Enoxaparin for VTE thromboprophylaxis during inpatient rehabilitation care: assessment of the standard fixed dosing regimen

Abstract

We aimed to examine the efficiency of fixed daily dose enoxaparin (40 mg) thromboprophylaxis strategy for patients undergoing inpatient rehabilitation. This was an observational, prospective, cohort study that included 63 hospitalized patients undergoing rehabilitative treatment following sub-acute ischemic stroke (SAIS) or spinal cord injury (SCI), with an indication for thromboprophylaxis. Anti-Xa level measured three hours post-drug administration (following three consecutive days of enoxaparin treatment or more) was utilised to assess in vivo enoxaparin activity. An anti-Xa level between 0.2-0.5 U/ml was considered evidence of effective antithrombotic activity. We found sub-prophylactic levels of anti-Xa (<0.2 U/ml) in 19% (12/63). Results were within the recommended prophylactic range (0.2-0.5 U/ml) in 73% (46/63) and were supra-prophylactic (>0.5 U/ml) in 7.9% (5/63) of patients. Anti-Xa levels were found to inversely correlate with patients’ weight and renal function as defined by creatinine clearance (CrCl) (p<0.05). Our study confirmed that a one-size-fits-all approach for venous thromboembolism (VTE) prophylaxis may be inadequate for rehabilitation patient populations. The efficacy of fixed-dose enoxaparin prophylaxis is limited and may be influenced by renal function and weight. This study suggests that anti-Xa studies and prophylactic enoxaparin dose adjustments should be considered in certain patients, such as those who are underweight, overweight and or have suboptimal renal function. No. NCT103593291, registered August 2018. • Clinicians should be aware that fixed dose enoxaparin prophylaxis will only provide adequate therapeutic response for a proportion of rehabilitation patients. • The efficacy of fixed-dose enoxaparin prophylaxis is limited and may be influenced by renal function and weight. • A personalized approach to VTE prophylaxis that includes anit-Xa studies and prophylactic dose adjustments should be considered in certain patients, such as those who are underweight, overweight and or have suboptimal renal function. • More studies are required to investigate the interaction of weight and creatinine in order to establish VTE prophylactic dosing guidelines for specific rehabilitation populations.