The management of children with severe diarrhoea leading to severe dehydration is a medical emergency. Look carefully for shock in all children with severe dehydration and treat immediately.
- Immediately start an intravenous infusion with Ringer’s lactate (or half normal saline or half strength Darrows/dextrose solution).
- Give 30 ml/kg over the first half hour (30 minutes). Then give 70 ml/kg over 2 ½ hours (i.e. about 30 ml/kg per hour). Most infants are therefore rehydrated with 100 ml/kg over 3 hours.
- The child must be closely observed and reassessed every half hour. If the clinical signs of dehydration have not improved after an hour, fluid should be given faster. Careful assessment after 3 hours is needed to decide whether further management should be for ‘no visible’, ‘some’ or ‘severe’ dehydration.
- If an intravenous infusion cannot be started, pass a nasogastric tube and give 20 ml/kg/hour over 6 hours (i.e. 120 ml/kg). Nasogastric rehydration is slower than intravenous rehydration as it takes time for the fluid to be absorbed. If there is repeated vomiting or abdominal distension, give the nasogastric fluid slower or try again to start an intravenous infusion.
- Only once intravenous or nasogastric rehydration has been started, should the child be moved urgently to hospital. Always start replacing fluid before moving the child. One of the commonest mistakes made is to rush the child to hospital before starting intravenous or nasogastric fluid. If no equipment is available to give fluid fast, try to get the child to drink while being urgently transported to hospital.
- Oral rehydration solution should be started when the child is able to drink.
Never rehydrate an infant or child with 5% or 10% dextrose only as they need electrolytes as well as fluid and glucose. Rehydration fluids must always contain some glucose (dextrose).
Children with severe dehydration should be rehydrated with 100 ml/kg of fluid intravenously over 3 hours.
In infants under one year it is best to give 30 ml/kg for the first hour while the remaining 70 ml/kg is given slower over a further five hours. Therefore, small infants are rehydrated slower with 100 ml/kg over 6 hours.
The amount and rate of fluid needed to correct severe dehydration has been controversial for many years. The Red Cross Children’s Hospital in Cape Town, South Africa, recommends 20 m/kg over the first 30 minutes followed by 100 ml/kg over the next 4 hours. This regimen avoids the dangers of rehydrating a child too fast.