Thromboelastography for monitoring prolonged hypercoagulability after major abdominal surgery

Despite clinical and laboratory evidence of perioperative hypercoagulabilit y, there are no consistent data evaluating the extent, duration, and specif ic contribution of platelets and procoagulatory proteins by in vitro testin g. We tested the hypothesis that the parallel use of standard and abciximab -cytochalasin D-modified thromboelastography (TEG(R)) can assess 7 days' po st-operative hypercoagulability and can estimate the independent contributi on of procoagulatory proteins and platelets. Thromboelastograms were perfor med before surgery, at the end of surgery, 6 h after surgery, and on postop erative days 1, 2, 3, and 7; they were analyzed for the reaction time and t he maximal amplitude (MA). We calculated the elastic shear modulus of stand ard MA (G(t)) and modified MA (G(c)), which reflect total clot strength and procoagulatory protein component, respectively. The difference was an esti mate of the platelet component (G(p)). There was a 10% perioperative increa se of standard MA, corresponding to a 50% increase of G(t) (P < 0.0001) and an 86%-90% contribution of the calculated G(p) to G(t). We conclude that s erial standard and modified thromboelastography may reveal prolonged postop erative hypercoagulability and the independent contribution of platelets an d procoagulatory proteins to clot strength.