[Hyponatremia: study of its epidemiology and mortality]

To determine the prognosis of hyponatremia in an unselected population, we collected clinical and laboratory data and determined the outcome of hospitalization for all hyponatremic patients in a general hospital during a three month period. Fourty-nine episodes of hyponatremia were analyzed. More than 90% of them were observed in hospitalized patients and were of dilutional type, and 34% were classified as severe hyponatremias (Nas less than 118 meq/l.). Diuretics plus salt restriction without water restriction were the main identifiable causes. Neurological disturbances were observed in 10.8% of patients and persisted in 4.3% of then after the treatment. Slow correction of hyponatremia was the treatment used in these patients (0.16 +/- 0.004 meq/l.h). Ten patients died, but in only one case the dead could have been caused by hyponatremia. The results showed that the morbidity and mortality of the hyponatremia is low in our institution, few patients had neurological disturbances and a favorable outcome in all of them was obtained with a slow correction of hyponatremia.