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The 75th BUBBLE WRAP X Sheffield Children’s Hospital Emergency Department


With millions upon millions of journal articles published yearly, it is impossible to keep up.  This month, Bubble Wrap has teamed up with Sheffield Children’s Hospital Emergency Department to have a look at what’s new in paediatric literature.

Sheffield Children’s Hospital is a stand-alone tertiary children’s hospital in the heart of Sheffield with a paediatric MTC. The Emergency Department team is a fab and friendly mix of Emergency Medicine and paediatric folk with shared interests in giving the best care to their patients and eating cake.   

Article 1: Do you have the right endotracheal tube?

Ebenebe CU, Schriever K, Apostolidou S, et al. Recommendations for endotracheal tube insertion depths in children. Emergency Medicine Journal 2023;40:583-587.

What’s it about? 

Precise placement of endotracheal tubes (ETT) can reduce the complications associated with intubation, e.g. pneumothorax and atelectasis. Though the gold standard for evaluating the placement of ETTs is a chest X-ray (CXR), we often rely on formulas (of which there are many) to estimate the correct depth.

This study compared age, weight and height-based recommendations for ETT depth for children over 28 days (as their guidelines stipulate that those under this age must be intubated using a nasotracheal route). Two evaluators used CXRs to retrospectively evaluate the distance between the ETT tip and the carina and looked at demographics such as sex, age, weight, height and intubation route.  The optimum ETT to carina distance was compared to age-appropriate standards. They excluded patients with airway anomalies and those with tracheostomies.

Using the information from 167 intubated patients (ages ranging from 0 – 17.9 years) in an intensive care setting in Germany, they used four-parameter logistic regression analysis to develop the best-fit curve to plot the ETT to carina distance compared to demographics such as age, weight or height.

Overall, height-based formulas resulted in more accurate ETT placement. However, these formulas are not linear and are only reliable during a limited period of the child’s growth. Using these formulas universally can lead to significant malposition rates. As such, they developed their table of suggested ETT depths based on height, recognising that their recommendations require future validation. They do not replace CXRs as the gold standard.

The height of the patients was measured in the PICU using a Broselow tape. This is not always feasible in an acute resuscitation scenario.

For a deeper look into intubation in the critically unwell child, check out Vicki Currie’s article: Intubation of the critically unwell child in the emergency department – Don’t Forget the Bubbles (

Why does it matter? 

Both APLS and EPALS use weight as the basis of the ETT depth formula, but this study demonstrates how these formulas are unreliable.

We can often eyeball a patient and judge whether their weight correlates to the WETFLAG formulas, though we could use a more accurate and reliable table to estimate ETT. This would be preferable if we are waiting for CXRs to confirm the position.

Clinically Relevant Bottom Line:

Using age as the basis for EPALS/APLS formulas for ETT insertion depth is unreliable. It assumes a linear relationship between weight and height. This group has developed a height-based guide for ETT insertion but recognises that measuring a patient’s height may not be feasible within an ED setting.

Reviewed by: Dr Lucine Nahabedian

Article 2: Is lactate a helpful screening tool?

Nygaard U, Dungu KH, von Linstow ML, Lundstrøm K, Zhang H, Vissing NH. Lactate as a screening tool for critical illness in a pediatric emergency department. Pediatric Emergency Care. 2023 Oct 1;39(10):735-8.

What’s it about? 

This retrospective observational cohort study examined whether lactate can predict the need for acute resuscitation in paediatric emergency department (PED) patients.

The study included all patients (aged 0-17 years) admitted to Copenhagen University Hospital’s PED between 1st Jan 2019 and 1 Jan 2021. Patients were included if they had lactate measured as part of their acute PED evaluation.

Lactate levels were reported separately in several sets of patients:

1) Those who needed acute resuscitation (fluid bolus of 20 mL/kg or more, respiratory support with oxygen saturation less than 90%, and/or cases referred to PICU)

2) Those who did not need acute resuscitation

3) Those with samples taken after inhalation of salbutamol

A total of 1355 children were included. 14 children (1%) needed acute resuscitation, 1314 children didn’t need acute resuscitation, and 27 children had lactate measurements after inhaled beta-2-agonists.

There was no difference in lactate levels in children who received acute resuscitation compared with those who did not (median lactate 1.7 mmol/L vs 1.6 mmol/L; P > 0.05). Acute resuscitation was not more frequently required in children with lactate greater than 4 mmol/L compared to children with lactate of less than 4 mmol/L (1 of 28 [3.6%] vs 13 of 1341 [1.0%]; P > 0.05).

In children who did not need acute resuscitation, the 95th percentile of lactate was 3.2 mmol/L, and 392 (28.9%) had a lactate greater than 2.0 mmol/L.

Older age and venous sampling were associated with lower lactate. Lactate was not associated with sex, PEWS, or duration of hospital admission.

