old infant presents on Day 3 of the illness. She has moderate to severe work of breathing. Sats are 91% in air. She is struggling to feed at home.

What management options would you consider?

See the PARIS Paper

This is the biggest and most robust trial yet done to assess the value of high-flow in bronchiolitis. The primary outcome shows that there is a role for high-flow in the non-ICU management of this disease. Importantly PARIS has shown in a large cohort of children that high-flow, when used within the parameters of the trial protocol, does not lead to an increase in adverse events which in-turn suggests the increased patient:nurse ratios for kids on high-flow that are often mandated by hospital policies may not be necessary (depending on the severity of disease of course). Some caution must be used around the potential for erroneous use of the high-flow circuits themselves and the interpretation of early warning scores in the context of high-flow use.

PARIS was supported with significant nursing education resources potentially reducing errors to a level that were below what could be expected with the standard resourcing of mixed EDs and other environments where high-flow use in children may be infrequent. As with many grey areas in medicine protocols as to how we use high-flow vary by institution with little more than opinion to guide them.

Though neither the intention nor the conclusion of this paper in showing the progress of such a large number of children on high-flow, this trial also provides a basis for more robust decision making around how we use high-flow itself.

NICE feeding guidance

  • Give fluids by nasogastric or orogastric tube in children with bronchiolitis if they cannot take enough fluid by mouth.
  • Give intravenous isotonic fluids (see the NICE guideline on intravenous fluids therapy in children) to children who: do not tolerate nasogastric or orogastric fluids; or have impending respiratory failure.

Do you know how to set up high flow? (8 minutes)

How to set up Airvo 2 (Optiflow)  (3.5mins)

How to use Airvo 2 (6 mins)

You have a 12 month old, with two days of coryza and one day of increased work of breathing symptoms.

How do you manage them?

How do you figure out whether they have bronchiolitis or VIW?

Practically speaking, we know that bronchiolitis and viral induced wheeze have two quite different management pathways, but it is not as if a child moves from being 12 months old to 13 months old and therefore cannot have bronchiolitis (or vice versa for viral induced wheeze). These conditions as previously mentioned, exist on a spectrum. 

  • What has been the onset of symptoms? Progressive over days is most consistent with bronchiolitis. Onset of wheeze and respiratory distress over hours is most consistent with bronchospasm (viral induced wheeze).
  • What has been the pattern of their work of breathing? 
  • How significant is the work of breathing? 
  • What are the auscultation findings – is there presence of focal findings? Wheeze? Crackles? 
  • Is this affecting the child functionally with feeding or sleeping difficulties?
  • If auscultation is suggestive of possible viral induced wheeze or at least, a component of wheeze that may be responsive to bronchodilators (If wheeze is present and no crackles or focal findings) and presuming the child has more than just mild work of breathing -then we suggest this may be a possible candidate for viral induced wheeze.  
  • (Note – This is a good opportunity to survey your team and colleagues to see what the practice is at your local department). 
  • Regarding this grey area question, in Australian practice, some clinicians will trial salbutamol for potential viral induced wheeze if the child is 12 months or older. Other doctors may wish to trial if the child is slightly younger (e.g. from 10 months) if they have a strong family history of asthma and atopy or if they have had previous ventolin use reported by their family with good effect. The younger the child is, the less likely that the story and case is to fit viral induced wheeze.

It would be prudent to give 6 puffs (or do you use another number?) and reassess following to see if there is any improvement or change.

You’ve started high flow 2L/kg for a four month old with bronchiolitis, moderate work of breathing and saturations of 88% and titrated FiO2 up to 30% to maintain saturations. However they are still intermittently desaturating so you titrate them up to 40% FiO2.

They have ongoing work of breathing with a respiratory rate of 60-70.

What are your next steps?

Consider revisiting history, respiratory examination and consider adjuncts to assessment such as a capillary or venous blood gas.

