Effects of hemofiltration on serum aprotinin levels in patients undergoingcardiopulmonary bypass

Objective: To determine the effects of hemofiltration on serum aprotinin le vels during cardiopulmonary bypass (CPB) surgery. Design: Prospective, randomized study. Setting: University of Washington Medical Center, single institution. Participants: Patients undergoing cardiac surgery without contraindications to aprotinin administration. Interventions: Patients were randomized to full-Hammersmith and half-Hammer smith dosing regimens of aprotinin and were further randomized to hemofiltr ation or no hemofiltration. Measurements and Main Results: Serum aprotinin levels were studied before C PB, 60 and 120 minutes into CPB, and at the end of CPB before protamine adm inistration. Each group experienced a decrease in serum aprotinin levels wi th the institution of CPB, attributable to hemodilution and redistribution of aprotinin outside of the vascular compartment. During CPB, aprotinin lev els declined further, but no significant difference was observed between pa tients who received hemofiltration and those who did not. Hematocrit values were significantly higher at the end of CPB in the hemofiltration groups. Patients receiving half-Hammersmith dosing regimens maintained aprotinin le vels throughout CPB, which have been shown to inhibit plasmin but were lowe r than levels previously shown to inhibit kallikrein. Conclusions Hemofiltration during CPB did not significantly alter serum apr otinin levels in patients receiving half-Hammersmith and full-Hammersmith d osing regimens of aprotinin. Copyright (C) 2000 by W.B. Saunders Company.