Paediatric advanced life support

A 15 kg two-year-old boy is being anaesthetised, spontaneously breathing on a laryngeal

mask airway, for exploration and repair of a small umbilical hernia. The child is

otherwise fit and well. Thirty minutes into the procedure, for no apparent reason, the

child develops a bradycardia of 30bpm and end-tidal CO2 falls to zero. With regard to

the choice of uncuffed endotracheal tube (internal diameter in mm) for initial intubation

attempt, the bolus dose of intravenous adrenaline, and setting for the manual

monophasic defibrillator, which of the following options describes the BEST practice?

a) 4.0 endotracheal tube, 300 mcg adrenaline, defibrillator set to 30 joules

b) 4.5 endotracheal tube, 150 mcg adrenaline, defibrillator set to 60 joules

c) 4.0 endotracheal tube, 150 mcg adrenaline, defibrillator set to 60 joules

d) 4.5 endotracheal tube, 150 mcg adrenaline, defibrillator set to 30 joules

e) 4.0 endotracheal tube, 300 mcg adrenaline, defibrillator set to 60 joules

Answer: b

Explanation

The age-based formula for endotracheal tube size of (age in years/4) + 4 is well known

and well validated for children aged over one year. This formula gives a figure of 4.5. It

is recommended that at least a tube size larger and smaller should be available. The

problem with age-based formulae is that children come in such a range of sizes for any

given age. This child, at 15 kg by two years old, is on the 95th centile on the UK growth

charts, so having an even larger tube available would be wise. The intravenous bolus

dose of adrenaline is 10mcg/kg. The 2005 Paediatric Advanced Life Support guidelines

recommend an initial shock with 4 joules/kg. The previous guidelines had recommended

2 to 4 joules/kg but this has now been adjusted up to the higher figure as higher

energies effectively defibrillated children with negligible adverse effects.

Reference

Paediatric Advanced Life Support. Resuscitation guidelines. Resuscitation Council

(UK), 2005. Online at www.resus.org.uk/pages/pals.pdf (Accessed 30 October 2009)