The silent potassium avalanche: unchecking preoperative hypokalemia leading to perioperative cardiac arrest in an insulin-treated diabetic patient undergoing a Whipple procedure: a case report

Perioperative cardiac arrest after pancreaticoduodenectomy is uncommon but often catastrophic. Hypokalemia is a modifiable risk factor for malignant arrhythmia, particularly in insulin-treated diabetic patients exposed to bowel preparation and fasting. We report one of the few well-documented cases demonstrating a rapid decrease in serum potassium from a normal value to life-threatening hypokalemia within 72 h. A 67-year-old woman with type 1 diabetes and hypertension underwent elective laparoscopic pancreaticoduodenectomy. The serum potassium concentration measured three days preoperatively was 5.28 mmol/L, whereas a point-of-care test immediately before the incision was made revealed a value of 2.71 mmol/L. Intravenous potassium chloride was administered intraoperatively with partial biochemical correction (3.28 mmol/L later that day). The operation was completed without major bleeding; the patient was extubated and transferred to the ward. Approximately 30 min after ward arrival, she developed hypertension and tachyarrhythmia that progressed to pulseless electrical activity and cardiac arrest. The return of spontaneous circulation was achieved after resuscitation, but the patient subsequently developed hypoxic-ischemic encephalopathy, multiorgan dysfunction and sepsis and died 14 days after intensive care unit admission. This case highlights the potential for rapid and catastrophic electrolyte shifts in insulin-treated diabetic patients undergoing bowel preparation and major abdominal surgery. We suggest routine electrolyte reassessment within 24 h preoperatively for high-risk patients, early point-of-care potassium testing when indicated, prompt correction to normal potassium levels before major surgery, and enhanced postoperative monitoring for patients at elevated risk.