Suspected venous oxygen embolism following hydrogen peroxide wound irrigation causing intraoperative asystole

A man in his 20s underwent wound debridement and external fixation for a femoral fracture sustained in a blast injury. Anaesthesia was induced with propofol and nalbuphine and the airway was secured with an i-gel laryngeal mask. About 45 min after induction, irrigation of the semiclosed wound with hydrogen peroxide was followed by a sudden fall in end-tidal carbon dioxide and tachycardia, which progressed rapidly to asystole. Cardiopulmonary resuscitation was started immediately, and tracheal intubation was performed during the first cycle of compressions. Return of spontaneous circulation occurred 6 min later. The patient recovered fully with no neurological or cardiovascular sequelae. The close temporal link between hydrogen peroxide irrigation and circulatory collapse was suggestive of intraoperative oxygen embolism, likely facilitated by oxygen liberation in a confined cavity. This case highlights the need to limit or avoid the use of hydrogen peroxide as irrigant whenever possible, and exercise caution and preparedness whenever its use becomes unavoidable.