INTRAOPERATIVE CLOTTING FACTOR DILUTION AND ACTIVATED HEMOSTASIS IN CHILDREN WITH EWINGS-SARCOMA OR OSTEOSARCOMA - A PROSPECTIVE LONGITUDINAL-STUDY

Background. The study was designed to evaluate prospectively intraoper ative changes in coagulation and fibrinolysis in young patients with E wing's sarcoma (n=12) or osteosarcoma (n=12) who underwent major surge ry, and to relate them to hematocrit (HCT) readings. Materials and Met hods. Blood samples (von Willebrand factor, fibrinogen, antithrombin I II, protein C, plasminogen, t-PA ag, PAI 1 activity, F1+2, D-dimer, PA P) were obtained immediately prior to starting anesthesia, two and fou r hours later, immediately after surgery and on the first postoperativ e day. Intra- and postoperative hemostatic parameters were adjusted to preoperative HCT readings. Results. Major surgery induced dilution co agulopathy due to blood product transfusion to support the patient's v ascular volume. Postoperatively, VWF (0.01) and fibrinogen (0.007) wer e 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 onl y minor deviations. T-PA (0.012) and PAI 1 (0.001) rose during the ope ration and normalized on the first postoperative day. Within 36 hours of the initial operation, six of the 24 patients (25%) returned to sur gery to stop severe hemorrhage. Conclusions. These findings indicate t hat hemostatic parameters may be useful when monitoring surgery- and t ransfusion-induced hemostatic imbalance. Furthermore, the significant differences between the HCT-uncorrected concentration of the various p lasma proteins clearly demonstrated the need to use HCT correction fac tors which may influence the necessity for and/or the frequency of sub stitution therapy with protein concentrates.