Impact of augmented renal clearance on enoxaparin therapy in critically ill patients

Background and aim of the work
Augmented renal clearance (ARC) was reported in critically ill patients. ARC was associated with poor patient outcome due to decreased effectiveness of drugs leading to treatment failure. The aim of this study is to find the possible impact of ARC on therapeutic action of enoxaparin measured by anti-factor Xa activity.
Patients and methods
Fifty critically ill patients receiving enoxaparin prophylactic dose (40 mg/day) were included in the study. Creatinine clearance was measured and patients were divided into two groups: normal kidney function group (group C) and augmented renal clearance group (group A). serum anti-factor Xa was measured at baseline, four hours, 12 h, and 24 h. Both groups were compared regarding demographic data, severity scores, kidney function, and anti-factor Xa activity.
Results
Twenty patients (40%) showed ARC and thirty patients (60%) showed normal kidney function. Creatinine clearance was 214 ± 6 in group A versus 112 ± 11 in group C (P = 0.001). Serum anti-factor Xa levels was similar in the two groups after four hours (0.2 ± 0.07 vs. 0.2 ± 0.05, P = 1). Serum anti-Xa levels were significantly lower in group A compared to group C at 12 and 24 h (0.06 ± 0.03 vs. 0.1 ± 0.04, P = 0.004), (0.01 ± 0.01 vs. 0.05 ± 0.01, P = 0.001) respectively.
Conclusion
ARC patients showed short activity of enoxaparin. This finding draws the attention towards dose adjustment in this type of patients.