Clinical profile of patients with hyponatremia in a tertiary care hospital in the sub-Himalayan region

Abstract

Introduction: Hyponatremia, defined as a serum sodium concentration ([Na+]) <135 mEq/L. It is not a disease but rather a pathophysiologic process indicating disturbed water homeostasis. Hyponatremia should be further classified to provide directions for diagnosis and treatment. It is a heterogeneous disorder. The classifications of hyponatremia are commonly based on tonicity and volume status. The initial differentiation in hypotonic and non-hypotonic hyponatremia is important because management is different. Several studies have been conducted previously to measure the incidence of hyponatremia in medically ill patients. Several studies have demonstrated an increased prevalence of hyponatremia in the presence of co-morbid conditions. We conducted this study to bring out various causes of hyponatremia; their relation with sex, age and outcome and hyponatremia's classification and incidence in our hospitalised population. Materials and Methods: This study was conducted to find out etiology, classification, prevalence and outcome and its relation with age and sex in patients of hyponatremia admitted in our institution. A total number of 106 patients were studied. Results: Hospital-based incidence of hyponatremia was found to be 1.17%. Mean age of patients in study was 62.25 ± 17.7 years. Male to female ratio was 1.25:1. Altered sensorium was the most common neurological symptom. Ninety-five (90%) patients were hypo-osmolar. Out of ninety four patients, 38 (40%) were euvolemic. Chronic obstructive pulmonary disorder (COPD) with cor pulmonale with right-sided heart failure (n = 9, 31%) was the most common cause in hyper-volemic hyponatremia. Acute gastroenteritis (n = 13, 48%) was the most common cause in hypo-volemic hyponatremia. Syndrome of inappropriate anti-diuretic hormone secretion (SIADH) was the most common cause (n = 20, 53%) of euvolemic hyponatremia. Out of 106 patients, 11 (10.38%) patients expired. Conclusion: Hyponatremia acts as a poor prognostic marker of the primary disease. It is important to recognise it early because of the potential morbidity and mortality, economic impact on the patients and health care associated with it. Early management of hyponatremia, which includes determination of the rate of correction, the appropriate interventions and the presence of other underlying disorders, may help in improving the outcome and shortening the hospital stay of the patients.

Keywords

• aetiology
• hyponatremia
• incidence
• syndrome of inappropriate anti-diuretic hormone secretio