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Disseminated Intravascular Coagulation

August 10th 2011

Disseminated Intravascular Coagulation (DIC) By Prof. Rifaat Al-Shimmy, Al-azhar U.Definition of DIC A pathological condition associated with activation of both: • Coagulation system and • Fibrinolytic one It should be considered as a secondary phenomena of an underlying disease as...Common Obstetric ConditionsAssociated with: • Inadequate replacement of blood loss • Pre-eclampsia-Eclampsia…HELP syndrome • Ante partum hge (abruption placenta and P.P.) • I U F D when prolonged more than 4 weeks • Blood transfusion when massive or incompatible • Septic abortion or massive tissue injury • Amniotic fluid embolism • Saline I U infusionMassive Transfusion Is defined as the replacement of a patient's total blood volume in less than 24 hours,or as the acute administration of more than half the patient's estimated blood volume per hour. DIC is commonly a consequence of delayed or inadequate resuscitation page_break@DIC: Is it Predictable? • It can probably be predicted in all the previously mentioned high risk groups, except amniotic fluid embolism, as it is an unpredictable condition. • However, in AFE, DIC it always occurs only after resuscitation from the primary shocked state. page_break@Is it Preventable? • It can be avoided in most cases by proper ‘in time’ resuscitation and management of the underlying disease in proper time, e.g. Pre-eclampsiaPathogenesis • The most accepted theory is the Cascade theory in which there is activation of both Extrinsic and Intrinsic pathways leading to activation of factor xa leading to formation of thrombin from prothrombin to form fibrin from fibrinogen • With associated activation of fibrinolytic system as a protective mechanism.Pathophysiology, continued Pregnancy is considered as a hypercoagulable state by: • An increase in all coagulation factors except FXI/FXIII. Fibrinogen which increases to 400-650mg/dl in late pregnancy. • The fibrinolytic system is depressed during normal pregnancy and labor but returns to normal one hour after delivery of the placenta.Pathophysiology, continued Decrease in platelets count is a result of: 1. Consumption 2. Aggregation of plateletsPathophysiology, continued • So DIC is a state of increase thrombin activity at first, followed by increased fibrinolytic activity, leading to… • consumption of coagulation factor (source of old name consumptive coagulopathy) and the formation of FDP impairing homeostasis.Pathophysiology, continued • Deposition of fibrin in organs and tissues may lead to ischemic tissue damage. • The decreased number of platelets and elevated FDP increase the problem of homeostasis.Symptoms of DIC It is variable according to the cause, the presentation of the primary cause with: • Generalized or localized hemorrhage • Peticheae • Thromboembolc manifestation, organ failure as: liver, lung, kidneys, brain and frank gangrene have been described. • Chronic DIC, (that occurs with IUFD) may be asymptomatic.Diagnosis Although the definite diagnosis is only by histological finding of fibrin deposits, there are many indirect tests as: • Bedside clot retraction test • Skin puncture test, measure clotting time (fibrinogen) • D. Diamer           (90%) • Platelets count   (90%) • FDP                      (90%) • Thrombin time   (80%) • PTT and PT        (60%)Bedside Clot Retraction Tes(CT) • It simply tests the clotting time - a test of decreased fibrinogen • 2 ml blood in test tube - no clot formed but if occurs it is prolonged, soft and not retracted after half an hour, leaving a clot volume more than serum volume. (the clot doesn't retract)Skin Puncture Test (bleeding time) • Prolonged skin puncture ooze is observed when the platelets count is less than 100,000/ul • Continuous bleeding at puncture site occurs when pl count is less than 30,000 /ulOther laboratory tests • Platelets count decreases in 90% of cases (count less than 100,000/dl) • PT, which measures the time required by extrinsic pathway, elevated in 80% of DIC • PPT which measure the time required by intrinsic pathway - not helpful. • Thrombin time elevated in 80% of casesOther laboratory tests • Fibrinogen level/ less than150mg. This is present in 70% of cases. • Fibrin split product >40ug/dl, 90% of cases • D-Diamer - an antigen formed as a result of plasmin digestion, elevated in 90%of cases.Treatment of DIC • Essentially treat the underlying cause. In most cases prompt termination of pregnancy is required. • Supportive therapy should be directed to the correction of shock, acidosis and tissue ischemia. • Cardiopulmonary support including inotropic therapy, blood transfusion and assisted ventilationGuidelines by the Scottish Executive Committee of the RCOG

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