The 95th percentile for lactate after inhaled beta-2-agonist was 5.0 mmol/L, with a 2.6 mmol/L median. They had significantly higher lactates than the cohort of children with acute illness without acute resuscitation (P < 0.001).

For more about lactate, see the post on DFTB:Blood Lactate: Freshly Squeezed – Don’t Forget the Bubbles (

Why does it matter? 

The early recognition of critical illness is essential in reducing morbidity and mortality, but these children frequently present with initially subtle signs and symptoms.

Multiple tools, including Paediatric Early Warning Scores (PEWS), have been introduced to improve the ability to identify unwell children and those at risk of deterioration. Within some paediatric emergency departments, serum lactate is now used as a critical illness screening tool. It is, therefore, essential for us to know how accurate and reliable a measure this is.

Clinically Relevant Bottom Line:

This study does not support the routine use of lactate as a screening tool.

In addition, the reported 95th percentile lactate of 3.2mmol/L in children not needing acute resuscitation is considerably higher than the generally recognised acceptable cut-off level of 2.0mmol/L. This is important and should help prevent excess concern in patients who are otherwise clinically stable.

Based on this study, we should be very cautious in using lactate as a screening tool for the early recognition of critical illness in PED. 

Reviewed by: Dr Lizzie Binham

Article 3: Does early administration of IV magnesium result in fewer PICU admissions for patients with severe asthma?

Forster, B, Thomas, F, Arnold, S et al. Early Intravenous Magnesium Sulfate Administration in the Emergency Department for Severe Asthma Exacerbations. Pediatric Emergency Care 39(7):p 524-529, July 2023. DOI: 10.1097/PEC.0000000000002890

What’s it all about?

This retrospective study, conducted between 2016 and 2018, looked at paediatric patients aged between 2 and 17 years presenting with severe asthma exacerbation in a single tertiary paediatric Emergency Department in Memphis, Tennessee. They aimed to determine whether early administration of intravenous magnesium sulphate (within 60 minutes of registration) resulted in fewer PICU admissions.

Patients were divided into three groups based on asthma severity at the time of treatment: RCS (Respiratory Clinical Score) of 1-4 considered mild, 5-8 moderate and 9-12 severe. Patients were managed as per their institutional asthma pathway.

All patients with mild and moderate exacerbations receive salbutamol and oral steroids (dexamethasone) in that pathway. Those presenting with severe exacerbation receive IV salbutamol. Other medications, such as IV magnesium, were then given at the treating physician’s discretion. If the patient still required continuous nebulised salbutamol, they were referred to the PICU for admission.

A total of 1911 patients were included in the study, of which 1541 received IV magnesium sulphate with an average time of 79 minutes. 659 received it within 60 minutes of arrival, 882 received it after 60 minutes of arrival, and 370 received no IV Mg. Of the patients receiving IV Mg within 60 minutes, 124 were admitted to PICU. Of those receiving it after 60 minutes, 101 were admitted.

Timing of IV Mg administration was not associated with admission to PICU in patients with severe asthma exacerbation. Multiple independent factors were associated with admission, including diagnosis of status asthmaticus, arrival via ambulance, medication taken at home before arrival, previous PICU admissions and an RCS score of 10-12 compared to a score of 9.

Multiple interventions co-occur in the most severe patients, and it is difficult to attribute clinical improvement or reduction in PICU admission rates to IV Mg alone. However, when accounting for several confounding factors, administration of IV Mg (irrespective of when it was given) was associated with an increased likelihood of admission to PICU.

For more information on the management of asthma, see DFTB module: Asthma Module – Don’t Forget the Bubbles (

Why does it matter?

This study strengthens the recommendation in a 2021 Cochrane review casting doubt on the effectiveness of IV Mg in severe asthma exacerbations. However, there are limitations as this study is retrospective in design and observational rather than a randomised controlled trial. There were likely unmeasured confounders of associations between IV Mg and PICU admissions.

The Bottom Line:

Early administration of intravenous magnesium sulphate in severe asthma exacerbation does not result in fewer PICU admissions.

Reviewed by: Leanne Lindenstruth, ENP

Article 4: Can we treat appendicitis non-operatively?

Picard C, Abbo O, Munzer C, et al. Non-operative treatment of acute appendicitis in children: clinical efficacy of amoxicillin-clavulanic acid in a retrospective single-centre study. BMJ Paediatrics Open 2023;7:e001855. doi: 10.1136/bmjpo-2023-001855

What’s it about?

This retrospective, cross-sectional single-centre study looked at non-operative therapy (NOT), using co-amoxiclav, for acute uncomplicated appendicitis (AUA) at The Children’s Hospital of Toulouse, France. There was no control group.

104 children met these criteria:

  1. Abdominal pain, first episode of appendicitis.
  2. Age 5-15 years (children <5 often present late, unreliably and with complications).
  3. No CT or ultrasound evidence of complications (including appendicolith, perforation, abscess or peritonitis).
  4. No diagnosis of sepsis (defined as ‘good general condition, normal haemodynamic status, normal diuresis’).

