March 19, 2014

DynaMed EBM Journal Volume 9, Issue 12

DynaMed Weekly Updates

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Physicians: .25 AMA PRA Category ICreditsTM

Family Physicians: .25 Prescribed credits

Nurse Practitioners: .25 Contact hours

Release Date: March 19, 2014

Expiration Date: March 19, 2015

Estimated Completion Time: 15 minutes

There is no fee for this activity.

To Receive Credit

In order to receive your certificate of participation, you should read the information about this activity, including the disclosure statements, review the entire activity, take the post-test, and complete the evaluation form. You may then follow the directions to print your certificate of participation. To begin, click the CME icon at the end of the article.

Program Overview

Learning Objectives

Upon successful completion of this educational program, the reader should be able to:
1. Discuss the significance of this article as it relates to your clinical practice.
2. Be able to apply this knowledge to your patient's diagnosis, treatment and management.

Faculty Information

Alan Ehrlich, MD - Assistant Clinical Professor in Family Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA; Senior Deputy Editor, DynaMed, Ipswich, Massachusetts, USA

Michael Fleming, MD, FAAFP - Assistant Clinical Professor of Family Medicine and Comprehensive Care, LSU Health Science Center School of Medicine, Shreveport, Louisiana, USA; Assistant Clinical Professor of Family Medicine, Department of Family and Community Medicine, Tulane University Medical School, New Orleans, Louisiana, USA; Chief Medical Officer, Amedisys, Inc. & Antidote Education Company


Dr. Ehrlich, Dr. Fleming, DynaMed Editorial Team members, and the staff of Antidote Education Company have disclosed that they have no relevant financial relationships or conflicts of interest with commercial interests related directly or indirectly to this educational activity.

No commercial support has been received for this activity.

Accreditation Statements

ACCME: This activity has been planned and implemented in accordance with the Essential Areas and policies of the Accreditation Council for Continuing Medical Education through the joint sponsorship of Antidote EducationCompany and EBSCO Publishing. Antidote is accredited by the ACCME to provide continuing medical education for physicians. Antidote Education Company designates this enduring activity for a maximum of 0.25 AMA PRA Category 1 CreditsTM. Physicians should only claim credit commensurate with the extent of their participation in the activity.

AAFP: Enduring Material activity, DynaMed EBM Focus, has been reviewed and is acceptable for up to 13 Prescribed credits by the American Academy of Family Physicians. AAFP certification begins March 7, 2012. Term of approval is for one year from this date with the option of yearly renewal. Each EBM Focus is worth .25 Prescribed credits. Physicians should claim only the credit commensurate with the extent of their participation in the activity.

AANP: This program is approved for 0.25 contact hour of continuing education by the American Academy of Nurse Practitioners.

Program ID: 1304159T


Last week 540 journal articles were evaluated via DynaMed's Systematic Literature Surveillance and summaries of 270 articles were added to DynaMed content.

Based on criteria for selecting "articles most likely to change clinical practice," one article was selected by the DynaMed Editorial Team.

This week, the DynaMed EBM Focus highlighted evidence from a new randomized trial evaluating compression stockings for prevention of post-thrombotic syndrome after first-time proximal deep vein thrombosis. The findings of this trial were not consistent with previous trials, which were smaller and of lower methodologic quality. Further, they do not support current recommendations by the American College of Chest Physicians, which based their recommendation on these previous trial results.

Our initial message focused on this inconsistency of clinical evidence. However, after further reviewing the quality of the individual components included in our evidence synthesis, we have revised our conclusion to state that elastic compression stockings may not show benefit in this patient population. Please see below the revised EBM Focus conclusion, and refer to the Deep vein thrombosis (DVT) and Venous insufficiency topics in DynaMed for further information.

The DynaMed Editorial Team

Elastic Compression Stockings May Not Decrease Risk of Post-Thrombotic Syndrome After First-Time Proximal Deep Vein Thrombosis
Reference: Lancet 2014 Mar 8;383(9920):880 (level 2 [mid-level] evidence)

Post-thrombotic syndrome is a chronic disorder affecting 40%-48% of patients during the first 2 years after acute symptomatic deep venous thrombosis (DVT) (Ann Intern Med 2008 Nov 18;149(10):698). The American College of Chest Physicians currently recommends wearing compression stockings with 30-40 mm Hg pressure at the ankle for 2 years to reduce the risk of developing post-thrombotic syndrome (ACCP Grade 2B, Chest 2012 Feb;141(2 Suppl):e419S, full-text). However, the data supporting this recommendation are inconsistent, and come from small randomized trials without blinding. A new double-blind randomized trial compared compression stockings to sham stockings (without therapeutic compression) in 806 patients with proximal DVT.

Patients (mean age 55 years) with first-time symptomatic proximal DVT were randomized to elastic compression stockings with ankle pressure 30-40 mm Hg vs. sham stockings with ankle pressure < 5 mm Hg. They were instructed to wear their assigned stockings daily during waking hours for 2 years. Stockings were worn as pairs applied within 2 weeks of presentation with DVT, and were replaced every 6 months, or earlier if stockings were torn or a patient’s leg size had changed. Patients with a short expected lifespan (< 6 months) and those who had received initial treatment with thrombolytic therapy were excluded from the trial. Post-thrombotic syndrome was assessed using Ginsberg's criteria (leg pain and swelling for ≥ 1 month). The development of post-thrombotic syndrome was assessed every 6 months.

The overall proportion of patients adhering to use of stockings ≥ 3 days/week was 86.4% at 1 month (83.8% with compression vs. 89.1% with sham) and 55.6% at 2 years (56.1% with compression vs. 54.8% with sham). After excluding 3 patients found to be ineligible after randomization, 803 patients were included in the primary efficacy analysis. The cumulative incidence of post-thrombotic syndrome was 14.2% with elastic compression stockings vs. 12.7% with sham stockings (not significant). These results were consistent in a per-protocol analysis evaluating only patients reporting any stocking use on ≥ 2 visits and using stockings ≥ 3 days/week at those visits. There were no significant between-group differences in post-thrombotic syndrome severity, frequency of ipsilateral leg ulcers, or quality of life scores.

The findings of this new trial do not support routine use of compression stockings following acute DVT for prevention of post-thrombotic syndrome. These new results are not consistent with previous findings, although this is the largest trial to date to evaluate compression stockings in this patient population, and the only one thus far to have a blinded assessment using a sham stocking as a comparator. The adherence to compression stockings in this trial is reported to be lower than those observed in previous trials, although differences in methods used to measure adherence make any direct comparisons difficult. In addition, stockings may lose their elasticity after about 3 months (Circulation 2004 Oct 19;110(16):e445 full-text), so the decision to replace stockings every 6 months in this new trial may have resulted in suboptimal therapeutic compression.

For more information see the Venous insufficiency and Deep vein thrombosis (DVT) topics in Dynamed.

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DynaMed Careers

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