- The risk of venous thromboembolism (VTE) is related to several easily identifiable factors, including age, major surgery (particularly orthopedic procedures of the lower extremities), previous VTE, trauma, malignancy, prolonged immobility or limb paralysis, and hypercoagulable states.
- The diagnosis of VTE should be confirmed by objective testing.
- At the time of hospital admission, all patients should receive prophylaxis against VTE that corresponds to their level of risk. Prophylaxis should be continued throughout the period of risk.
- In the absence of contraindications, the treatment of VTE should initially include a rapid-acting anticoagulant (e.g., unfractionated heparin, low-molecular-weight heparin, fondaparinux, or rivaroxaban). If the patient is transitioned to warfarin therapy, the rapid-acting anticoagulant should be overlapped with warfarin for at least 5 days and until the patient's international normalized ratio is greater than 2.
- Most patients with an uncomplicated deep vein thrombosis (DVT), with or without pulmonary embolism (PE), can be safely treated as an outpatient.
- Emerging anticoagulants such as rivaroxaban may mark a significant advancement in the treatment of VTE.
- Anticoagulant therapies require meticulous and systematic monitoring as well as ongoing patient education.
- Bleeding is the most common adverse effect associated with anticoagulant drugs. A patient's risk of major hemorrhage is related to the intensity and stability of therapy, concurrent drug use, history of prior bleeding, prior history of stroke, renal or hepatic impairment, thrombocytopenia, recent surgery or trauma, and increasing age.
- Anticoagulation therapies for VTE should be continued for a minimum of 3 months. The duration of anticoagulation therapy should be based on the patient's risks of VTE recurrence and major bleeding, and preference regarding continued treatment.
On completion of the chapter, the reader should be able to:
Describe the processes of hemostasis and thrombosis—specifically the role of the vascular endothelium, platelets, coagulation cascade, and thrombolytic proteins.
Discuss the pathogenesis of deep vein thrombosis (DVT) and pulmonary embolism (PE).
Stratify a patient's risk of developing venous thrombosis.
Recognize the signs and symptoms of DVT and PE.
Compare and contrast the mechanisms of action of anticoagulant drugs: warfarin, unfractionated heparin (UFH), the low-molecular-weight heparins (LMWHs), fondaparinux, rivaroxaban, apixaban, and dabigatran.
State at least two potential advantages of the LMWHs and fondaparinux over UFH.
Analyze the advantages and disadvantages of anticoagulant drugs in terms of their pharmacokinetic and pharmacodynamic properties.
Identify factors that place a patient at high risk of bleeding while receiving anticoagulant drugs.
Formulate a prevention strategy for a patient at high risk for DVT consistent with clinical practice guidelines.
Formulate a treatment plan for a patient who develops a DVT or PE consistent with clinical practice guidelines.
Identify anticoagulant drug–drug and drug–food interactions and state their potential impact on a patient's coagulation status.
Select and interpret laboratory test(s) commonly used to monitor anticoagulant drugs.
Develop a comprehensive education plan for a patient who is receiving an anticoagulant drug.
Formulate an opinion regarding the potential role of rivaroxaban, apixaban, and dabigatran in the prevention and treatment of venous thromboembolism.