Background Hyponatremia, the most common electrolyte disturbance in clinical practice affecting up to 15%–28% of admitted patients, is defined as a serum sodium concentration ([Na+]) <135 mmol/L. Hyponatremia at admission is known to increase the duration and cost of stay of hospitalized patients. The prevalence of hyponatremia in palliative care is about 28% of at the time of referral. Hyponatremia can be asymptomatic or can cause symptoms like nausea and lethargy to convulsions and coma. It is important to evaluate the cause of hyponatremia to have a targeted management strategy.

Methods A retrospective case note analysis was carried out among patients admitted under a palliative care unit of a tertiary referral hospital in South India, over a period of 6 months. The sodium level on admission and during the inpatient stay, along with symptoms, drug history and cause of hyponatremia was evaluated.

Results Out of 11 patients who presented with hyponatremia, median age was 59;7 patients were male. All the patients had a cancer diagnosis, with 28% had cancer of GI tract,91% had stage IV disease. The median sodium level on admission was 125;82% had hypotonic hyponatraemia. 37% were asymptomatic on presentation,while 18% had generalised weakness.Median number of drugs for each patient was 4 and a number of drugs were implicated to cause hyponatremia.55% of patients were found to have a diagnosis of SIADH,the other causes were extrarenal solute loss(18%), Pseuohyponatremia (18%) and cirrhosis (9%).Only 45% were treated with Tolvaptan,while the rest had sodium replacement, fluid restriction and other supportive care.27% died during the admission and 36% died within the next 6 months of discharge.

Conclusions SIADH is not always the cause of hyponatremia in palliative care patients, hence there is a need for accurate diagnosis of patients to enable a targeted management strategy.