Results of low-dose heparin prophylaxis of venous thrombosis considering plasma heparin and anti-thrombin III concentration.

Abstract

<h2>Abstract</h2> Application of low-dose heparin results in a reduction of factor Xa without a prolongation of partial thromboplastin time above normal range. A minor prolongation of thrombin time does not increase the risk of bleeding. Anti-thrombin III activity is not reduced, although the immunologically determined anti-thrombin III is slightly lowered due to formation of complexes with heparin. A correlation is found between body weight and heparin dosage, rendering a body weight-related dosis superior. If nevertheless a schematic dosage is preferred there should be differentiated between a smaller dosage for patients with a body weight up to 65 kg and a larger one for patients heavier than that. As the effect of heparin, applied subcutaneously, lasts for more than 12 hours, two injections per day are sufficient. Due to the differences in the release of platelet factor 4 variations will also be found in low-dose heparin therapy. Therefore a control of partial thromboplastin time and thrombin time is advisable in order to prevent complications.