SAFETY ISSUES IN HEPARIN AND PROTAMINE ADMINISTRATION FOR EXTRACORPOREAL-CIRCULATION

This article reviews past approaches to heparin and protamine dosing a nd summarizes current practice. The author elucidates his experience w ith the Celite activated coagulation time (ACT), with attention to his adoption of a value of 400 seconds for this time; the adoption of an ACT of 480 seconds by Bull et al (J Thorac Cardiovasc Surg 69:674-684, 1975) and Young et at (Ann Thorac Surg 26:231-240, 1978); the propose d use of heparin response curves by Bull et al; the author's experienc e with a unitized dosing system to individualize dosing of heparin; an d the use for this purpose by Despotis et al (J Thorac Cardiovasc Surg 110:46-54, 1995) of a system based on protamine titration. In more th an 270 adult cardiac surgery patients, the unitized dosing system iden tified patients with high sensitivity or resistance to heparin and fac ilitated exact individualized doses to be given to produce the desired effect. Thus, less heparin was used in short bypass runs. Patients re ceived less protamine than they would have with any other formula, and there was less blood loss and fewer transfusions required. Currently, no claims for efficacy or safety can be made for maintaining heparin concentrations greater than 3 U/mL. Pending further clarification, hep arin dosage cannot be safely reduced when using heparin-bonded circuit s. Aprotinin is not a procoagulant during cardiopulmonary bypass. Emer ging studies suggest that graft patency is not affected by aprotinin u se. The Celite ACT should not be used to monitor heparin effect and sa fety when using aprotinin; the kaolin ACT should be used instead. Copy right (C) 1998 by W.B. Saunders Company.