Thrombelastography Based Dosing of Enoxaparin
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|ClinicalTrials.gov Identifier: NCT00990236|
Recruitment Status : Completed
First Posted : October 6, 2009
Results First Posted : March 16, 2020
Last Update Posted : April 3, 2020
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 or disease||Intervention/treatment||Phase|
|Thromboembolic Complications||Drug: Enoxaparin dose adjusted Lovenox based on TEG Drug: Enoxaparin 30 mg BID||Not Applicable|
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.
|Study Type :||Interventional (Clinical Trial)|
|Actual Enrollment :||185 participants|
|Intervention Model:||Parallel Assignment|
|Masking:||Double (Participant, Care Provider)|
|Official Title:||Thrombelastography Based Dosing of Enoxaparin for Thromboprophylaxis: a Prospective Randomized Trial|
|Study Start Date :||September 2009|
|Actual Primary Completion Date :||March 2015|
|Actual Study Completion Date :||March 2015|
Active Comparator: Enoxaparin 30 mg BID
standard dose enoxaparin thromboprophylaxis (30 mg twice daily)
Drug: Enoxaparin 30 mg BID
Enoxaparin dose of 30 mg twice a day without any adjustments
Other Name: enoxaparin, lovenox
Experimental: Enoxaparin dose adjusted based on TEG
enoxaparin dose modified based on TEG results
Drug: Enoxaparin dose adjusted Lovenox based on TEG
Enoxaparin doses will be adjusted (10 mg BID) based on delta-R results from TEG. Delta-R < 1.0 min - increase dose by 10 mg BID; delta-R >/= 1.0 min and </= 2.0 min - no change; delta-R > 2.0 min - decrease dose by 10 mg BID.
Other Name: enoxaparin, lovenox
- Development of Deep Vein Thrombosis (DVT) [ Time Frame: Through study completion, assessed up to 120 days post randomization ]An ultrasound duplex will be completed at least one time after randomization to determine if the subject has developed a DVT.
- Incidence of Bleeding Complications [ Time Frame: Through study completion, assessed up to 120 days post randomization ]An increase in bleeding complications will be assessed daily during hospitalization
To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT00990236
|United States, Oregon|
|Oregon Health & Science University|
|Portland, Oregon, United States, 97239|
|United States, Texas|
|University of Texas Health Science Center at Houston|
|Houston, Texas, United States|
|United States, Washington|
|University of Washington|
|Seattle, Washington, United States|
|Principal Investigator:||Martin Schreiber, MD FACS||Oregon Health and Science University|