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Rapid Point-of-Care Assay of Enoxaparin Anticoagulant Efficacy in Whole Blood
Published on: October 12, 2012
Weight-based enoxaparin thromboprophylaxis in young trauma patients: analysis of the CLOTT-1 registry
Sarah Lombardo1, Marta McCrum1, M Margaret Knudson2
1Surgery, University of Utah, Salt Lake City, Utah, USA.
Insights
Weight-based enoxaparin prophylaxis did not reduce venous thromboembolism (VTE) risk compared to standard fixed dosing in trauma patients. Early VTE prophylaxis initiation, however, significantly lowered VTE rates.
Area of Science:
- Trauma surgery
- Pharmacology
- Critical care medicine
Background:
- Optimal enoxaparin dosing for venous thromboembolism (VTE) prophylaxis is not well-established.
- Weight-based (WB) dosing increases anti-factor Xa levels without routine monitoring, but its impact on VTE risk requires clarification.
Purpose of the Study:
- To investigate if weight-based (WB) enoxaparin dosing reduces VTE risk compared to standard fixed dosing (SFD) in trauma patients.
- To evaluate the impact of prophylaxis timing on VTE incidence.
Main Methods:
- Analysis of 4360 patients from the CLOTT-1 registry receiving prophylactic enoxaparin.
- Categorization into WB (0.45-0.55 mg/kg BID) or SFD (30 mg BID or 40 mg QD) groups.
- Multivariate logistic regression to compare VTE incidence between groups and assess timing effects.
Main Results:
- No significant difference in VTE rates between WB and SFD groups (adjusted OR 0.75; 95% CI 0.38-1.48).
- Early prophylaxis initiation was associated with a significant reduction in VTE (adjusted OR 0.47; 95% CI 0.30-0.74).
- WB patients were younger and more severely injured; obesity was more common in the SFD group.
Conclusions:
- Weight-based enoxaparin prophylaxis does not appear to reduce VTE rates compared to standard fixed dosing in young trauma patients.
- The timing of enoxaparin initiation may be a more critical factor in VTE prevention than the dosing strategy.
- Further research is needed across diverse patient populations to validate these findings.
Introduction:
Optimal venous thromboembolism (VTE) enoxaparin prophylaxis dosing remains elusive. Weight-based (WB) dosing safely increases anti-factor Xa levels without the need for routine monitoring but it is unclear if it leads to lower VTE risk. We hypothesized that WB dosing would decrease VTE risk compared with standard fixed dosing (SFD).
Methods:
Patients from the prospective, observational CLOTT-1 registry receiving prophylactic enoxaparin (n=5539) were categorized as WB (0.45-0.55 mg/kg two times per day) or SFD (30 mg two times per day, 40 mg once a day). Multivariate logistic regression was used to generate a predicted probability of VTE for WB and SFD patients.
Results:
Of 4360 patients analyzed, 1065 (24.4%) were WB and 3295 (75.6%) were SFD. WB patients were younger, female, more severely injured, and underwent major operation or major venous repair at a higher rate than individuals in the SFD group. Obesity was more common among the SFD group. Unadjusted VTE rates were comparable (WB 3.1% vs. SFD 3.9%; p=0.221). Early prophylaxis was associated with lower VTE rate (1.4% vs. 5.0%; p=0.001) and deep vein thrombosis (0.9% vs. 4.4%; p<0.001), but not pulmonary embolism (0.7% vs. 1.4%; p=0.259). After adjustment, VTE incidence did not differ by dosing strategy (adjusted OR (aOR) 0.75, 95% CI 0.38 to 1.48); however, early administration was associated with a significant reduction in VTE (aOR 0.47, 95% CI 0.30 to 0.74).
Conclusion:
In young trauma patients, WB prophylaxis is not associated with reduced VTE rate when compared with SFD. The timing of the initiation of chemoprophylaxis may be more important than the dosing strategy. Further studies need to evaluate these findings across a wider age and comorbidity spectrum.
Level Of Evidence:
Level IV, therapeutic/care management.
