Aetiological evaluation of hyponatremia in hospitalised patients and its prognostic implication in disease outcome

Abstract

Background: Hyponatremia is very common in clinical practice. Proper evaluation of hyponatremia is essential as causes are many and management of it depends on the aetiology and its long-term outcome. Aetiological evaluation of hyponatremia in hospitalised patients and its prognostic implication in disease outcome was undertaken as such studies were rare in this zone.Methods: One hundred patients whose serum sodium level was <135 mEq/L were studied. The serum sodium and osmolality and urinary sodium and osmolality were estimated in all. The degree of hyponatremia, outcome after treatment and duration of hospital stay were analysed.Results: The mean age was 60.5 years. There were 73% males and 27% females. The incidence of hyponatremia was 10.7%. The mean serum sodium was 129.96 mEq/L and urinary sodium was 40.3 mEq/lL while the mean serum osmolality was 272.8 mOsm/kg and urinary osmolality was 357.7 mOsm/kg. Euvolemia, hypervolemia and hypovolemia were observed in 51%, 28% and 21% respectively. The common clinical features were drowsiness (22%), disorientation (20%), fever (28%), nausea (24%), anorexia (15%), vomiting (14%), hiccup (10%). The common causes were SIADH (34%), renal causes (15%), sepsis (13%), endocrinopathy (11%) and diuretics (11%). The common comorbidities were hypertension (66%) and diabetes mellitus (41%). The mortality was 7%. No side effect was observed during management of hyponatremia.Conclusions: Proper management of hyponatremia irrespective of aetiology had a better prognosis. Factors which are modifiable should be searched and rectified.