Hyponatraemia associated with pneumonia or bacterial meningitis.

Serum sodium concentrations were measured in 93 children with pneumonia or bacterial meningitis on their admission to hospital. Hyponatraemia (sodium value 134 mmol/l or less) was present in 33 (45%) of the 73 children with pneumonia, and in 10 (50%) of the 20 children with bacterial meningitis. Increased secretion of antidiuretic hormone is common in children with pneumonia, as well as in children with meningitis. The maintenance fluid requirement in these children is usually about 50 ml/kg/per day, and children with hyponatraemia caused by water overload need even lower fluid intakes. In developing countries, most children with pneumonia and meningitis should be managed without intravenous fluid treatment.