Thrombelastography Based Dosing of Enoxaparin

The recruitment status of this study is unknown because the information has not been verified recently.
Verified October 2009 by Oregon Health and Science University.
Recruitment status was  Recruiting
Sponsor:
Information provided by:
Oregon Health and Science University
ClinicalTrials.gov Identifier:
NCT00990236
First received: September 29, 2009
Last updated: October 5, 2009
Last verified: October 2009
  Purpose

The risk of developing a blood clot occurs in up to 60% of all critical care patients. Many times enoxaparin (or Lovenox®) is given to patients who are at a higher risk of developing clots in their legs or lungs. Recent data suggest that a standard dose of Lovenox may not fully prevent the development of these clots especially in critically ill or obese patients. Routine enoxaparin dosing can also result in bleeding complications. Thrombelastography (TEG®) can be used to measure how blood clots. The purposes of this study are:

  • to learn if the TEG® can better guide physicians in prescribing an effective dose of Lovenox compared to standard doses recommended by the drug company in preventing blood clots from developing in the legs and lungs, and
  • to compare the development of blood clots in patients receiving the standard dose of enoxaparin compared to patients receiving a TEG® guided dose of enoxaparin.
  • to determine if TEG guided dosing results in decreased bleeding complications compared to standard dosing.

Condition Intervention
Thromboembolic Complications
Device: Thrombelastography (TEG®)

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Safety/Efficacy Study
Intervention Model: Single Group Assignment
Masking: Double Blind (Subject, Caregiver)
Primary Purpose: Prevention
Official Title: Thrombelastography Based Dosing of Enoxaparin for Thromboprophylaxis: a Prospective Randomized Trial

Resource links provided by NLM:


Further study details as provided by Oregon Health and Science University:

Primary Outcome Measures:
  • Deep vein thrombosis (DVT) prevention [ Time Frame: At 3 months, 6 months and 1 year from date of first enrolled subject ] [ Designated as safety issue: Yes ]

Secondary Outcome Measures:
  • Incidence of thromboembolic complications [ Time Frame: Daily, while on study drug, then at 3 months, 6 months and 1 year from date of first enrolled subject ] [ Designated as safety issue: Yes ]

Estimated Enrollment: 200
Study Start Date: September 2009
Estimated Study Completion Date: October 2010
Estimated Primary Completion Date: August 2010 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
No Intervention: Group 1
standard dose enoxaparin thromboprophylaxis (30 mg twice daily)
Device: Thrombelastography (TEG®)
TEG 5000 Series Analyzer is an FDA approved device that measures blood clotting using whole blood. Blood will be collected from subjects and analyzed using the TEG. Subjects will not have direct contact with the TEG.
Experimental: Group 2
enoxaparin, modified dose based on results of the TEG test
Device: Thrombelastography (TEG®)
TEG 5000 Series Analyzer is an FDA approved device that measures blood clotting using whole blood. Blood will be collected from subjects and analyzed using the TEG. Subjects will not have direct contact with the TEG.

Detailed Description:

Hypothesis:

Enoxaparin dosed to maintain a TEG® ΔR greater than 1.0 minute will decrease the incidence of DVT compared to standard dosing.

Initiation of enoxaparin thromboprophylaxis will be done by the treatment team. Once enrolled, the subject will be randomized to continue receiving standard dose enoxaparin (30 mg twice daily) or variable TEG® guided enoxaparin dosing. The treatment team and the subject will be blinded regarding the arm in which the patient is enrolled. Patient characteristics: age, gender, body mass index (BMI), comorbidities, Acute Physiology and Chronic Health Evaluation II score (APACHE II), injuries, and operations will be collected. As part of standard protocol in the ICU, all patients will undergo weekly ultrasound duplex examination of the lower extremities for presence of deep venous thrombosis.

A baseline TEG® will be completed on each patient when they are enrolled in the study. The blood will be drawn between four and six hours after the morning dose is administered, corresponding to maximum tissue levels of enoxaparin. TEG® assays will be run in duplicate for each patient, with and without heparinase, which negates the effects of enoxaparin in the assay.

Those patients randomized to the control arm of the study will have TEG® performed at baseline and daily for one week, then twice weekly. The twice weekly TEG® assays will be done until the patient is discharged from inpatient care or enoxaparin is discontinued by the treatment team. No adjustments will be made to their enoxaparin dosing.

Patients in the TEG® guided enoxaparin dosing arm will start treatment as ordered by the primary treatment team. After the second TEG®, the dose of enoxaparin will be adjusted in 10 mg increments per dose in order to reach a target ΔR between 1.0 and 1.4 minutes. If the initial ΔR is greater than 1.4 minutes, the dose of enoxaparin will be decreased by 10 mg increments until the target ΔR is achieved. Patients will have TEGs® performed daily and adjustment of dosing until the target ΔR is reached. Once the target ΔR is achieved, TEG® will be done twice weekly until the patient is discharged from inpatient care or enoxaparin is discontinued by the treatment team. All patients will be assessed daily by study personnel for bleeding complications. If bleeding complications occur, subjects will be withdrawn from the study. If interim analysis identifies a significant difference in bleeding complications between groups the study will be terminated.

  Eligibility

Ages Eligible for Study:   15 Years and older
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  • Inpatient initiated on enoxaparin thromboprophylaxis
  • Age greater than 15 years

Exclusion Criteria:

  • Unable to obtain consent from patient or ARR
  • Presence of: intracranial hemorrhage, brain injury
  • Receiving therapeutic dose enoxaparin
  • Receiving other forms of anticoagulation
  • Receiving non-standard dosing regimen of enoxaparin
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT00990236

Contacts
Contact: Kim Simmons, RN, BSN 503 418-2101 simmonsk@ohsu.edu
Contact: Samantha Underwood, MS 503 494-8481 underwos@ohsu.edu

Locations
United States, Oregon
Oregon Health & Science University Recruiting
Portland, Oregon, United States, 97239
Contact: Kim Simmons, RN, BSN    503-418-2101    simmonsk@ohsu.edu   
Contact: Samantha Underwood, MS    503 494-8481    underwos@ohsu.edu   
Principal Investigator: Martin Schreiber, MD FACS         
Sub-Investigator: Philbert Van, MD         
Sub-Investigator: Jennifer Watters, MD         
Sub-Investigator: Susan Rowell, MD         
Sub-Investigator: Jerome Differding, MPH         
Sub-Investigator: Samantha Underwood, MS         
Sub-Investigator: Kim Simmons, RN, BSN         
Sponsors and Collaborators
Oregon Health and Science University
Investigators
Principal Investigator: Martin Schreiber, MD FACS Oregon Health and Science University
  More Information

No publications provided

Responsible Party: Martin Schreiber, MD FACS, Oregon Health & Science University
ClinicalTrials.gov Identifier: NCT00990236     History of Changes
Other Study ID Numbers: 001-01
Study First Received: September 29, 2009
Last Updated: October 5, 2009
Health Authority: United States: Institutional Review Board

Keywords provided by Oregon Health and Science University:
deep vein thrombosis
superficial venous thrombosis
pulmonary embolus

Additional relevant MeSH terms:
Enoxaparin
Anticoagulants
Hematologic Agents
Therapeutic Uses
Pharmacologic Actions
Fibrinolytic Agents
Fibrin Modulating Agents
Molecular Mechanisms of Pharmacological Action
Cardiovascular Agents

ClinicalTrials.gov processed this record on August 21, 2014