Evaluation of Vancomycin Dosing Practices in Critically Ill Patients Receiving Accelerated Venovenous Hemofiltration

Accelerated venovenous hemofiltration (AVVH) is a hybrid renal replacement therapy (RRT) offering higher hemofiltration rates and improved hemodynamic stability, but can alter pharmacokinetics and pharmacodynamics of numerous antibiotics, creating uncertainty in efficacy and toxicity. The purpose of this study was to describe vancomycin dosing practices in patients receiving AVVH, with the potential to model vancomycin dosing and monitoring strategies. This was a single-center retrospective analysis of vancomycin dosing strategies utilized in critically ill adult patients receiving AVVH. Patients were included if they received vancomycin while undergoing AVVH and had a vancomycin concentration measured within the first 24 h of initiating concomitant vancomycin and AVVH. Major endpoint of this study was the incidence of in-range vancomycin concentrations (10-20 mcg/mL) in patients undergoing AVVH. There were 52 patients included in the analysis, with 79 unique AVVH sessions with an associated vancomycin concentration assessed. Median dose of vancomycin was 1250 mg (1000-1500), or 14.5 mg/kg (12.7-16.6), per AVVH session. Incidence of in-range vancomycin concentrations was 68.4%, with a median vancomycin concentration of 17.1 mcg/mL (14.0-21.5). Median duration of vancomycin therapy with concomitant AVVH was 2 days (1-7) and the median time from AVVH completion to vancomycin concentration obtainment was 2.8 h (0.3-5.7). The majority of vancomycin concentrations collected were in range, using a median vancomycin dose of 14.5 mg/kg and achieving a median vancomycin concentration of 17.6 mcg/mL. This suggests most patients achieved in-range concentrations, but additional prospective pharmacokinetic studies are needed to understand vancomycin exposure and dosing requirements in patients undergoing AVVH.