Seminars in thrombosis and hemostasis
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Semin. Thromb. Hemost. · Jul 1985
ReviewHemostasis defects associated with cardiac surgery, prosthetic devices, and other extracorporeal circuits.
This discussion has provided a review of the available literature regarding alterations of hemostasis associated with CPB surgery, the use of prosthetic devices, and apheresis. The key to prevention of CPB hemorrhage is to obtain an adequate preoperative workup. Of extreme importance is an adequate history with respect to bleeding tendencies and thrombotic tendencies in both the patient and the family; of equal importance is a careful history regarding the use of drugs affecting hemostasis, especially drugs known to interfere with platelet function. ⋯ In addition to the usual prothrombin time, partial thromboplastin time, and platelet count, a standardized template bleeding time (and thrombin time in patients subjected to CPB) should be performed. The use of these simple testing modalities will guard against significant defects in vascular and platelet function. Most instances of nontechnical surgical and cardiovascular surgical hemorrhage are due to several well-defined defects in hemostasis that should be readily controlled if approached in a logical manner as a team effort among surgeons, pathologists, and hematologists.
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A number of hemostasis parameters were studied in a total of 63 patients undergoing cardiopulmonary bypass (CPB) for open heart surgery. In 33 patients fibrinogen, Factors II, V, VIII:C, X, XI, antithrombin, plasminogen, alpha 2-antiplasmin, and platelet counts were assayed before surgery, during maximal hypothermia, at the end of the bypass procedure, before and after protamine sulfate infusion, in the intensive care unit, and 48 hours postoperatively. All factors assayed decreased markedly when the patients were placed on the bypass machine, the drop fairly well paralleling the decrease in hematocrit. ⋯ Twenty-four hours postoperatively the volumes were normal again. Platelet aggregation studies were performed on a whole blood aggregometer using two concentrations of ADP, collagen, and ristocetin as aggregation inducers. A significant decrease in aggregability was seen when the patients were connected to the CPB apparatus.(ABSTRACT TRUNCATED AT 400 WORDS)