Effects of the propofol combination anesthesia on the intrinsic blood-clotting system

Fat emulsions can cause changes in blood-clotting and fibrinolysis. The aim of this study was to examine the relation between the use of the short-act ing hypnotic propofol and alteration of the blood clotting system, in a dou ble-blind randomized study, 36 patients with an aortocoronary bypass operat ion were given either midazolam/fentanyl or propofol/alfentanil. Eleven blo od samples were taken at fixed times pre-, intra- and postoperatively to de termine changes caused by the anesthetic agents on the hemostaseologic para meters during the whole operation. Perioperative blood pressures of both gr oups were measured at seven fixed points. From the beginning of the extraco rporeal circulation (ECC) to the end of the operation, the measured values of the factor XIIa- and kallikrein-like activity in the propofol group were significantly higher than those of the midazolam group. Also the values of the kallikrein inhibition capacity and the indicators of fibrinolysis (t-P A and D-dimers) suggest a stronger activation of the contact phase at the s tart of the recirculation and as a result of it a stronger fibrinolysis wit hin the propofol group. Besides, the hypotensive side-effect in the propofo l group was evident in contrast to the midazolam group. With this investiga tion, a correlation between the application of propofol/alfentanil, contact phase activation with activation of the kallikrein-kinin-bradykinin system and the observed hypotension can be set up. (C) 1999 Elsevier Science B.V. All rights reserved.