Compliance With Enoxaparin Dosing and Monitoring Guidelines and the Impact on Patient Length of Stay

Katharine R. Dekker, Brooke L. Myers, Michael A. Barras

To investigate the compliance of prescribers with the state-wide Queensland Health (QH) guidelines for dosing and monitoring of enoxaparin, and to examine the effect that compliance has on the patients' length of stay (LOS) in hospital. A 4-week retrospective study of consecutive inpatients who were administered enoxaparin for the treatment of an embolic disease. Data collected included influential patient demographics such as weight, renal function; details of antifactor Xa (aXa) monitoring, and patient LOS. All dosing and monitoring for each patient was compared to the current QH guidelines for enoxaparin usage; a multidisciplinary consensus document. The reasons for noncompliance were quantified and explored. A total of 67 inpatients were recruited. The median (range) age, weight, and creatinine clearance of patients were 66 years (18-92), 78.5 kg (47.6-182), and 64 mL/min (16-180), respectively. Only 20 (30%) patients received enoxaparin in compliance with QH guidelines, leaving 47 (70%) noncompliant. The median (range) LOS was 7 (2-58) days for the compliant group versus 15 days (2-101) for the noncompliant (P = 0.06, Mann-Whitney U test). A total of 10 (15%) patients were monitored for aXa; none of whom were monitored correctly. Twenty-eight patients did not receive monitoring when indicated (moderate or severe renal impairment, weight >105 kg, or extended duration of therapy). In these patients, the median (range) LOS was 16.5 days (2-101). Current prescribing of enoxaparin does not match state guidelines. Although not significant, there was a trend toward noncompliant patients having a greater LOS in hospital. The quality of aXa monitoring is suboptimal and barriers need to be explored. Larger studies are warranted.