1University Hospital Geelong, Barwon Health, Victoria

Background: Severe hyponatraemia is a life-threatening condition which must be carefully corrected due to the risk of osmotic demyelination syndrome (ODS). Beer potomania refers to a form of hypotonic hyponatraemia which occurs in the context of excessive beer intake and a low solute diet, with impaired free water excretion.

Case Report: A 41-year-old female with a history of alcoholism and depression, on desvenlafaxine, presented to her General Practitioner (GP) with flank pain two days after being caught on a fence for four hours. Bloods tests revealed acute kidney injury and rhabdomyolysis. Her creatinine kinase (CK) level was 11,616 U/L, serum sodium 121 mmol/L, and creatinine 686 µmol/L. Following the event, she had poor oral intake, however continued to drink four litres of beer daily. She was subsequently uncontactable by her GP, though five days later presented to hospital with slurred speech and confusion. Despite an improving CK of 467 U/L, her serum sodium had dropped to 102 mmol/L and creatinine had risen to 1080 µmol/L. She was oligo-anuric, however not clinically fluid overloaded. Dialysis was deferred due to the risk of ODS with rapid sodium correction. Desvenlafaxine was with-held and normal saline commenced at 100 ml/hour achieving rapid diuresis. Her sodium was corrected by 3-7 mmol/day in intensive care, using normal and hypertonic saline for the first three days. She has since completely recovered with no neurological sequelae.

Conclusion: We report a case of multifactorial hyponatraemia in the context of beer potomania, acute kidney injury secondary to rhabdomyolysis, and desvenlafaxine therapy. This raised challenges in the interpretation and management of hyponatraemia, and highlighted the potential dangers of dialysis in this setting.