The role of monitoring vancomycin levels in patients with peritoneal dialysis-associated peritonitis.

BACKGROUND: There is limited available evidence regarding the role of monitoring serum vancomycin concentrations during treatment of peritoneal dialysis (PD)-associated peritonitis.

METHODS: A total of 150 PD patients experiencing 256 episodes of either gram-positive or culture-negative peritonitis were included to investigate the relationship between measured serum vancomycin within the first week and clinical outcomes of cure, relapse, repeat or recurrence of peritonitis, catheter removal, temporary or permanent transfer to hemodialysis, hospitalization and death.

RESULTS: Vancomycin was used as an initial empiric antibiotic in 54 gram-positive or culture-negative peritonitis episodes among 34 patients. The median number of serum vancomycin level measurements in the first week was 3 (interquartile range; IQR 1 - 4). The mean day-2 vancomycin level, measured in 34 (63%) episodes, was 17.5 ± 5.2 mg/L. Hospitalized patients were more likely to have serum vancomycin levels measured on day 2 and ≥ 3 measurements in the first week. The peritonitis cure rates were similar between patients with < 3 and ≥ 3 measurements in the first week (77% vs 57%, p = 0.12) and if day-2 vancomycin levels were measured or not (68% vs 65%, p = 0.84). The average day-2 (18.0 ± 5.9 vs 16.6 ± 3.2, p = 0.5), first-week average (18.6 ± 5.1 vs 18.6 ± 4.3, p = 0.9) and nadir (14.5 ± 4.1 vs 13.6 ± 4.2, p = 0.5) vancomycin levels were comparable in patients who did or did not achieve peritonitis cure. Similar results were observed for all other clinical outcomes.

CONCLUSION: The clinical outcomes of gram-positive and culture-negative peritonitis episodes are not associated with either the frequency or levels of serum vancomycin measurements in the first week of treatment when vancomycin is dosed according to International Society for Peritoneal Dialysis (ISPD) Guidelines.