THE EFFECT OF LOW-DOSE HEPARIN ON HYPERCOAGULABILITY FOLLOWING ABDOMINAL AORTIC-SURGERY

The effect of low-dose heparin on postoperative hypercoagulability was assessed using thrombelastography (TEG) in eighteen patients undergoi ng elective abdominal aortic surgery. patients received unfractionated heparin 5000IU bd SC commencing on the first postoperative day. Nativ e whole blood TEG was performed preoperatively and on day two postoper atively, A heparinase-modified TEG was performed at the same time as t he native whole blood TEG on day two. There were no significant change s in the postoperative native whole blood TEG variables (r, K, alpha, MA) relative to preoperative controls. In contrast, there were signifi cant decreases in r and K, and increases in alpha in the heparinase-mo dified TEGs postoperatively (P<0.01), There were significant differenc es between the postoperative native whole blood and heparinase-modifie d TEGs for all TEG variables (P<0.01). The results indicate that low-d ose heparin reduces postoperative hypercoagulability following abdomin al aortic surgery as assessed by thrombelastography.