Summary
The hemostatic effect of two low molecular weight heparin fractions and of one unfractionated
heparin preparation administered subcutaneously b. i. d. was examined in 6 healthy
subjects and in 53 patients after major abdominal surgery. Among other tests platelet
count, prothrombin time, fibrinogen, β-thrombo- globulin, antithrombin, antiplasmin,
FPA and F-CB 3 related antigen, as well as various heparin activities, were repeatedly
determined pre- and postoperatively. Under all tested conditions the low molecular
weight fractions induced higher heparin levels, both in terms of anti-Xa and of anti-thrombin
activity. No further significant differences of the laboratory results between the
treatment groups were documented. Total blood loss measured at the first postoperative
day was higher in patients with malignancy and negatively correlated with antithrombin
and antiplasmin levels, while no relation was observed with the heparin activities
and the other tested parameters. Whereas evidence for a hemorrhagic property of the
tested low molecular weight heparin fractions was found, a particular mechanism underlying
this effect could not be identified.
Keywords
Thrombosis prophylaxis - Low molecular weight heparin - Postoperative hemostasis -
Bleeding complications
