Serum vancomycin levels predict the short-term adverse outcomes of peritoneal dialysis-associated peritonitis

The role of monitoring serum vancomycin levels during treatment of peritoneal dialysis (PD)-associated peritonitis is controversial. Substantial inter-individual variability may result in suboptimal serum levels despite similar dosing of vancomycin. The published predictors of suboptimal serum vancomycin levels remain limited.

Data were retrospectively collected from 541 patients on continuous ambulatory peritoneal dialysis between 1 January 2018 and 31 December 312019. For gram-positive cocci and culture-negative peritonitis, we adopted a vancomycin administration and monitoring protocol. Short-term adverse outcomes of PD-associated peritonitis, including transfer to haemodialysis, death, persistent infection beyond planned therapy duration and relapse, were observed. The association between trough serum vancomycin levels and short-term adverse outcomes was evaluated.

Intraperitoneal vancomycin was used in 61 gram-positive cocci or culture-negative peritonitis episodes in 56 patients. Fourteen episodes of short-term adverse outcomes occurred in 12 patients, whose average trough serum vancomycin levels on day 5 of treatment were significantly lower than those who didn't experience any adverse outcomes (8.4 ± 1.7 vs 12.5 ± 4.3 mg/L, p = 0.003). In gram-positive cocci or culture-negative peritonitis patients, those with higher day 5 trough serum vancomycin levels had a lower risk of short-term adverse outcomes (odds ratio: 0.6, 95% confidence interval: 0.4 to 0.9, p = 0.011). Receiver operating charecteristic curve (ROC) analyses showed that the day 5 trough serum vancomycin levels diagnostic threshold value for short-term adverse outcomes was 10.1 mg/L. After adjustments for gender, exchange volume and residual kidney function (RKF), baseline higher peritoneal transport was associated with a suboptimal (<10.1 mg/L) day 5 serum vancomycin level.

Serum vancomycin levels are correlated with short-term adverse outcomes of PD-associated peritonitis, and higher peritoneal solute transport status is associated with suboptimal trough serum vancomycin levels on day 5.