Venous thromboembolism, whether associated with deep vein thrombosis, or DVT, or with pulmonary embolism, or PE, is a life-threatening medical problem that is difficult to prevent and treat. But early diagnosis and therapy for DVT and PE can save lives, given that more than 500,000 cases of DVT occur every year in the United States, and PE and other complications of venous thromboembolism account for 5 percent to 10 percent of all hospital deaths.
Seminar Probes Diagnosis, Treatment of DVT, PE
By Dennis Connaughton
• Chicago
10/5/2007
At an Oct. 4 seminar here on DVT and PE, Daniel Tambunan, M.D., assistant director of the Florida Hospital Family Practice Residency in Orlando, gave insights into how to best diagnose and treat these two forms of venous thromboembolism based on available scientific evidence and clinical guidelines.
Venous thromboembolism can result from any of the following factors:
Venous thromboembolism can result from any of the following factors:
- circulatory stasis due to immobility, congestive heart failure, obesity or venous obstruction;
- endothelial injury or surgical trauma (especially after hip or total joint replacement), parturition, infections, or heart-valve damage; and
- the presence of hypercoagulability related to factor V Leiden, oral contraceptive use, cancer, deficiencies of protein C or S, antithrombin III deficiency, elevated homocysteine levels, or impaired fibrinolysis.
Tambunan said that factor V Leiden is most often responsible for hypercoagulability and can be detected by a specific blood test. Both oral contraceptives and smoking increase the risk of venous thromboembolism 30-fold.
The risk of developing postsurgical venous thromboembolism varies according to the type of surgery; patient age; and other risk factors, such as recent myocardial infarction or stroke, varicose veins, intestinal bowel disease, presence of an indwelling femoral vein catheter, spinal cord injury, major trauma, cancer and a history of venous thromboembolism, Tambunan said.
Treatment options for DVT include unfractionated heparin; low-molecular-weight heparin, or LMWH; the pentasaccharide agent fondaparinux; placement of an inferior vena cava filter; intermittent pneumatic compression; and use of elastic stockings. The latest evidence indicates that LMWH is the preferred heparin to use for initial anticoagulation of patients with DVT, said Tambunan.
DVT is the most common cause of PE. Signs and symptoms of PE include tachypnea, chest pain, cough, tachycardia and dyspnea. Useful diagnostic studies include chest X-ray, electrocardiogram, arterial blood gas analysis, ventilation perfusion lung scan, spiral CT and pulmonary angiography.
Anticoagulation therapy for PE consists of IV or subcutaneous heparin initially, followed by oral warfarin. Heparin also is the most widely used prophylactic agent against PE.
Unfractionated heparin is the "forefather of treatment," Tambunan said, but it binds to proteins, has poor bioavailability and requires lab monitoring every six hours. LMWH has better bioavailability and requires no lab monitoring, he noted.
However, both unfractionated heparin and LMWH can cause severe thrombocytopenia. Tambunan recommended daily platelet monitoring between days 4 and 14 of therapy, especially in postoperative patients.
Clinicians should initiate warfarin therapy at a dose of 2 to 5 mg daily, he said, and frequently check the patient's international normalized ratio, or INR, after the initial dose. Clinicians then should titrate the dose to attain an INR of 2 to 3.
The risk of developing postsurgical venous thromboembolism varies according to the type of surgery; patient age; and other risk factors, such as recent myocardial infarction or stroke, varicose veins, intestinal bowel disease, presence of an indwelling femoral vein catheter, spinal cord injury, major trauma, cancer and a history of venous thromboembolism, Tambunan said.
Treatment options for DVT include unfractionated heparin; low-molecular-weight heparin, or LMWH; the pentasaccharide agent fondaparinux; placement of an inferior vena cava filter; intermittent pneumatic compression; and use of elastic stockings. The latest evidence indicates that LMWH is the preferred heparin to use for initial anticoagulation of patients with DVT, said Tambunan.
DVT is the most common cause of PE. Signs and symptoms of PE include tachypnea, chest pain, cough, tachycardia and dyspnea. Useful diagnostic studies include chest X-ray, electrocardiogram, arterial blood gas analysis, ventilation perfusion lung scan, spiral CT and pulmonary angiography.
Anticoagulation therapy for PE consists of IV or subcutaneous heparin initially, followed by oral warfarin. Heparin also is the most widely used prophylactic agent against PE.
Unfractionated heparin is the "forefather of treatment," Tambunan said, but it binds to proteins, has poor bioavailability and requires lab monitoring every six hours. LMWH has better bioavailability and requires no lab monitoring, he noted.
However, both unfractionated heparin and LMWH can cause severe thrombocytopenia. Tambunan recommended daily platelet monitoring between days 4 and 14 of therapy, especially in postoperative patients.
Clinicians should initiate warfarin therapy at a dose of 2 to 5 mg daily, he said, and frequently check the patient's international normalized ratio, or INR, after the initial dose. Clinicians then should titrate the dose to attain an INR of 2 to 3.
