Heparin-protamine management: a comparison study of three different heparin-protamine management protocols

Abstract

In a prospective randomized open study, 180 patients underwent open-heart surgery using cardiopulmonary bypass (CPB) and were divided into three different heparin-protamine management protocols. Each group consisted of 60 patients. Patients were treated according to: (A) their dose-response curve using the Hemochron 800 system (International Technidyne Corporation): (B) their dose-response curve, but the heparin-protamine management was based on titrations using the Hepcon system 4 (Hemotec Inc.); or (C) the regular protocol in our hospital. The three groups were compared according to age, gender, weight, perfusion time and operation type. Fibrinogen levels and activated partial thrombin time (APTT) were measured before and after CPB1: during CPB, activated clotting time (ACT) was monitored.2-4At the onset of CPB an ACT value of at least 480 seconds was standard.4 Blood for ACT evaluation was drawn every 30 minutes during CPB. A significant difference in the heparin dose given to the different groups was noted, but there also was a significant difference in bodyweight. As calculated per kilogram bodyweight, group B's heparin dose was significantly lower than group A's and also significantly lower than group C's. Group C was given a significantly higher dose of protamine/kg than group A and group B, and Group B's dose was significantly higher than group A's. Hence, protamine/heparin ratios of 0.61 for group A, 0.74 for group B and 0.82 for group C resulted. There was no significant difference in blood loss for the three groups and there was also no significant difference in the use of bank blood for these three groups. APTT values, measured after protamine administration, were significantly higher in group A than in group C. This study suggests that a higher dose of protamine does not result in a decrease of blood loss postoperatively. Reduction in the amount of heparin and in the protamine/heparin ratio is possible by guiding the Hepcon or Hemochron measurements. This reduction, however, will not directly decrease postoperative blood loss. Accurate doses of heparin and protamine can be achieved with an individual patient-related protocol. Thus, an unnecessary excess of heparin and/or protamine can be eliminated.