Paediatric analgesia and pain assessment

Jamie is a 3-year-old boy who presents to the emergency department. He was playing with his 5-year-old brother on the trampoline and fell off. He is very distressed and crying in triage but his mum doesn’t know where he hurt himself. She had rushed to the department with him and so hadn’t given him any prehospital analgesia. Mum herself also appears very anxious and worried.

Pain assessment and management in the paediatric population is a challenging area, and it is something that we often get wrong. Children’s pain is historically poorly measured and often under-treated because children may not exhibit the common signs and symptoms of pain that we come to expect from adults.

Pain is multifactorial. In children, it is important to not just focus on the injury but the age and developmental stage of the child, the circumstances of the presentation to ED, the behaviour of the parent/caregiver and the child’s interaction with them.

In the case of James, his mum appears very anxious about his injury. Children tend to feed off of their parent’s anxiety and become more distressed. Moving them to a quiet area for assessment and reassuring mum that they are in the right place and that you’re going to take great care of James is an ideal starting point. Hopefully, reassuring and calming his mum will go some way to diffusing the situation, and calming James also.

Pain assessment

Assessment of a child in pain varies greatly with their age and developmental stage. This is one of the most important things to take into account during your encounter. If the wrong tool is used, the pain may be underestimated and the child under-treated. The longer the time to proper pain relief, the more distress there is for both child and parent, and so the spiral continues.

Neonates and infants (0 – 2 years)

For the youngest, the FLACC (Faces, Legs, Arms, Cry, Consolability) scale can be useful. This scale comprises five components. The child needs to be observed for at least a minute. A child of this age isn’t going to be able to tell you much about their pain, so you need to rely heavily on your observational skills. Involving the parent in the assessment is key.

Context is very important in this group also, particularly for the one-year-old who seems very distressed in triage or when being examined by the strange doctor but is more settled in mum’s lap. Frequent reassessments are therefore extremely important and beneficial.

Toddlers and preschoolers (2 – 4 years)

In this group, developing a rapport is a must in order to be able to accurately assess the level of pain. Get on the child’s level, use a soothing friendly voice, employ some ice-breaking chat.

Ask open-ended questions, don’t just palpate areas and say “Does this hurt?” – as you may well get a yes in every area – e.g. “Can you show me where is sore? Can you point to what is hurting you?”

For these slightly older children, the Wong-Baker faces scale is great. These can be produced in bright colours to make them fun  and to aid with their participation in the assessment.

This scale has been validated in children aged 3 and up, but in practice it is often used in those over 2. The child is shown the faces and asked to point to the one that best represents how they are feeling.

Again, reassessment after initial analgesia using the same scale/method of assessment is important.

School-aged children (4 – 16 years)

As the child develops verbally, the assessment of their pain should become easier. For children aged 4-8  years of age, the Wong-Baker faces scale is probably still the most appropriate tool to use. In the older child, you can use the numerical pain ladder.

This can be either a visual representation where you ask them to draw a line or indicate where their pain falls on a physical scale, or you can simply ask them to give their pain a score out of 10 without showing them the scale.

You move James and his mum to the minors area to complete his assessment. Mum is now calmer, and this seems to have settled James somewhat. He is no longer crying, but he is still grimacing and he appears to be holding his left elbow fixed in flexion. You ask him point to where it is sore and he indicates his left arm. He refuses to move it. A survey of the rest of his body doesn’t reveal anything else concerning, he is fully weight-bearing and is moving his neck and right arm without issue. On palpation and careful examination of the left arm he is very distressed when his elbow is touched, and it appears to be swollen. You show him the Wong-Baker scale and he points to the orange sad face, which indicates a pain score of 8.

Pain management

To achieve the best pain management for our patients, we first have to have a basic grasp of pain physiology.

Nocioceptive pain follows a sequence where 4 events take place:

Pain transduction – a painful stimulus eg trauma causes tissue damage – this leads to the release of chemical mediators in the tissue, e.g. prostaglandins/substance P etc. These trigger an action potential.

Transmission – the action potential moves along the nerve fibres, travelling from the peripheral site of injury to the spinal cord.

Perception – the action potential travels along the spinothalamic tract to the brain, where it is relayed to the areas involved in pain perception (limbic system, somatosensory cortex, parietal and frontal lobes)

Modulation – the midbrain releases endorphins/serotonin etc to mitigate pain

We can target each part of the sequence in our treatment of pain, as long as we remember that analgesia is multi-modal, and does not just revolve around drugs.