Since 2014, the study centre has used NOT for AUA with 7 days of antibiotics at 80mg/kg/day, with two days of initial inpatient intravenous therapy, then switched to oral antibiotics.

The hypothesised 2-year success rate of NOT in paediatric AUA was over 80%. The initial study success rate was 100% and was assessed two weeks after discharge with an ultrasound and CRP. (CRP <5 IN 97% of patients at follow-up, US pathological in 9%).

Although some patients had abnormal ultrasound features at this follow-up, there was no significant link between this and appendicitis recurrence.

The 2-year success rate was 85.6% (89/104 patients), and no patients with recurrence of appendicitis presented with complications.

Check out: Appendectomy or antibiotics? – Don’t Forget the Bubbles (

Why does it matter?

Acute appendicitis is typically treated with surgery, however 5-15% of patients have post-operative complications. Between 1-40% of appendicectomies remove a non-infected appendix, i.e. were these surgeries unnecessary, and/or is there an alternative cause for symptoms?

NOT has previously been used successfully where resources are scarce, e.g. soldiers, submariners, or when there is a high risk of surgical complications, e.g. pregnancy.

The bottom line

In a larger multi-centre UK observational study (‘CASCADE’, Bethell et al., 2023), the success rate of NOT was 63.1%. However, surgery remains the mainstay of treatment of appendicitis in the UK remains surgery, and pre-operative clinical risk scores can be used to support decision-making. Further larger multi-centre studies are currently underway, which could add further weight to the fact that NOT is a safe treatment option for AUA.

Reviewed by: Dr Sarah Foster

Article 5: Do parents safely make up infant formula?

Grant A, Jones S, Sibson V et al. The safety of at home powdered infant formula preparation: A community science project. Matern Child Nutr. 2023;e13567

What’s it about?

This study assessed the water temperature used to make powdered infant formula (PIF) with either a kettle or a PIF machine that produces a ‘hot shot’. It used community science – recruiting members of the public on a Facebook group to assist in the recruitment of other parents of infants <12 months who are fed formula. Four community members were included as authors. Parents collected results using home thermometers to measure the temperature of an extra pour from the kettle or ‘hot shot’ from the PIF machine to ensure thermometers weren’t inserted into PIF that was then fed to infants.

200 UK‐based parents of infants aged ≤12 months were recruited; 151 provided data on PIF preparation, and 143 were included in the analysis of water temperatures used to reconstitute PIF. Only 14.9% (n = 11) of 74 PIF preparation machines produced a water temperature of ≥70°C compared with 78.3% (n = 54) of 69 kettle users (p < 0.001).

 The mean water temperature dispensed by PIF preparation machines was 9°C lower than kettles (Machine M = 65.78°C, Kettle M = 75.29°C).

Results also found that participants did not routinely follow all of the advice regarding sterilisation, timing and reconstitution methods. Many reasons were given, including difficulty finding information and advice changing too frequently, especially when it changed between the birth of one child and the next in a family.

The participants had higher than average education levels, and the general population may struggle with differing advice on formula make-up and the associated risks. Simplifying access to this advice could reduce infection rates. Including this advice on discharge of patients who are utilising PIF and present with diarrhoea or vomiting could also present an opportunity to reduce infection rates.

Using social media to recruit other participants and including some of them as authors is interesting and novel. Could this be utilised more in the future?

There was no standardisation of thermometers used, and there is likely to have been variation in the quality of the home thermometers.

For all things infant feeding, check out: How much do babies feed? – Don’t Forget the Bubbles (

Why does it matter?

NHS advice is that powdered infant formula should be reconstituted at a minimum of 70 degrees Centigrade due to potential bacterial contamination of the powder. The suggested method is to heat >1L water in a kettle and pour it within 30 minutes to make up the PIF. The NHS advice does not include using a PIF machine; however, half of the participants used one at least some of the time.

If powdered infant formula is reconstituted at lower temperatures, there is a risk of gastrointestinal infection from bacterial contamination. Some of these infections may be significant.

Clinically Relevant Bottom Line:

Lack of understanding around the reconstitution of formula can lead to an increased risk of GI infection. Advice should be readily available online.

Reviewed by: Dr Emma Faragher

If we have missed out on something useful or you think other articles are worth sharing, please add them in the comments!

That’s it for this month. Many thanks to our reviewers who have taken the time to scour the literature, so you don’t have to.

All articles reviewed and edited by Vicki Currie.


  • Vicki is a Paediatric Registrar in the West Midlands in the UK , starting PEM in September 2021. Vicki is passionate about good communication in teams and with patients along with teaching at undergraduate and postgraduate level. When not editing Bubble wrap Vicki can be found running with her cocker spaniel Scramble or endlessly chatting with friends.


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