Endocrine Abstracts (2016) 41 EP758 | DOI: 10.1530/endoabs.41.EP758

Treatment of mild-moderate hyponatraemic encephalopathy with intravenous bolus therapy of 3% hypertonic saline solution: a case series

Guillermo Ropero Luis1, José Abuín Fernández2, Francisco Sánchez Torralvo2, Beatriz Rivas Sánchez1, Estíbaliz Romero Masa1, Viyey Kishore Doulatram Gamgaram2, Sonia Santamaría Fernández1 & Ricardo Gómez Huelgas1

1Department of Internal Medicine, Hospital Regional Universitario de Málaga, Málaga, Spain; 2Department of Endocrinology and Nutrition, Hospital Regional Universitario de Málaga, Málaga, Spain.

Introduction: Hyponatraemia is the most common electrolytic disorder in clinical practice. We designed a protocol, based on the latest consensus statements and adapted to our Hospital, for the use of 3% hypertonic saline solution (HSS) in patients with hyponatraemia.

Material and methods: Unicentric observational study of a case series. We collected data from 14 adult patients with severe hyponatraemia (serum sodium [SNa] <125 mmol/l) and mild-moderate hyponatraemic encephalopathy (no signs of brain herniation) treated with an intravenous bolus of 250 ml of HSS over 30 minutes and reevaluated 6 hours later. Our goal was to raise 4–6 mmol/l as soon as possible, and 6-8 mmol/l in 24 hours with a limit of 12 mmol/l. The bolus was repeated if SNa raised <3 mmol/l.

Results: Median age (IQR) was 69.9 (64.5–78.1) years, and 62% were female. Baseline median SNa was 120 (114.3–122.8) mmol/l. Median SNa 6 hours after the bolus was 124.4 (120.7–128.3) mmol/l, a median raise of 5 (4.4–6.2) mmol/l (P<0.001). One patient required an additional bolus. Median SNa raise 24 hours after the bolus was 6 (3.9–8.2) mmol/l (P<0.01) in 9 patients; there was no significant change between 6 and 24 hours. Median rise per 100 ml of HSS was 2 (1.7–2.5) mmol/l after 6 hours and 2.4 (1.6–3.3) mmol/l after 24 hours. No patients required treatment for overcorrection nor had adverse outcomes. No significant changes were observed in serum potassium and creatinine.

Conclusions: Our data suggests that this protocol is safe and effective to reach the goals in the treatment of severe hyponatraemia with mild-moderate encephalopathy in the first 6 hours, without noticeable side effects or overcorrection. Patients at low risk of osmotic demyelination may receive another bolus to reach a higher SNa in 24 hours. Larger studies are required to confirm these results.