Kinetic characterization of hemostasis in thermal injury.

Hemostasis has been characterized by kinetic measurements in 12 patients with severe burns. Survival and turnover of 51Cr-platelets, 131I-fibrinogen, and 125I-plasminogen were simultaneously measured in 10 patients within 24 hours of injury; the disappearance times were shortened in concert to approximately 20% of normal values, and platelet and fibrinogen turnover were increased to more than three times normal. Serial studies in five of these patients 3 and 5 weeks later showed progressive improvement in kinetic measurements ,but normal values were not achieved. Two additional patients with similar rates of consumption demonstrated localization of radiolabeled platelets and fibrinogen in the burn wound. Heparin therapy did not modify consumption significantly. Enhanced fibrinolysis was reflected by marked reduction in 125I-plasminogen survival, depletion of the plasma plasminogen levels, and elevated levels of fibrin degradation products. Initial low levels of platelets and fibrinogen were followed by compensatory elevations; factor V and prothrombin complex factors were depressed during the first five days, but factor VIII levels were not reduced. Thermal injury is characterized by marked and prolonged consumption within the wound of platelets, fibrinogen, and plasminogen that is not reversible by heparin. This process depletes hemostatic components and causes bleeding when the burn is massive or complications are severe.