Hematology

Anemia   Definition  Definition of anemia, according to World Health Organization criteria  Adult men : Blood hemoglobin concentration < 13 g/dL or Hematocrit < 39%  Adult women : Blood hemoglobin concentration < 12 g/dL or Hematocrit < 37%  Mechanism  Marrow production defects: Hypoproliferation  Reflects absolute or relative marrow failure in which the erythroid marrow has not proliferated appropriately for the degree of anemia  Can … Read more

Thrombocytopenia    Mechanism  Decreased bone marrow production  Marrow aplasia  Fibrosis  Infiltration with malignant cells  Cytotoxic drugs  Impair megakaryocyte proliferation and maturation  Sepsis- Viral and bacterial infections  Alcohol  B12/Folate deficiency  Increased splenic sequestration : Enlargement of spleen causes fraction of sequestered platelets to increase, decreasing the platelet count. Most common causes of splenomegaly are portal hypertension secondary to liver … Read more

Coagulopathy   Overview of hemostasis: Hemostasis is the process of blood clot formation at the site of vessel injury. It can be viewed as occurring in four phases: Initiation and formation of the platelet plug Propagation of the clotting process by the coagulation cascade Termination of clotting by antithrombotic control mechanisms Removal of the clot … Read more

ANTICOAGULATION IN ICU    Clotting cascade:      Warfarin:  For patients sufficiently healthy to be treated as outpatients, we suggest initiating VKA therapy with warfarin 10 mg daily for the first 2 days followed by dosing based on INR measurements rather than starting with the estimated maintenance dose  For patients taking VKA therapy with consistently … Read more

Disseminated Intravascular Coagulation  DIC, also called consumption coagulopathy, is a systemic process producing both thrombosis and hemorrhage. It consists of the following components:    Exposure of blood to procoagulants such as tissue factor and cancer procoagulant   Formation of fibrin within the circulation   Fibrinolysis   Depletion of clotting factors   End-organ damage  Purpura fulminans is a severe form of DIC resulting from thrombosis … Read more