ABSTRACT
To determine the incidence and etiology of hyponatremia in adult hospitalized patients in medical wards of a general hospital. The four medical wards comprising a total of 140 beds in a 500 bedded general hospital in Kuwait. Retrospective study of hyponatremia analyzed and reported by the biochemistry laboratory from June to December 2004. All adult patients admitted to medical wards during the six month period from June to December 2004 having serum sodium < 130 mmol/lOut of a total of 1825 patients analyzed over a six months period [from June - December 2004], 66 patients [3.6%] had hyponatremia. Of these 37 [56%] were male and 29 [44%] female. Their mean age was 57.05 years. The commonest age group was 45 - 64 years and the least affected group was 12-25 years. Their mean serum sodium level was 122 mmol/l. Among the major causes of hyponatremia was the Syndrome of inappropriate secretion of antidiuretic hormone [SIADH] with pneumonia. Next to SIADH, renal failure and cardiac failure were the two common causes. Overall incidence of hyponatremia was 3.6% in all medical patients reviewed. The commonest cause of hyponatremia was found to be SIADH due to pneumonia. Renal failure and cardiac failure were the other two common causes. Identification of the cause of hyponatremia is important in order to impart specific treatment. Correction of hyponatremia improves prognosis of the underlying disease and prevents further complications due to hyponatremia itself. It is important to be cautious not to correct hyponatremia too rapidly and also not to exceed a level of 120 to 125 mmol/l [acutely], in order to p revent the complication of osmotic demyelinating syndrome