0
We're unable to sign you in at this time. Please try again in a few minutes.
Retry
We were able to sign you in, but your subscription(s) could not be found. Please try again in a few minutes.
Retry
There may be a problem with your account. Please contact the AMA Service Center to resolve this issue.
Contact the AMA Service Center:
Telephone: 1 (800) 262-2350 or 1 (312) 670-7827  *   Email: subscriptions@jamanetwork.com
Error Message ......
Original Investigation | Pacific Coast Surgical Association

Thrombelastography-Based Dosing of Enoxaparin for Thromboprophylaxis in Trauma and Surgical Patients A Randomized Clinical Trial ONLINE FIRST

Christopher R. Connelly, MD1; Philbert Y. Van, MD1; Kyle D. Hart, MS2; Scott G. Louis, MD1; Kelly A. Fair, MD1; Anfin S. Erickson, BA1; Elizabeth A. Rick, BS1; Erika C. Simeon, BA1; Eileen M. Bulger, MD3,4; Saman Arbabi, MD3,5; John B. Holcomb, MD6; Laura J. Moore, MD6; Martin A. Schreiber, MD1
[+] Author Affiliations
1Division of Trauma, Critical Care, and Acute Care Surgery, Department of Surgery, Oregon Health and Science University, Portland
2Department of Surgery, Oregon Health and Science University, Portland
3Department of Surgery, University of Washington, Seattle
4Harborview Medical Center, University of Washington, Seattle
5Harborview Injury Prevention and Research Center, University of Washington, Seattle
6Center for Translational Injury Research, Division of Acute Care Surgery, Department of Surgery, The University of Texas Medical School, Houston
JAMA Surg. Published online August 03, 2016. doi:10.1001/jamasurg.2016.2069
Text Size: A A A
Published online

Importance  Prophylactic enoxaparin is used to prevent venous thromboembolism (VTE) in surgical and trauma patients. However, VTE remains an important source of morbidity and mortality, potentially exacerbated by antithrombin III or anti–Factor Xa deficiencies and missed enoxaparin doses. Recent data suggest that a difference in reaction time (time to initial fibrin formation) greater than 1 minute between heparinase and standard thrombelastogram (TEG) is associated with a decreased risk of VTE.

Objective  To evaluate the effectiveness of TEG-adjusted prophylactic enoxaparin dosing among trauma and surgical patients.

Design, Setting, and Participants  This randomized clinical trial, conducted from October 2012 to May 2015, compared standard dosing (30 mg twice daily) with TEG-adjusted enoxaparin dosing (35 mg twice daily) for 185 surgical and trauma patients screened for VTE at 3 level I trauma centers in the United States.

Main Outcomes and Measures  The incidence of VTE, bleeding complications, anti–Factor Xa deficiency, and antithrombin III deficiency.

Results  Of the 185 trial participants, 89 were randomized to the control group (median age, 44.0 years; 55.1% male) and 96 to the intervention group (median age, 48.5 years; 74.0% male). Patients in the intervention group received a higher median enoxaparin dose than control patients (35 mg vs 30 mg twice daily; P < .001). Anti–Factor Xa levels in intervention patients were not higher than levels in control patients until day 6 (0.4 U/mL vs 0.21 U/mL; P < .001). Only 22 patients (11.9%) achieved a difference in reaction time greater than 1 minute, which was similar between the control and intervention groups (10.4% vs 13.5%; P = .68). The time to enoxaparin initiation was similar between the control and intervention groups (median [range] days, 1.0 [0.0-2.0] vs 1.0 [1.0-2.0]; P = .39), and the number of patients who missed at least 1 dose was also similar (43 [48.3%] vs 54 [56.3%]; P = .30). Rates of VTE (6 [6.7%] vs 6 [6.3%]; P > .99) were similar, but the difference in bleeding complications (5 [5.6%] vs 13 [13.5%]; P = .08) was not statistically significant. Antithrombin III and anti–Factor Xa deficiencies and hypercoaguable TEG parameters, including elevated coagulation index (>3), maximum amplitude (>74 mm), and G value (>12.4 dynes/cm2), were prevalent in both groups. Identified risk factors for VTE included older age (61.0 years vs 46.0 years; P = .04), higher body mass index (calculated as weight in kilograms divided by height in meters squared; 30.6 vs 27.1; P = .03), increased Acute Physiology and Chronic Health Evaluation II score (8.5 vs 7.0; P = .03), and increased percentage of missed doses per patient (14.8% vs 2.5%; P = .05).

Conclusions and Relevance  The incidence of VTE was low and similar between groups; however, few patients achieved a difference in reaction time greater than 1 minute. Antithrombin III deficiencies and hypercoaguable TEG parameters were prevalent among patients with VTE. Low VTE incidence may be due to an early time to enoxaparin initiation and an overall healthier and less severely injured study population than previously reported.

Trial Registration  clinicaltrials.gov Identifier: NCT00990236.

Figures in this Article

Figures

Place holder to copy figure label and caption
Figure 1.
Study CONSORT Diagram
Graphic Jump Location
Place holder to copy figure label and caption
Figure 2.
Enoxaparin Dose Adjustment Protocol

ΔR indicates time to initial fibrin formation in minutes; TEG, thromboelastogram.

Graphic Jump Location

Tables

References

Correspondence

CME
Also Meets CME requirements for:
Browse CME for all U.S. States
Accreditation Information
The American Medical Association is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians. The AMA designates this journal-based CME activity for a maximum of 1 AMA PRA Category 1 CreditTM per course. Physicians should claim only the credit commensurate with the extent of their participation in the activity. Physicians who complete the CME course and score at least 80% correct on the quiz are eligible for AMA PRA Category 1 CreditTM.
Note: You must get at least of the answers correct to pass this quiz.
Please click the checkbox indicating that you have read the full article in order to submit your answers.
Your answers have been saved for later.
You have not filled in all the answers to complete this quiz
The following questions were not answered:
Sorry, you have unsuccessfully completed this CME quiz with a score of
The following questions were not answered correctly:
Commitment to Change (optional):
Indicate what change(s) you will implement in your practice, if any, based on this CME course.
Your quiz results:
The filled radio buttons indicate your responses. The preferred responses are highlighted
For CME Course: A Proposed Model for Initial Assessment and Management of Acute Heart Failure Syndromes
Indicate what changes(s) you will implement in your practice, if any, based on this CME course.

Multimedia

Some tools below are only available to our subscribers or users with an online account.

2,013 Views
0 Citations
×

Sign in

Purchase Options

• Buy this article
• Subscribe to the journal
• Rent this article ?

Related Content

Customize your page view by dragging & repositioning the boxes below.

See Also...
Articles Related By Topic
Related Collections
Jobs
brightcove.createExperiences();