Vancomycin pharmacokinetics during high-volume continuous venovenous hemofiltration in critically ill septic patients.

Aims: To assess the influence of continuous venovenous hemofiltration (CVVH) at a filtration rate of 45 mL/kg/h on vancomycin pharmacokinetics in critically ill septic patients with acute kidney injury (AKI).

Methods: Seventeen adult septic patients with acute kidney injury treated with CVVH and vancomycin were included. All patients received first dose of 1.0 g intravenously followed by 1.0 g/12 h if not adjusted. In sixteen patients vancomycin was introduced on the day of the start of CRRT therapy. Blood samples and ultrafiltrates were obtained before and 0.5, 1, 6 and 12 h after vancomycin administration.

Results: On the first day, the median total vancomycin clearance (Cltot) was 0.89 mL/min/kg (range 0.31 - 2.16). CRRT clearance accounted for around 50-60% of the total clearance of vancomycin found in a population with normal renal function (0.97 mL/min/kg). Vancomycin serum concentrations after the first dose were below the required target of 10 mg/L as early as 6 h in 10 patients, AUC0-24/MIC ≥ 400 ratio was achieved in 10 patients on the first day.

Conclusions: CVVH at a filtration rate of 45 mL/kg/h leads to high and rapid extracorporeal removal of vancomycin in critically ill patients. Due to the rapid change in patient clinical status it was impossible to predict a fixed dosage regimen. We recommend blood sampling as early as 6 h after first vancomycin dose with maintenance dose based on vancomycin serum level monitoring.