Presumed Malignant Hyperthermia Treated During Cardiopulmonary Bypass in a Pediatric Patient Undergoing Aortic Valve Replacement: A Case Report.

There are no case reports of malignant hyperthermia in pediatric patients treated on cardiopulmonary bypass (CPB). We report the case of a 10-year-old boy undergoing aortic valve replacement. The patient developed progressive tachycardia and hypercarbia. In addition, EtCO2 and PaCO2 were equal and myoglobinuria was suspected given darkened urine. Numerous dantrolene boluses were given on CPB, and a dantrolene infusion was started. The patient's base deficit and creatine phosphokinase normalized by postoperative day 2. This case demonstrates the importance of expeditious diagnosis of malignant hyperthermia, and the need for additional dantrolene when treating patients whose blood volume is diluted on CPB.