Abstract 13: Management of hyponatremia: Clinical audit

Background: The concentration of sodium in plasma is maintained within a relatively narrow range by homeostatic mechanisms involving thirst, arginine vasopressin (AVP) and renal control of water excretion. Hyponatremia is defined as serum sodium level <135 meq/L. It is the most common electrolyte abnormality seen in hospital admissions worldwide. A wide variety of factors influence the outcome of the hyponatremic patient. We aimed to analyse etiology, severity of hyponatremia, treatment and rate of correction of sodium in hospitalized patients. Methods: We analysed 61 hospitalized patients with hyponatremia referred to department of endocrinology from other specialities. Serum sodium was recorded at the time of referral. Depending upon their symptoms, clinical examination and concurrent illness; treatment options were employed. These patients were followed up with serial sodium levels over 24, 48, 72 and 120 hours and their rate of correction was recorded. Results: Out of total 61 patients, 41 were male and 20 were female. Among them 54% (n = 33) of the patients were elderly (>60 years age). Mean sodium level at the time of referral was 127.82 mEq/L. 65% (n = 40) of the patients had underlying neurological cause of hyponatremia; possibly SIADH, 22.9% (n = 14) patients had drug induced hyponatremia, 6 patients had hypovolemic hypernatremia, 1 patient had hyponatremia due to severe hypothyroidism. Of all, 83.6% (n = 51) of patients were treated with tolvaptan along with oral sodium supplement. 10 patients did not require tolvaptan owing to their mild degree of hyponatremia. 21.3% (n = 13) of patients required use of 3% saline; out of which 10 patients had underlying neurological cause, 1 patient had drug induced hyponatremia and 2 patients had severe hypovolemic hyponatremia. In the patients who were given tolvaptan, mean increase in serum sodium after 24 hours was 4.7 mEq/L and after 48 hours was 5.4 eEq/L. In them 8 patients had increase in serum sodium by 38 mEq/L at 24 hours. Tolvaptan was discontinued in 3 patients due to elevated liver enzymes. Mean sodium at the time of discharge was 134.5 eEq/L for the patients treated with tolvaptan. Mean duration of hospital stay was 17.12 days. There was no mortality recorded among 61 patients. Conclusion: Timely recognition and initiation of treatment is crucial in patients with hyponatremia. Early specialist input, clarity of diagnosis, and robust communication across the healthcare community could improve outcomes and patient experience.