Thrombelastography Based Dosing of Enoxaparin
Information source: Oregon Health and Science University
ClinicalTrials.gov processed this data on August 23, 2015 Link to the current ClinicalTrials.gov record.
Condition(s) targeted: Thromboembolic Complications
Intervention: Thrombelastography (TEG®) (Device)
Phase: N/A
Status: Recruiting
Sponsored by: Oregon Health and Science University Official(s) and/or principal investigator(s): Martin Schreiber, MD FACS, Principal Investigator, Affiliation: Oregon Health and Science University
Overall contact: Kim Simmons, RN, BSN, Phone: 503 418-2101, Email: simmonsk@ohsu.edu
Summary
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.
Clinical Details
Official title: Thrombelastography Based Dosing of Enoxaparin for Thromboprophylaxis: a Prospective Randomized Trial
Study design: Allocation: Randomized, Endpoint Classification: Safety/Efficacy Study, Intervention Model: Single Group Assignment, Masking: Double Blind (Subject, Caregiver), Primary Purpose: Prevention
Primary outcome: Deep vein thrombosis (DVT) prevention
Secondary outcome: Incidence of thromboembolic complications
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
Minimum age: 15 Years.
Maximum age: N/A.
Gender(s): Both.
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
Locations and Contacts
Kim Simmons, RN, BSN, Phone: 503 418-2101, Email: simmonsk@ohsu.edu
Oregon Health & Science University, Portland, Oregon 97239, United States; Recruiting Kim Simmons, RN, BSN, Phone: 503-418-2101, Email: simmonsk@ohsu.edu Samantha Underwood, MS, Phone: 503 494-8481, Email: underwos@ohsu.edu Martin Schreiber, MD FACS, Principal 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, Sub-Investigator
Additional Information
Starting date: September 2009
Last updated: October 5, 2009
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