Fatal right ventricular failure and pulmonary hypertension after protamine administration during cardiac transplantation

Protamine sulfate is the only Food and Drug administration approved medication for reversal of intraoperative heparin-induced anticoagulation during cardiac and vascular surgeries. One of the rare side effects of protamine sulfate is an idiosyncratic reaction resulting in acute pulmonary hypertension (APH) and right ventricular (RV) failure occurring after protamine administration. These reactions are rare but catastrophic with high mortality. A 36-year-old female with severe congestive heart failure was undergoing cardiac transplant surgery. After successful implantation of the donor heart, the patient was weaned off cardiopulmonary bypass. Protamine was then administered to reverse the heparin anticoagulation. She immediately developed APH and RV failure immediately after protamine infusion. The patient required immediate administration of inotropic agents, nitric oxide (NO), and subsequently required a number of mechanical support devices including an RV assist device (RVAD) and ultimately full veno-arterial extracorporeal membrane oxygenation (VA-ECMO). Despite heroic efforts, the patient developed refractory multi-organ failure in the Intensive Care Unit and died after family requested discontinuation of resuscitative efforts. This case probably represents the first reported occurrence of fatal protamine-induced APH and ventricular failure in the setting of cardiac transplantation surgery. A number of interventions including inhaled NO, systemic vasopressors, RVAD, and ultimately VA-ECMO failed to reverse the situation, and the patient died of multi-organ failure.