Two Cardiac Arrests that Occurred after the Administration of Sugammadex: A Case of Kounis Syndrome.

Kounis syndrome is a form of acute coronary syndrome caused by allergic reactions. No cases of cardiac arrest caused by Kounis syndrome that arose after the administration of sugammadex have been reported. A 71-year-old female suffered two cardiac arrests. The first occurred after sugammadex was administered at the end of an operation for a right radial distal fracture. The patient was resuscitated and transferred to our intensive care unit. She was subsequently discharged home. Five months later, she suffered a second cardiac arrest after sugammadex was administered at the end of an operation for a right femoral neck fracture at our hospital. Urgent coronary angiography revealed multiple coronary spasms. Kounis syndrome was diagnosed based on the patient's elevated serum trypsin levels and a positive result in a skin allergy test of sugammadex. In cases of cardiac arrest with unclear etiologies, Kounis syndrome should be considered.