Endocrine Abstracts

Background: Hyponatremia is the most encountered electrolyte abnormality and is associated with high morbidity and mortality rates. An accurate diagnosis requires careful clinical and biochemical assessment. Due to patient safety incidents a retrospective 5-year audit was undertaken to study current management of acute profound hyponatremia (Na <125 mmol/l) at our institution compared to European consensus guidelines.

Methods: All patients with acute Na<125 were identified from biochemistry records from 2017-22. Case note review, investigations, management and outcome was reviewed.

Results: A total of 121 patients were identified (56% female). Mean age was 65 years (range 23-97). Mean Na was 111.9, with 3 cases of Na<100 (analytical limit of assay). 47% were asymptomatic, 37% moderately symptomatic and 15% severely symptomatic. The most common symptoms were confusion (31%), seizures (16%) and vomiting (12%). Volume status wasn’t determined in 12%; 35% were deemed hypovolaemic, 33% euvoleamic and 20% hypervoleamic. As far as investigations are concerned 43.8% had none, 23.9% had incomplete and 32.2% had complete investigations. No cases of hypoadrenalism or hypothyroidism were identified. 1.8% hypertonic saline was used in 23 patients on the wards, and one received 3% hypertonic saline in ITU (8 severe symptomatic, 14 moderate symptomatic, 2 asymptomatic). 11 severely symptomatic patients were not given hypertonic saline despite being indicated. The data also reveals 66% of the patient who had received hypertonic saline had no indication. 9% of patients overcorrected at either 24 or 48 hours. Of these, 63% had hypertonic saline and 37% had 0.9% saline. However, none developed symptoms of osmotic demyelination. Mortality was 26% at 30 days and 52% at 1 year.

Conclusion: Investigation and appropriate management of hyponatremia remains a challenge despite international consensus guidelines. Mortality remains elevated but in line with previous studies. Further work is needed to reduce the risk of harm to this patient group.