A 70-year-old man with chronic kidney disease stage 3b owing to previous episodes of acute kidney injury (AKI) and ischemic colitis treated with end-ileostomy was admitted with atrial fibrillation with a rapid ventricular rate and hypotension. He was started on a heparin infusion and underwent cardioversion without resolution of arrhythmia. His hospital course was complicated by prerenal nonoliguric AKI owing to high ostomy output, decreased oral intake, and low blood pressure. His creatinine was 4.7mg/dL, up from a baseline of 2.4mg/dL, and serum potassium and bicarbonate levels were 5.6 mEq/L and 10 mEq/L, respectively (Table 1).