Severe hypokalemia in thyrotoxic periodic paralysis.

Thyrotoxic hypokalemic periodic paralysis is an uncommon but sometimes fatal disease in which early recognition and therapy may prevent untoward complications. The case of a 26-year-old Chinese man who presented to the emergency department with rapidly progressive profound weakness and severe hypokalemia (serum potassium, 1.2 mEq/L) is presented. The patient required endotracheal intubation, ventilatory assistance, and intravenous potassium administration. Emergency medical evaluation and management of this entity are discussed.