Disseminated intravascular coagulation in sepsis

Disseminated intravascular coagulation (DIC) has been considered a rather rare syndrome characterized by severe bleeding. In fact, both of these beliefs are wrong. Bleeding is fairly rare in DIC. The clotting parameters are usually normal unless the DIC is fulminating. It is usually thought that fibrinogen may be low or absent in DIC. However, afibrinogenemia is rare. Fibrinogen is usually high in DIC because of the high rate of fibrinogen manufacture by the liver in response to stress. DIC is very common and most cases are never diagnosed. This is because it has been hard to find fibrin thrombi in autopsy cases and because acute severe bleeding is uncommon. The reason fibrin thrombi are rare may be because they have been lysed by endogenous fibrinolytic enzymes before the autopsy. The appearance of endogenous fibrinolytic response could be a defense mechanism to lyse the microclots of DIC. In fact, this response is often successful. This defense can be aided by the administration of plasminogen activators that will lyse the clots. Heparin has been used for the treatment of DIC but has proved useless and is, in fact, dangerous. This is because heparin will not dissolve clots and may actually promote platelet agglutination. Administration of plasminogen activators will actually prevent bleeding diathesis.