Transduction

We can intervene at this stage by employing basic first aid measures – for example

• If the child has a burn – run it under cool/room temperature water. This will provide pain relief as well as arresting further tissue damage
• If a limb is obviously deformed or clinically has a fracture – splint or backslab the limb during your initial assessment and before sending the child for x-rays
• If there is a suspicion of a clavicular or shoulder injury give the child a sling
• If they have a swollen area ?soft tissue injury e.g. ankle – place an ice pack and get them to elevate the ankle.

These things may seem like common sense, but all too often they are forgotten in favour of pharmacological interventions which will not have as immediate an effect.

Perception

A child can be distracted much more easily than an adult, and we need to use this to our advantage in the context of pain management. Employing distraction techniques can affect and reduce a child’s perception of pain.

There are many options available and you can get the parents involved also. Distraction techniques obviously vary in their effectiveness depending on the age of the child, but they include: story-telling; singing a song (I can’t be the only one that hears Baby Shark as they fall asleep at this point!); balloons; stickers; bubbles; playing a video on a smartphone.

For older children, guided imagination can be used to great effect, particularly before procedural sedation with nitrous oxide or ketamine. Letting them listen to their own music on their phone via earphones is also a good idea. Some departments are now looking at the role of virtual reality headsets for older children undergoing painful procedures which appears to be a very successful method of distraction.

Transmission

Pharmacological agents act to interrupt the transmission of the painful stimulus. There are many agents available, depending on the child’s age and the level of pain described.

Topical anesthetics

Ametop (4% w/w Tetracaine) and EMLA 5% (lidocaine/prilocaine) are anaesthetic creams that can be applied to intact skin, usually pre-cannulation. They numb the skin and make the procedure less painful. They are ideal in situations where a slight delay to cannulation is safe, as they need to be in situ for a while to work (Ametop 30 mins, EMLA for an hour).

LAT gel – Lignocaine 4% / Tetracaine 0.5% / Adrenaline 0.1% is an anaesthetic gel. It comes in a single-use bottle. It is designed for use on broken skin, and so it should be ideally applied to wounds/lacerations in triage and left in situ for 30. It numbs the area and allows for thorough cleaning, proper assessment, and closure of wounds while reducing the need for injectable local anaesthetic in a lot of cases.

Contraindications

• ANY previous reaction to local/ general anaesthetic or known cholinesterase deficiency
• Wound on or near mucus membrane including eye, nose or mouth.
• Wound > 5 cm in length
• Concern about tissue viability i.e. crush or flap wounds
• Wounds over 8 hours old
• Obvious injury to associated structures i.e. bone, tendon, blood vessels, joint or nerve
• Wounds to the ear, nose, genitalia or digits should be discussed with a registrar before using LAT gel. This is due to concerns about perfusion and also due to evidence showing less effect on extremity wounds.

Paracetamol

This is perhaps best known to parents as Calpol (UK and Ireland), Panadol or Crocin (Australia) or Tylenol (in the States), however, there are other brand names. There are two different preparations of Calpol depending on age (120mg/ 5mls or 250mg/5mls) so make sure to clarify what the parent has at home.

Paracetamol can be given PO/PR/IV but is most commonly given orally. The dose is 15mg/kg to a maximum dose of 1 g.

It can be given 4-6 hourly, but to a maximum of 4 doses in 24 hours. It takes approximately 30 minutes to work

Overdose is 75mg/kg (although toxicity usually doesn’t occur until >150mg/kg in an acute ingestion or repeated supra therapeutic doses>100mg/kg). If this happens it can cause hepatic necrosis – so bloods will need to be checked and if the paracetamol level is beyond a certain threshold the child will need to be started on n-acetyl cysteine.

Ibuprofen

Ibuprofen is a non-steroidal anti-inflammatory (NSAID) that is available over the counter. NSAIDs work to stop the inflammatory cascade of chemical mediators and thus reduce inflammation and pain. It is also an anti-pyretic.

It is commonly sold as Nurofen (in the UK, Ireland and Australia) and Advil (in America) but again has other brand names as well as being sold by generic name. Nurofen also comes in two preparations (100mg/5mls or 200mg/5mls) – always clarify with the parents as to what they have at home to ensure appropriate dosing.

Ibuprofen can be given at a dose of 10mg/kg to a max of 400mg 8 hourly. An overdose obviously isn’t desirable but does not carry the same dangers as paracetamol.

It can be given PO or PR, however the suppositories only come in 60mg so are not as useful in bigger children.

Always, always double-check which medicine a parent may have given at home. For example, Calpol contains paracetamol but Calprofen contains ibuprofen – you can see how double doses can accidentally be given in the emergency department soon after a child presents.

Diclofenac

Diclofenac also a member of the NSAID family. It can be used in place of ibuprofen in the older child in its oral form.

In my own practice PR diclofenac suppositories have been invaluable in the pain management of infants with stomatitis or bad tonsillitis causing distress and poor oral intake, while also controlling their pyrexia.

