disseminated

disseminated intravascular coagulation (DIC) a bleeding disorder characterized by abnormal reduction in the elements involved in blood clotting due to their use in widespread intravascular clotting. It may be a secondary complication of any of numerous obstetrical, surgical, infectious, hemolytic, and neoplastic disorders, all of which activate in some way the intrinsic coagulation sequence. Paradoxically, the intravascular clotting ultimately produces hemorrhage because of rapid consumption of fibrinogen, platelets, prothrombin, and coagulation factors V, VIII, and X. Because of this pathology, the condition is sometimes called defibrination syndrome or consumption coagulopathy.

There may be signs and symptoms related to tissue hypoxia and infarction caused by the many microthrombi, but DIC is more often seen as an acute or chronic hemorrhagic disorder related to excessive and diffuse depletion of the elements needed for hemostasis. DIC should be suspected in any patient who has an unexplained tendency toward bleeding, and is suffering from one of the following types of clinical conditions: (1) those that introduce coagulation-promoting factors into the circulation, as in abruptio placentae, retained dead fetus, amniotic fluid embolism, metastatic carcinoma of the pancreas, lung, stomach, or prostate, and acute promyelocytic leukemia; (2) those that lead to stagnant blood flow, as in hypotension and polycythemia; (3) those accompanied by widespread endothelial injury, as in severe burns, trauma, heat stroke, and surgery, particularly surgery involving extracorporeal circulation; (4) various types of infections and bacteremias; and (5) snake bite and fat embolism.

The tendency toward excessive bleeding can appear suddenly and, with little warning, rapidly progress to severe or even fatal hemorrhage. Signs of DIC include continued bleeding from a venipuncture site, occult and internal bleeding, and, in some cases, profuse bleeding from all orifices. Other less obvious and more easily missed signs are generalized sweating, cold and mottled fingers and toes (due to capillary thrombi and hypoxia), and petechiae.

The diagnosis of DIC is confirmed by laboratory tests that show prolonged thrombin time, prothrombin time, and partial thromboplastin time; depressed platelet count and fibrinogen count; elevated fibrin split products (FSP); and a strongly positive protamine sulfate test. Assays for coagulation factors are commonly done to diagnose DIC; if the condition is present, the levels of these factors are reduced.

Extreme care must be taken to prevent complications related to bleeding. Injections should be avoided. Venipunctures should be limited whenever possible.

Treatment of DIC consists of replacement of the inadequate blood products and correction, when possible, of the underlying cause. When the primary disease cannot be treated, intravenous injections of heparin may inhibit the clotting process and raise the level of the depleted clotting factors. However, heparin therapy remains controversial as it can itself cause bleeding.

Scattered or distributed throughout the body. Lyme disease that has progressed beyond the stage of localized EM is said to be disseminated.