Coagulation Review

The orthopaedic surgeon is required to manipulate the coagulation cascade and platelet function to minimize deep venous thrombosis and pulmonary embolism, without promoting excessive bleeding. Current management includes sequential compression devices, warfarin, unfractionated heparin, low-molecular-weight heparin, fondaparinux, direct oral anticoagulants, and aspirin. Larger clinical trials are needed to determine the best algorithm for testing pulmonary embolism or deep venous thrombosis after orthopaedic surgeries. Disseminated intravascular coagulation (DIC) is associated with a life-threatening illness, such as shock, severe trauma, sepsis and fat embolism, and results in consumption of clotting factors and platelets. Early diagnosis requires measurement of platelet count, D-dimer, prothrombin time, partial thromboplastin time, fibrinogen level, presence of fragmented erythrocytes on peripheral smear, and assessment of the underlying disease. DIC may result in both life-threatening hemorrhage and thrombosis compromising blood flow to various organs. The key management goal is to control underlying disease such as sepsis. Heparin-Induced Thrombocytopenia (HIT) is a consumptive immune-mediated process directed at platelets which requires immediate cessation of heparin products. It is critical to identify patients with Von Willebrand disease, Hemophilia, Inherited Thrombophilia, or Antiphospholipid antibody syndrome, and obtain appropriate consultation. Finally, the clinician should be alert to cytochrome enzyme impact precipitated by interactions between medications and anticoagulant, which may result in a clinically significant over—or under-coagulated state.