Fatal bilateral phrenic nerve injury following hypothermic open heart surgery

A 30-year-old woman underwent mitral valvotomy for severe mitral stenosis. Extracorporeal circulation by means of cardiopulmonary bypass and systemic hypothermia, in addition to local topical hypothermia using iced saline solution and slushed ice, was used. Fatal bilateral phrenic nerve paralysis with inability to wean her from the ventilator occurred. This report is presented to illustrate the pathophysiology, pathology, and means of possible prevention of such a potentially highly fatal injury following hypothermic open heart surgery.