Recommendation #3: Compression stockings should be used routinely to prevent post-thrombotic syndrome, beginning within one month of diagnosis of proximal DVT and continuing for a minimum of one year after diagnosis.
Recommendation #4: There is insufficient evidence to make specific recommendations for types of anticoagulation management of VTE in pregnant women.
Recommendation #5: Anticoagulation should be maintained for three to six months for VTE secondary to transient risk factors and for more than 12 months for recurrent VTE. While the appropriate duration of anticoagulation for idiopathic or recurrent VTE is not definitively known, there is evidence of substantial benefit for extended-duration therapy.
Recommendation #6: LMWH is safe and efficacious for the long-term treatment of VTE in selected patients (and may be preferable for patients with cancer).
All of these seem reasonable and appropriate with a possible exception in the second recommendation. Using LMWH to treat patients diagnosed with PE in the outpatient setting is not well supported by data. The vast majority of trials involving the treatment of VTE with LMWH have been conducted on those with DVT; the number of patients in the trials with PE has been very small. The Food and Drug Administration has not approved LMWH for outpatient treatment of PE; LMWH is FDA approved in the outpatient setting only for the treatment of DVT. We know that the hemodynamic changes that can accompany PE may not occur for at least 24 hours. In addition, we now have data from the Nijkeuter study that point to dangers that may result from treating PE outside the hospital setting. At this time, we should treat PE with LMWH in the outpatient setting only with patients whose risk factors, clinical characteristics, and outpatient resources have been carefully scrutinized. TH