Abstract 1669: Aprotinin Concentration Varies According To Cardiopulmonary Bypass Conditions
Background: Aprotinin continues to be widely used in pediatric cardiac surgery although questions regarding renal toxicity in adults have been raised. This study tested the hypothesis that aprotinin concentration in plasma varies according to cardiopulmonary bypass conditions (temperature, flow rate).
Methods: Twenty-four piglets (mean weight, 13kg) received aprotinin initial dose 30,000 KIU/kg, maintenance infusion 10,000 KIU/kg/h, with CPB prime 30,000 KIU/kg. Aprotinin infusion was terminated at end of CPB and stopped during hypothermic circulatory arrest (HCA). Piglets were randomly assigned to four groups (6 animals per group) according to CPB conditions; HCA: a 60-minute period of HCA at15° LF:10 ml/kg/ min low-flow CPB at 25° FF: full flow CPB at 37°, and Control without CPB at 37°. Blood samples were collected at 7 time points: after induction of anesthesia (baseline), after initial dose, 5, 50 and 115 min after start of CPB, just before end of CPB and 30 min after CPB. Plasma aprotinin levels were determined by modified functional assays using plasma kallikrein.
Results: Control group had significantly lower aprotinin levels at each point after start of CPB than all other groups with CPB (p<0.003). Aprotinin levels at reperfusion phase were significantly higher in HCA and LF groups than in FF group (p<0.001). Aprotinin levels remained elevated in HCA group after reperfusion.
Conclusion: Plasma aprotinin concentrations vary according to bypass conditions. Recently reported renal and neurological complications with aprotinin use during CPB may reflect excessive dosing and emphasize the need for a method of real-time monitoring of aprotinin concentration.