Am Fam Physician. 2007;76(11):1713-1717
Background: Venous thromboembolism (VTE) is a common condition and its incidence increases with age. Early and effective treatment of VTE is critical to prevent mortality and morbidity relating to pulmonary embolism (PE) and the postphlebitic syndrome that can complicate deep venous thrombosis (DVT). Snow and colleagues present clinical practice guidelines derived from a recent systematic review of the evidence completed by members of the Johns Hopkins University Evidence-based Practice Center. The American Academy of Family Physicians and the American College of Physicians formulated questions regarding the type, duration, and intensity of anticoagulation treatment for VTE.
Recommendations: The recommendations are summarized in the table on page 1717. The group also reviewed the incidence of PE and recurrent DVT after placement of vena cava filters. One randomized trial and one population-based study found a modest decrease in symptomatic PE after filter placement and anticoagulation, but also found an increase in recurrent DVT and no change in mortality. Many case series about different filter types have been reported, but their results are not generalizable. No conclusions about the role of vena cava filters without anticoagulation could be reached. There was insufficient evidence about the effectiveness of catheter-directed thrombolysis to make recommendations.
| LMWH is superior to unfractionated heparin for the initial treatment of DVT and should be used whenever possible. Either therapy is acceptable for the initial treatment of PE. (Level 1 evidence) | |
| LMWH is quickly and reliably therapeutic and is associated with a lower risk of major bleeding during initial therapy. | |
| Outpatient treatment of DVT with LMWH is safe and cost-effective in carefully selected patients in settings where required support services are available. (Level 1 evidence for DVT) | |
| Outpatient LMWH therapy may also be appropriate for PE. | |
| This recommendation cannot be generalized because of strict inclusion/exclusion criteria in the reviewed studies. | |
| Compression stockings can prevent postphlebitic syndrome and should be used routinely. (Level 1 evidence) | |
| Evidence supports starting compression stockings within one month of proximal DVT diagnosis and continuing for a minimum of one year. | |
| Evidence is insufficient to make anticoagulation recommendations for VTE in pregnant women. (Level 3 evidence on management of VTE in pregnancy) | |
| Anticoagulation should continue for three to six months after VTE caused by transient risk factors, and for more than 12 months for recurrent VTE. (Level 1 evidence suggests extended-duration anticoagulation [INR = 2 to 2.85] for idiopathic or recurrent DVT; Level 2 evidence exists to support only three months of anticoagulation for “provoked” VTE) | |
| LMWH is safe and effective for long-term anticoagulation and may be preferable for patients with cancer. (Level 1 evidence) | |