Pharmacokinetics and dosing of vancomycin in patients undergoing sustained low efficiency daily diafiltration (SLEDD-f): A prospective study.

BACKGROUND/PURPOSE: The pharmacokinetics of vancomycin in patients who undergo sustained low efficiency daily diafiltration (SLEDD-f) is not clear. This study aimed to determine the appropriate vancomycin dosage regimen for patients receiving SLEDD-f.

METHODS: This prospectively observational study enrolled critically ill patients older than 18 years old that used SLEDD-f as renal replacement therapy and received vancomycin treatment. An 8-h SLEDD-f was performed with FX-60 (high-flux helixone membrane, 1.4 m2 ). Serial blood samples were collected before, during, and after SLEDD-f to analyse vancomycin serum concentrations. Effluent fluid samples (a mixture of dialysate and ultrafiltrate) were also collected to determine the amount of vancomycin removal.

RESULTS: Seventeen patients were enrolled, and 10 completed the study. The amount of vancomycin removal was 447.4 ± 88.8 mg (about 78.4 ± 18.4% of the dose administered before SLEDD-f). The vancomycin concentration was reduced by 57.5 ± 14.9% during SLEDD-f, and this reduction was followed by a rebound with duration of one to three hours. The elimination half-life of vancomycin decreased from 64.1 ± 35.7 h before SLEDD-f to 7.0 ± 3.0 h during SLEDD-f.

CONCLUSION: Significant amount of vancomycin removed during SLEDD-f. Despite the existence of post-dialysis rebound, a sufficient supplemental dose is necessary to maintain therapeutic range.