INTRA-AORTIC ADMINISTRATION OF PROTAMINE - METHOD FOR HEPARIN NEUTRALIZATION AFTER CARDIOPULMONARY BYPASS

Abstract

In neutralizing heparin with i.v. protamine sulfate, hypotension may be prevented by administering the drug intraarterially. Forty patients underwent cardiac surgery with extracorporeal circulation; each received a rapid injection of nondiluted protamine sulfate in the aortic root to reverse the effects of heparin. To maintain the blood volume at a constant level, volume expanders and inotropic drugs were avoided. The intraaortic injections ranged in duration from 0.2-2.8 min, with a mean of 1.1 min. The mean systolic pressure dropped from 92 mm Hg (SD .+-. 21) before protamine injection to 85 mm Hg (SD .+-. 23) after injection (P < 0.0001). In 7 patients (18%) no hypotension was evident; in the remaining patients the systolic pressure returned to preinjection values within a mean of 2.2 min. Coagulation was observed within 3-4 min (mean = 2.2 min) after the initiation of injection. Intraaortic administration of protamine evidently is a rapid and safe technique for heparin reversal after cardiopulmonary bypass.