Dr. M.J. Bazos, MD Patient Handout

DISSEMINATED INTRAVASCULAR

COAGULATION

About Your Diagnosis
Hemostasis is the natural phenomenon of keeping the blood in a fluid state by means of keeping a fine balance between coagulation and anticoagulation. Pathologic processes that alter the normal balance among normal hemostatic determinants can lead to either inadequate hemostasis, which results in hemorrhage, or excessive hemostasis, which produces thrombosis. The process of coagulation involves a group of plasma proteins, platelets (blood cells that help blood to clot), and cells that line the walls of the blood vessels (endothelial cells). The coagulation proteins are normally in an inactive state. Activation of these proteins results in a cascade of events that lead to conversion of prothrombin to thrombin. Once it is generated, thrombin can initiate intravascular clotting, which causes consumption of thrombin-susceptible plasma proteins and formation of fibrin and platelet aggregates. Disseminated intravascular coagulation (DIC) is a phenomenon characterized by activation of procoagulants. This results in generation of thrombin and failure of the natural coagulation inhibitory mechanisms that neutralize thrombin. Fibrin strands in the vessels may develop and cause mechanical damage to red blood cells, producing microangiopathic hemolytic anemia and thrombocytopenia (low platelet count). DIC is not a disease; it is a phenomenon that results from many different diseases, such as infections, malignant diseases, trauma, and some obstetric problems. The incidence of DIC ranges from 12 to 49 patients per year at most medical centers. The possibility of DIC is usually considered when patients with infections, certain malignant diseases, open head injuries, and obstetric complications start bleeding from multiple sites. Spontaneous bruises, oozing from venipuncture sites, and spontaneous bleeding into the gastrointestinal tract, central nervous system, or lungs may occur. Abnormal results of laboratory tests usually consist of broken red blood cells, very small red blood cells, disfigured red blood cells, and decreased numbers of platelets on a peripheral blood smear. Results of tests of coagulation such as prothrombin time (PT), partial thromboplastin time (PTT), and thrombin time are prolonged. Levels of coagulation proteins such as fibrinogen and factors V and VIII are decreased. Platelet count is decreased. In most instances, changes in three or more laboratory values and a low platelet count are consistent with DIC. DIC is always secondary to another problem. The prognosis depends on the underlying condition.

Living With Your Diagnosis
DIC presents itself as generalized bleeding from different body sites, such as the gastrointestinal tract, lungs, and urinary tract. Shock (blood pressure that cannot be measured) out of proportion of bleeding occurs with severe forms of DIC. DIC causes disturbances in the fine balance between hemostasis and fibrinolysis. This results in formation of generalized microclots in the circulation. Red blood cells are injured mechanically during their passage through the microcirculation, resulting in microangiopathic hemolytic anemia. Coagulation factors and platelets are consumed in this generalized clotting process, resulting in deficiency of coagulation proteins and thrombocytopenia, which increases the tendency to bleeding.

Treatment
Management of the underlying condition remains the cornerstone of therapy for DIC. Patients with DIC are usually admitted to the hospital, and they are quite ill. Intensive replacement therapy is provided with blood products (packed red blood cells, platelets, and coagulation factors). Once the diagnosis of DIC is made and if there is any evidence of bleeding, blood products should be transfused to replace the deficient products accordingly. Heparin (an anticoagulant drug that inhibits the activated coagulation factors) is useful in certain cases of DIC. Transfusions of blood products are safe. The likelihood of transmission of infection is low. Fluid overload can develop if transfusions are too rapid. Patients can stop responding to platelet transfusions by making antibodies against the transfused platelets.

The DOs
• Adhere to any dietary restrictions depending on the underlying condition.
• Exercise as tolerated once your general condition improves.

The DON’Ts
• Do not take medications, such as aspirin or nonsteroidal anti-inflammatory drugs (NSAIDs), which can increase the tendency to bleed, without consulting your physician.
• Do not exercise until your condition stabilizes.

When to Call Your Doctor
• If you start bleeding from the nose or gums, notice bloody urine, or find spontaneous black and blue spots on your skin.

Websites:
MedWeb Hematology: http://www.gen.emory.edu/medweb.hematology.html
MedMark Hematology: http://medmark.bit.co.kr/hematol.html