Endocrine Abstracts

Background: Amongst hospitalised patients, hyponatraemia is the commonest electrolyte abnormality with reported prevalence of about 25%. Its association with mortality, morbidity and increased length of stay is well recognised, including adverse fracture risk and falls with mild hyponatraemia in elderly. We audited the management of hyponatraemia in inpatients in a University hospital setting.

Methods: Over a 3-month period, amongst all in-patients, we identified those who had hyponatraemia (serum Na≤130 mmol/l) from the in-house biochemistry database. Data on their demographics, management of hyponatraemia, length of stay and mortality was obtained and analysed.

Result: Of the 109 patients identified with hyponatraemia – their gender: 46% male; age: 75±14 years (mean±S.D.), with 60% being over 75 years age. The proportion who had serum Na <120, 121–125 and 126-130 mmol/l were 22, 24 and 54% respectively. Majority were managed in medical wards (91%) – acute medicine 19%, care of the elderly 27%, endocrine 19%, gastroenterology 10%, general medicine 8% and other medical specialities including respiratory medicine 8%. Only 21% had Endocrine specialist input. SIADH, fluid overload and drugs were attributed as cause for the hyponatraemia in 16%, 14% and 10% respectively and remaining 60% was due to other causes including vomiting and/or diarrhoea or where no clear cause was identified. The in-hospital mortality was 9.2% in the cohort, amongst whom 40% had serum Na <125 mmol/l. Of the 88.8% discharged, 36% and 35% had serum Na≤130 mmol/l and ≤125 mmol/l at discharge. The average length of stay in those discharged was 12.4 days.

Conclusions: This audit demonstrates the potential deficiencies in the optimum management of hyponatraemia in inpatients setting. Large proportion had Na <130 mmol/l on discharge which is potentially associated with adverse outcomes especially in the high risk elderly population.