February 7, 2012
New Guidelines Suggest DVT Prophylaxis Not Appropriate For All Patients
New evidence-based guidelines from the American College of Chest Physicians (ACCP) recommend considering individual patients' risk of thrombosis when deciding for or against the use of preventive therapies for deep vein thrombosis (DVT) and venous thromboembolism (VTE). Specifically, the Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines, published in the February issue of the journal CHEST, focus on risk stratification of patients, suggesting clinicians should consider a patient's risk for DVT/VTE and risk for bleeding before administering or prescribing a prevention therapy.
"There has been a significant push in health care to administer DVT prevention for every patient, regardless of risk. As a result, many patients are receiving unnecessary therapies that provide little benefit and could have adverse effects," said Guidelines Panel Chair Gordon Guyatt, MD, FCCP, Department of Medicine, McMaster University Faculty of Health Sciences, Hamilton, Ontario, Canada. "The decision to administer DVT prevention therapy should be based on the patients' risk and the benefits of prevention or treatment." To address this, the ACCP guidelines provide comprehensive risk stratification recommendations for most major clinical areas, including medical, nonorthopedic surgery, orthopedic surgery, pregnancy, cardiovascular disease, atrial fibrillation, stroke, pediatrics, and long-distance travel.
Although developing a travel-related DVT/VTE is unlikely in most cases, the guidelines note that for long-distance flights, several factors may increase an individual's risk of developing a DVT/VTE, including previous DVT/VTE or known thrombophilic disorder; malignancy; recent surgery or trauma; immobility; estrogen use or pregnancy; and sitting in a window seat. For travelers with an increased risk for travel-related DVT/VTE, the guidelines recommend frequent ambulation, calf muscle stretching, sitting in an aisle seat if possible, or the use of below-knee graduated compression stockings. Conversely, the guidelines suggest there is no definitive evidence to support that dehydration, alcohol intake, or sitting in economy class increases a patient's risk for developing a DVT/VTE resulting from long-distance flights.
ASPIRIN AND NEW THERAPIES FOR DVT/VTE PREVENTION
The guidelines also provide recommendations related to the use of new or potential therapies for the prevention and treatment of DVT/VTE. Although aspirin is not a new therapy for the prevention of DVT/VTE, previous ACCP guidelines recommended against using aspirin as the single agent for prophylaxis in any surgical population. In the current edition, the ACCP has revised this recommendation and indicates aspirin is an option–although not typically the agent of choice–for the prevention of DVT/VTE in major orthopedic surgery.
"Although we are not recommending aspirin as the optimal DVT/VTE prophylaxis, we have reviewed the existing evidence and concluded that aspirin is an acceptable option in some instances where preventive therapy is needed," said guideline co-author Mark Crowther, MD, Department of Medicine, McMaster University, Hamilton, Ontario, Canada. In regard to new oral anticoagulants, guideline authors recognize the recent clinical trials of apixaban and rivaroxaban, both direct factor Xa inhibitors, and dabigatran etexilate, a direct thrombin inhibitor, and offer recommendations for the new agents for select clinical conditions, including atrial fibrillation and orthopedic surgery.
INNOVATIONS IN ANTITHROMBOTIC GUIDELINES
The Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines include innovations that have significantly impacted the more than 600 recommendations for the prevention, diagnosis, and treatment of thrombosis. Two key advances are the more explicit and quantitative consideration of patient values and preferences and restriction of outcomes to only those deemed to be important for the patient. The latter innovation results in different interpretation of the body of evidence in thrombosis prevention that has previously focused on the detection of asymptomatic thrombosis by surveillance methods.
Guideline authors also took a more critical look at the overall process of guideline development, providing more methodologically sophisticated scrutiny of all available evidence. "The evidence review for the new guidelines was more rigorous than ever before, and our method for grading research studies has become even more stringent," said guideline co-author David Gutterman, MD, FCCP, ACCP Immediate Past President, Cardiovascular Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin. "We believe that the objective rigorous application of the science of guideline development will ultimately best serve our patients."
The guidelines are endorsed by the following medical associations: the American Association for Clinical Chemistry, American College of Clinical Pharmacy, American Society of Health-System Pharmacists, American Society of Hematology, International Society of Thrombosis and Hemostasis, and the American College of Obstetrics and Gynecology (pregnancy article only).
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