Chapter 141 Coagulation Disorders Flashcards
Top three most common causes of DIC
Bacterial sepsis
Malignancy / Acute promyelocytic leukemia
Abruptio placentae, dead fetus syndrome, amniotic fluid embolism
Severe form of DIC affecting predominantly young children following viral and bacterial infections, presenting as thrombosis of extensive areas of the skin?
Purpura fulminans
Central mechanism of DIC?
Uncontrolled generation of thrombin
Proinflammatory cytokines that play central roles in mediating coagulation defects in DIC?
IL-6
TNF alpha
How is bleeding in chronic DIC different from acute DIC?
Discrete bleeding and restricted to skin or mucosal surfaces
The most sensitive test for DIC is:
Fibrin degradation products level
Fragmented red cells (schistocytes) in blood smear + elevated FDP
Most common differential diagnosis for DIC that present similarly?
Severe liver disease
Also at risk for bleeding
Thrombocytopenia - platelet sequestration, portal hypertension, hypersplenism
Elevated FDP - poor hepatic clearance
Low synthesis of coagulation factors
How to differentiate liver disease and DIC?
Lab parameters in liver disease do NOT change rapidly
Look for presence of portal hypertension or signs of underlying liver disease
Treatment of DIC with active bleeding or is at high risk for bleeding?
Transfusion of FFP and/or platelet concentrates
- in preparation for surgery or after chemotherapy
What cutoff platelet level in DIC requires replacement therapy?
Platelet <10,000-20,000
Low levels of fibrinogen <100mg/dl or brisk hyperfibrinolysis will require infusion of:
Cryoprecipitate
(fibrinogen, factor VIII, vWF)
10 U Cryo for every 2-3 U of FFP is sufficient to correct hemostasis
Treatment of purpura fulminans?
Heparin
During surgical resection of tumor or removal of dead fetus
Which patients with DIC benefit from antifibrinolytic drugs / tranexamic acid?
Acute promyelocytic leukemia
Chronic DIC
Giant hemangioma
Coagulation disorder caused by deficiency in Factor VIII?
Hemophilia A
Coagulation disorder caused by deficiency in Factor IX?
Hemophilia B
Isolated abnormal prothrombin time suggests deficiency of what factor?
Factor VII (Extrinsic pathway)
Prolonged aPTT indicates deficiency in Factors:
Factors VIII and IX (Hemophilia) or Factor XI (Intrinsic Pathway)
Prolongation of both PT and aPTT indicates deficiency in what factors?
Factors V, X, II (Thrombin) and Fibrinogen - Common Pathway
Differentiate deficiency vs presence of inhibitor using mixing tests
Addition of the missing protein to the plasma of a subject with an inhibitor does NOT correct the abnormal PTT and PT - if there is an inhibitor
One of the most common Hemophilia A mutations results from inversion of:
Intron 22 sequence
What test for coagulation is prolonged (isolated) in patients with Hemophilia?
Isolated prolongation of aPTT
Bleeding time and Platelet counts are normal
Most common bleeding manifestation in severe hemophilia
Recurrent hemarthroses - mainly knees elbows ankles shoulders hips
Acute hemarthroses due to bleeding may be painful, patients would tend to adopt a fixed position leading to this complication:
Muscle contractures
Hematomas into the muscle of patients with hemophilia may lead to:
Compartment syndrome
Recurrent bleeding in the joint (target joint) may need surgery
