The value of rotation thromboelastometry to monitor disturbed perioperative haemostasis and bleeding risk in patients with cardiopulmonary bypass.

Rotation thromboelastometry (ROTEM) performed on whole-blood samples provides information on the contribution of fibrinogen and platelets to clot formation. Such measurements are believed superior to classical plasma coagulation measurements as a means of monitoring disturbed haemostasis. On-pump cardiac surgery is associated with high bleeding risk. The study objective was to obtain information on the frequency of abnormal values of ROTEM variables and to assess their value in estimating bleeding risk in such patients. We studied 150 patients undergoing elective on-pump cardiac surgery. We found a significant surgery-induced decrease in haemostatic potential, with more abnormal ROTEM values in intrinsically activated coagulation (up to 50%) than in extrinsically activated coagulation (up to 27%) or the maximum clot firmness in FIBTEM (10%), a test measuring the contribution of fibrinogen. All ROTEM variables tend to normalize within 14-18 h postoperatively. Best positive predictive values and specificity for a postoperative blood loss above 600 ml were found for the clot formation time in extrinsically activated coagulation (71%/94%) and the maximum clot firmness in FIBTEM (73%/95%); these values were superior to the activated partial thromboplastin time or prothrombin time (56%/72% and 43%/5%, respectively). There was no relation between preoperative or early postoperative ROTEM values and intraoperative bleeding. ROTEM recorded a benefit of administration of platelet concentrates or fresh-frozen plasma, particularly when given postoperatively, on haemostasis. In contrast, intraoperative administration of red blood cells impaired haemostasis. ROTEM can provide a more detailed diagnostic basis enabling a focused therapy to cardiac surgery patients with high bleeding risk.