DOSE-DEPENDENT EFFECT OF APROTININ ON RATE OF CLOT FORMATION

Forty-eight patients scheduled for elective cardiac surgery were rando mly assigned to receive aprotinin in the following doses: 0.2 mg kg(-1 ) (group A), 0.7 mg kg(-1) (group B), 1 mg kg(-1) (group C) and 1.4 mg kg(-1) (group D). Clot formation was analysed by thromboelastography immediately after induction of anaesthesia and again 30 min after admi nistration of aprotinin. Rate of clot formation was assessed using R ( reaction time = rate of initial fibrin formation), K (clot formation t ime = rate of fibrin build-up and cross linking) and angle of clot for mation (denoting speed at which solid clot forms). Strength of the clo t was assessed by maximal amplitude of clot formation (MA) and % lysis after 30 and 60 min. Significant reduction of R and K times and incre ase in angle of clot formation was observed in groups A and B. This ef fect was not apparent in the other groups. In group D, an increase in R time was noted. These findings indicate a dose-dependent effect of a protinin on rate of clot formation with an earlier clot formation at l ow doses.