The dose is 1mg/kg 8 hourly (max 50mg per dose) and can be given PO/PR.

Max dose is 3mg/kg in 24 hours.

Morphine

Morphine is a strong natural opioid. It is used for severe pain, or pain that is not responding to first-line analgesics. It can be given by a variety of routes, but most commonly PO or IV.

Oramorph is an oral form of morphine, available in liquid preparation and is dosed by age band:

• <1 year: 80 -200mcg/kg
• 1-2 years:200-400mcg/kg
• 2-12 years:200-500mcg/kg
• 12-18 years: 10-15mg

Its IV dose is 0.1mg/kg. It can be given prn usually every 4-6 hours

Potentially serious side effects include decreased respiratory effort and low blood pressure. Overdose treatment includes the administration of naloxone (0.1mg/kg IM or IV).

Fentanyl

Fentanyl is a strong synthetic opioid with a faster onset / offset than morphine, starts to work within 7 minutes. It’s great for initial analgesia for fractures/dislocations, burns, major lacerations.

The loading dose is 1.5mcg/kg and can be repeated after 20-30 minutes

Side effects are uncommon, but may include respiratory depression/hypotension/nausea and vomiting. It is given intranasally (IN) with an atomizer device and has great mucosal uptake without having the need for IV access.

Diamorphine

Diamorphine is also an opioid that can be given intranasally as an alternative to fentanyl, using an atomizer device.

The dose is 0.1mg/kg IN

It carries the same potential side effects as morphine and fentanyl, but has been shown to be very safe at this dose in the paediatric population.

Methoxyflurane

Methyoxyflurane is also known as Penthrox / the green whistleIt is an inhaled medication primarily used to improve pain following trauma. Each dose lasts approximately 30 minutes.

Pain relief begins after 6–8 breaths and continues for several minutes after stopping inhalation

It is self-administered to children and adults using a hand-held inhaler device

The STOP trial looked at its safety and efficacy in adults and children >12 and found that it was safe and worked well. It is currently being investigated in those aged 6-18 in the MAGPIE trial, which is still undergoing data collection.

Procedural sedation

Sometimes, analgesia alone isn’t enough. If a child has a deformed fracture for example that needs to be manipulated, they will need procedural sedation. This is usually achieved with wither nitrous oxide or ketamine, depending on the child’s age and the procedure required.

References

Srouji R, Ratnapalan S, Schneeweiss. Pain in Children: Assessment and Nonpharmacological Management. International Journal of Pediatrics. 2010. doi:10.1155/2010/474838

https://pemplaybook.org/podcast/pediatric-pain/

Manwarren R and Hynan L. Clinical Validation of FLACC: Preverbal patient pain scale. Pediatric Nursing. 2003; 29(2):140-6

Keck JF et al. Reliability and validity of the Faces and Word Descriptor Scales to measure procedural pain. J Pediatr Nurs. 1996;11(6):368-741996

Tomlinson D et al. A systematic review of faces scales for the self-report of pain intensity in children. Pediatrics. 2010;126(5):e1168-98. doi: 10.1542/peds.2010-1609

Horeczko T. “Acute Pain in Children”. In Management of Pain and Procedural Sedation in Acute Care. Strayer R, Motov S, Nelson L (eds). 2017.  

Knight K, McClenaghan CE, Singh B: Virtual reality distraction from painful procedures in the paediatric emergency departmentArchives of Disease in Childhood 2019;104:204-205.

Leicester Children’s Hospital clinical guideline. Use of Topical Wound Anaesthetic- LAT gel in the PED. Rowlands. Feb 2014.  https://static1.squarespace.com/static/546e1217e4b093626abfbae7/t/59cba0aa12abd9d55c449106/1506517164347/Topical+Wound+Anaesthetic+-+LAT+Gel+UHL+Paediatric+Emergency+Guideline.pdf

Royal Children’s Hospital Melbourne clinical guideline. Management of paediatric paracetamol overdose. https://www.rch.org.au/clinicalguide/guideline_index/Paracetamol_poisoning/

Sharif MR et al. Rectal Diclofenac Versus Rectal Paracetamol: Comparison of Antipyretic Effectiveness in Children. Iran Red Crescent Med J. 2016;18(1): e27932

Kendall J, Maconochie I, Wong ICK, et al; A novel multipatient intranasal diamorphine spray for use in acute pain in children: pharmacovigilance data from an observational study. Emerg Med J 2015;32:269-273.

Coffey F, Wright J, Hartshorn S, et al: STOP!: a randomised, double-blind, placebo-controlled study of the efficacy and safety of methoxyflurane for the treatment of acute pain. Emerg Med J 2014;31:613-618.