  • For example, Do they have an NG tube on free drainage, are they nil by mouth and on IV fluid support at ⅔ maintenance
  • Are their family actually compliant with this or have also been feeding them via a bottle? 
  • Are they working harder to breathe because they are getting “hangry” and might actually tolerate a continuous NG or comfort feed?
  • Consider whether the HFNP has led to no change, improvement and then deterioration or simple worsening of symptoms due to patient distress.
  •  If no improvement was observed on commencement – it may be worth de-escalating them – ie. lower flow rates or low flow nasal prongs

Consider your confidence of whether you have the right diagnosis or if there is need to assess for a secondary pathology such as pneumonia, foreign body, cardiac contribution? Do you need to further investigate with bloods, CXR? Do you need to append your management and provide antibiotic coverage? Do you need to assess for a complication from treatment e.g. pneumothorax.

  • Have you sought a senior review/notified the admitting paediatrician?
  • Do you need an ICU consult, NETS consult or retrieval to a tertiary centre?
  • How long are you comfortable to wait to see if there is a response to high flow?
  • What settings would you start on?
  • Where could you move up to (in terms of peep, FiO2)
  • How soon would you reassess – what are you looking for?

  • How would you determine this?
  • Who should be involved in the conversation? Who should perform the intubation?
  • What sedation would you use?
  • What equipment would you use?
  • What settings would you use?

In bronchiolitis, children do not respond to salbutamol because:

A: They don’t have beta receptors until they are older.

B: The beta receptors are immature and do not begin functioning correctly until the child is older.

C: The large amount of secretions interfere with it and prevent it binding to the receptors

D: There is no bronchospasm for the salbutamol to act on.

The correct answer is D.

All humans have beta receptors. Foetuses develop them from around 15 weeks gestation and are therefore born with them. Developing beta receptors after 1 year of age is a common paediatric myth! In fact, in bronchiolitis, there is no bronchospasm in the same way as there is in viral induced wheeze. Bronchiolitis is a illness developing gradually over 4 days and then slowly improving. Patients have increased mucous rather than bronchospasm, which does not respond to a bronchodilator.

A 3 month old baby presents to ED with coryza, cough, and poor feeding. Breastfeeding is going ok, but the baby is feeding for shorter periods, more frequently than usual. She is having wet nappies as normal. Saturations are 93% on room air, RR is 62, and there is moderate subcostal recession with some nasal flaring. Which of the following is an indication to admit this baby to hospital?

A: The reduced breastfeeding

B: The oxygen sats

C: The work of breathing

D: The age of the baby

The correct answer is C.

The criteria for admission usually are:

  • feeding less than half of usual, or less wet nappies
  • saturations less than 92% on air
  • increased WOB
  • apnoeic episodes

Risk factors such as:

  • Ex-prem
  • Age less than 12 weeks or less than 37 weeks CGA
  • history of lung disease or congenital heart disease or neurological problems
  • smoke exposure

In clinical practice, you would use your judgement to assess if hospitalisation was necessary. Social concerns should always be considered.

In this case, the baby is maintaining good urine output and the feeds, although shorter, are more frequent. The age alone is not an indication for admission. Obviously, an O2 requirement would be an indication for admission but most units would consider sats of 92% or less as reduced. There is significantly increased work of breathing with recession and nasal flaring, however, so this would be the main indication for admission.

You have a 10 month old baby with bronchiolitis who is to be commenced on high flow. Which of the following is false?

A: Nasal prongs size should be estimated based on the width of the patient’s nostrils.

B: Patients can be NG fed immediately once on high flow. 

C: High flow improves the functional residual capacity.

D: The humidified oxygen help clearing mucous secretions.

The correct answer is B.

Patients on high flow will likely need an NG inserted due to abdominal distention, but should usually not be fed for the first couple of hours on high flow. The aim of high flow is to provide humidified, high flow to improve clearance of secretions and to increase the functional residual capacity. Together this should reduce the work of breathing.

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