[Treatment of severe hyponatremia by restricted water intake]

The outcomes of 23 patients admitted to a medical intensive care unit for severe hyponatraemia (less than 120 mEq/l) associated with neurological disorders were reviewed. All patients had restricted water intake combined with a sodium intake adjusted to the natriuresis, and some received a loop diuretic. The mean correction rate during the first 48 hours was slow (greater than 12 mmol/l.24 h) in 16 cases and fast (less than or equal to 12 mmol/l.24 h) in 7 cases. Following biochemical cure, 2 patients in the fast correction group had an unfavourable outcome: one died for an unknown reason, the other developed pontine myelinosis. A review of the literature did not provide evidence that a certain rate of correction was better than the other, but it showed that an excessive rise in natraemia or an overcorrection of hyponatraemia was dangerous. Slow correction of hyponatraemia, usually obtained with water intake restriction, may be recommended.