Paediatric Fluid Prescriptions

Fluid prescribing in children replaces a deficit, supplies maintenance needs and replaces ongoing losses, with resuscitation boluses reserved for circulatory failure. Isotonic fluids are the safe default because hypotonic fluids carry a risk of hyponatraemia and cerebral oedema.

Assessing dehydration. No dehydration: alert, drinks normally, normal skin pinch. Some dehydration: restless or irritable, thirsty, sunken eyes, skin pinch returns slowly (under 2 seconds). Severe dehydration: lethargic or unconscious, unable to drink, very slow skin pinch (over 2 seconds), with or without shock. Shock: cold extremities, capillary refill over 3 seconds, weak fast pulse, low blood pressure as a late sign.

Fluid deficit. Each 1% loss of body weight corresponds to about 10 mL/kg of fluid. Use measured weight loss when a recent weight is available.

• No dehydration (diarrhoea): low osmolarity oral rehydration solution 10 mL/kg after each loose stool (50 to 100 mL under 2 years; 100 to 200 mL for 2 to 10 years), continue feeding, and give zinc 10 mg once daily under 6 months and 20 mg once daily for 6 months and over, for 10 to 14 days.
• Some dehydration: oral rehydration solution 75 mL/kg over 4 hours (50 mL/kg for mild to moderate in some practice), reassess, and then give maintenance. Use a nasogastric tube if the child cannot drink but is not in shock.
• Severe dehydration without shock: Ringer’s lactate or 0.9% sodium chloride 100 mL/kg total. Infants under 12 months: 30 mL/kg over 1 hour, then 70 mL/kg over 5 hours. Older children: 30 mL/kg over 30 minutes, then 70 mL/kg over 2.5 hours. Reassess hourly and change to oral rehydration solution 5 mL/kg/h when the child can drink.
• Shock: 10 to 20 mL/kg of isotonic crystalloid (0.9% sodium chloride or balanced solution) rapidly, reassessing after each bolus. Stop boluses once perfusion normalises and escalate after 40 to 60 mL/kg.
• Shock in severe acute malnutrition: 15 mL/kg of Ringer’s lactate with 5% glucose (or half-strength saline-glucose) over 1 hour, then reassess. Do not repeat large boluses; switch to blood if there is no improvement and anaemia is likely.
• Hypoglycaemia during rehydration: 2 mL/kg of 10% glucose.
• Hypernatraemic dehydration (sodium over 150 mmol/L): replace the deficit over 48 hours and keep the sodium fall under 0.5 mmol/L/h and 12 mmol/L in 24 hours.

Fluid choice. Isotonic crystalloid with 5% glucose for maintenance in a child with deficit, adding potassium chloride 20 mmol/L once urine is passing and potassium is not high.

Cardiac, renal and head injury. Restrict to two thirds of maintenance and avoid boluses unless the child is in shock. Diabetic ketoacidosis: avoid routine boluses, give 10 mL/kg only for shock, and replace the deficit over 48 hours.

Febrile illness without hypotension. In settings with limited intensive care, rapid large boluses have been linked with higher mortality in severely ill febrile children, so give 10 mL/kg slowly or maintenance only and reassess.

Special groups. Neonates and children with cardiac or renal disease need specialist direction. In East Africa, cholera outbreaks need high-volume early rehydration and a cholera cot to measure output.

Monitoring. Reassess heart rate, capillary refill, respiratory rate and consciousness after every bolus. Weigh before and after, record urine output (target over 1 mL/kg/h, over 2 mL/kg/h in infants), and check sodium, potassium and glucose within 6 hours in severe cases.

Referral and escalation. Escalate for persistent shock after 40 mL/kg, hepatomegaly or crackles after a bolus (stop fluids), seizures, sodium under 125 or over 155 mmol/L, or any child with malnutrition and shock.

Stopping. Move to oral rehydration or enteral feeds once the child drinks and perfusion is normal.