Cardiac Arrest with Extreme Hyperkalemia

A 34-year-old man with type 1 diabetes, which is being treated with a subcutaneous insulin self-injection, presented to the emergency department in a state of coma. The patient had skipped taking the insulin injection for four days and then complained of fatigue and epigastralgia. On the day of hospital arrival, his mother found him unconscious in his room at home and an ambulance brought him to our hospital. At the time of arriving at the emergency department, he had cardiac arrest and his electrocardiogram (Figure 1a) revealed pulseless electrical activity. Cardiopulmonary resuscitation was immediately performed. His serum glucose concentration was 1.178 mg/dL, arterial blood pH was 6.69, and serum potassium concentration was 10.6 mEq/L.