Abstract
Malignant hyperthermia (MH) and antithrombin III (AT III) deficiency are both rare, but once they occur, the patient's prognosis is very poor. A 67-year-old man was referred to our hospital with a diagnosis of unstable angina. A coronary angiography revealed stenosis of LMT and triple vessels. The patient was considered a candidate for CABG. He had been prescribed 50mg/day of dantrolene for frequent muscular convulsions of the lower extremities. He had had a high CK level for a few years. Therefore he was considered to be at high risk for malignant hyperthermia (MH). He underwent CABG (×4). Dantrolene was administered orally at a dose of 25mg and then 160mg intravenously before anesthesia and modified NLA was performed in order to avoid probable MH. During the operation, AT III deficiency was suspected because the reaction of ACT after heparinization was poor. AT III preparation (1, 500 units) was used and CABG under cardiopulmonary bypass was completed without any events. It was proved after the surgery that the AT III volume had been almost normal but its activity had decreased. His postoperative course was good. For possibly fatal MH and AT III deficiency, it is necessary and important to predict, prevent and diagnose as early as possible.