Hyponatraemia in severe falciparum malaria: a clinical study of nineteen comatose African children.

In a prospective study, hyponatraemia was observed in 52.6% of 19 children with cerebral malaria on admission, the plasma sodium ranging from 117 to 129 mumol/l. In addition, a further 10% developed hyponatraemia between 48 and 96 hrs after admission; in half of these, there was continuing urinary sodium loss. The clinical presentation of hypo- and normonatraemic children was similar except for vomiting and hypoglycaemia which were commoner in the normonatraemic and irritability and signs of lower respiratory tract infection which were commoner in the hyponatraemic groups. In hyponatraemic and normonatraemic children, there was a negative correlation between hyponatraemia and parasite density (r = -0.503, P < 0.05) and (r = -0.14, P < 0.05 respectively) and between parasite density and urinary sodium concentration during the first 24 hours of admission (r = -0.034; P < 0.05 and r = -0.045, P > 0.05 respectively). Irrespective of group, a relative increase in plasma sodium in the first 24 hours of admission (positive delta Na 24 h) was associated with a reduction in seizure frequency during this period as compared to the reported 24 hour of pre-admission seizure frequency, and, vice-versa. It is concluded that hyponatraemia is not uncommon in childhood cerebral malaria; urinary sodium loss may be contributory to the hyponatraemia seen in this condition.