Paediatric fluid and electrolyte management

Meet the patient

A 9-month-old, 8 kg infant is brought to the resuscitation bay after three days of vomiting and profuse watery diarrhoea. She is lethargic but rousable, capillary refill 4 seconds, mucous membranes dry, and the fontanelle sunken; the bedside glucose is 2.1 mmol per litre. The registrar reaches for a 20 mL per kilogram bolus and a bag of 0.45 per cent saline in dextrose. Treat the hypoglycaemia first with 2 mL per kilogram of 10 per cent glucose (RCH). If she is in shock, the bolus is an isotonic crystalloid — 10 mL per kilogram (NICE NG29) to 20 mL per kilogram (RCH) — not hypotonic 0.45 per cent saline.[16][23][20]

Three questions decide her next hour and every paediatric fluid prescription: is the child in shock? (the bolus is only for shock), what is the maintenance tonicity? (isotonic, never 0.45 per cent), and what is the sodium and its correction ceiling? (the rate that protects the brain). Hold those three and the four prescriptions fall into place.[1]

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