A case of the effective inhalation of nitric oxide therapy for caused severe pulmonary hypertension with protamine neutralization of systemic heparinization during totally endoscopic minimally invasive cardiac surgery

Severe pulmonary vasoconstriction induced by protamine is a rare complication. We report a case of a 77-year-old male patient who had a history of mitral valve plasty (MVP). He underwent redo MVP via right thoracotomy under the totally endoscopic procedure (MICS redo-MVP). Immediately after weaning cardiopulmonary bypass (CPB), protamine was administrated. 10 minutes later peak systolic pulmonary arterial pressure (sys PAP) rose to 62 mm Hg, and 30 minutes later to 80 mmHg. Due to the negative impact of protamine administration, nitric oxide inhalation (iNO) therapy was started with a concentration of 20 ppm. 10 minutes after iNO therapy started, sys PAP decreased to 63 mmHg. After entering the intensive care unit (ICU), sys PAP decreased to 35 mmHg. Here, we present an effective iNO therapy case for pulmonary hypertension due to protamine and the patient had a good postoperative recovery.This study was approved by the Institutional Review Board at Kitaharima medical center (IRB-0602) with the waiver of informed consent.