Continuous infusion of vancomycin in septic patients receiving continuous renal replacement therapy

Vancomycin is frequently administered as a continuous infusion to treat severe infections caused by Gram-positive bacteria. Previous studies have suggested a loading dose of 15 mg/kg followed by continuous infusion of 30 mg/kg in patients with normal renal function; however, there are no dosing recommendations in patients with renal failure undergoing continuous renal replacement therapy (CRRT). Data from all adult septic patients admitted to a Department of Intensive Care over a 3-year period in whom vancomycin was given as a continuous infusion were reviewed. Patients were included if they received vancomycin for ≥48 h during CRRT. Vancomycin levels were obtained daily. During the study period, 85 patients (56 male; mean age 65 ± 15 years; weight 85 ± 24 kg) met the inclusion criteria. Median (interquartile range) APACHE II and SOFA scores were 24 (20–29) and 11 (7–14), respectively, and the overall mortality rate was 59%. Mean vancomycin doses were 16.4 ± 6.4 (loading dose), 23.5 ± 8.1 (Day 1), 23.2 ± 7.4 (Day 2) and 23.3 ± 11.0 (Day 3) mg/kg, resulting in blood concentrations of 24.7 ± 9.0 (Day 1), 26.0 ± 8.1 (Day 2) and 27.7 ± 9.3 (Day 3) μg/mL. On Day 1, 43 patients (51%) had adequate drug concentrations (20–30 μg/mL), 17 (20%) had levels >30 μg/mL and 25 (29%) had levels <20 μg/mL. Most patients with adequate drug concentrations received a daily dose of 16–35 mg/kg. The intensity of CRRT directly influenced vancomycin concentrations on Day 1 of therapy.