Intraoperative clotting factor dilution and activated hemostasis in children with Ewing's sarcoma or osteosarcoma: a prospective longitudinal study

Department of Pediatric Hematology and Oncology, University Hospital Munster, Germany.

BACKGROUND. The study was designed to evaluate prospectively intraoperative changes in coagulation and fibrinolysis in young patients with Ewing's sarcoma (n = 12) or osteosarcoma (n = 12) who underwent major surgery, and to relate them to hematocrit (HCT) readings. MATERIALS AND METHODS. Blood samples (von Willebrand factor, fibrinogen, antithrombin III, protein C, plasminogen, t-PA ag, PAI 1 activity, F1+2, D-dimer, PAP) were obtained immediately prior to starting anesthesia, two and four hours later, immediately after surgery and on the first postoperative day. Intra- and postoperative hemostatic parameters were adjusted to preoperative HCT readings. RESULTS. Major surgery induced dilution coagulopathy due to blood product transfusion to support the patient's vascular volume. Postoperatively, VWF (0.01) and fibrinogen (0.007) were found to be significantly enhanced, whereas antithrombin III levels were significantly (0.007) decreased. D-dimer formation showed a clear, significant (0.0019) rise two hours after skin incision and remained elevated through the first postoperative day. F1+2 and PAP showed only minor deviations. T-PA (0.012) and PAI 1 (0.001) rose during the operation and normalized on the first postoperative day. Within 36 hours of the initial operation, six of the 24 patients (25%) returned to surgery to stop severe hemorrhage. CONCLUSIONS. These findings indicate that hemostatic parameters may be useful when monitoring surgery- and transfusion-induced hemostatic imbalance. Furthermore, the significant differences between the HCT-uncorrected concentration of the various plasma proteins clearly demonstrated the need to use HCT correction factors which may influence the necessity for and/or the frequency of substitution therapy with protein concentrates.