MRCP2-0614

MRCP2-0614

A 28-year-old mechanic is brought to the emergency department by his girlfriend. He is confused and lethargic. According to his girlfriend, they had been drinking alcohol the previous night, and he has been increasingly confused throughout the day despite no further alcohol intake. She also reports that he has been feeling low and has expressed suicidal thoughts recently.

Upon assessment, his Glasgow coma scale is 14/15, and his pupils are equal and reactive to light. His blood pressure is 124/81 mmHg, and his heart rate is 97/minute. He has a respiratory rate of 32/minute and oxygen saturations of 94% on room air. There is bilateral flank tenderness, but the rest of the clinical exam is unremarkable.

His urine toxicology screen is negative, but the urine dipstick is positive for blood. The arterial blood gas shows a pH of 7.10, PO2 of 12.3Kpa, PCO2 of 2.6Kpa, bicarbonate of 8.0mEq/L, and lactate of 2.3mmol/L. His biochemistry results show a sodium level of 145 mmol/L, potassium level of 3.8 mmol/L, chloride level of 105 mmol/L, urea level of 11 mmol/L, creatinine level of 113µmol/L, glucose level of 5.7mmol/L, and serum osmolality of 358 mOsm/Kg. His ethanol level is <10 mmol/L, and his paracetamol level is 0 mg/dl. What is the most likely cause of this 28-year-old mechanic’s presentation?