Fibrinogen, fibrin and its degradation products in drained blood after major orthopaedic surgery.

The aim of this study was to evaluate the fibrinogen enzymatic conversion in blood collected postoperatively from a surgical wound. Ten otherwise healthy patients (aged 11-28 years) in need of surgical treatment for thoracic scoliosis were included in the study. Arterial blood preoperatively and at wound closure were compared with samples of drained blood from the wound at closure and from a collection system for autologous transfusion 2.8 +/- 1.1 h later. There was a decrease in the fibrinogen content in arterial blood from 2.17 +/- 0.35 g/l to 1.23 +/- 0.42 g/l, which followed a 40% haemodilution estimated from the blood loss of 1.6 +/- 0.9 l during the operation. Drained blood contained high concentrations of D-dimer (85 +/- 53 mg/l from the wound and 121 +/- 47 mg/l from the collection system), but no clottable fibrinogen. The Western immunoblots all visualized the same patterns; in drained blood there were split-products mainly from cross-linked fibrin, in contrast to arterial blood which contained only normal fibrinogen. This indicates a strong fibrinolysis in the surgical wound after closure, with concentrations of fibrin degradation products that may impair local coagulation, and if infused, might interfere with general haemostasis.