Predictors of serum vancomycin levels in peritoneal dialysis-associated peritonitis

An investigation into the correlation between intraperitoneal teicoplanin concentrations and treatment outcomes in peritoneal dialysis-associated peritonitis

Peritoneal dialysis-associated peritonitis (PDAP) is a frequent complication of peritoneal dialysis. The guidelines from the International Society for Peritoneal Dialysis (ISPD) suggest administering teicoplanin through the peritoneal route to treat PDAP, but do not specify the ideal concentration for peritoneal dialysis effluent (PDE). Patients meeting the trial criteria for PDAP in our hospital between July 2022 and December 2023 were enrolled. Data on PDE white blood cell count, PDE neutrophil percentage, clinical symptoms, CRP, and PCT were gathered pre- and post-treatment. Incidences of adverse drug reaction (ADR) and case numbers during treatment were recorded. Subsequently, patients were categorized into cured and uncured groups for evaluating the relationship between PDE teicoplanin concentration and treatment effectiveness. The self-control study results on teicoplanin efficacy indicated intraperitoneal teicoplanin administration achieved an efficacy rate of 88.9% and an ADR incidence of 5.5% in treating PDAP patients. There was no observed correlation between teicoplanin blood concentration and PDE concentration. PDE teicoplanin concentrations on days 1, 3, 5, and 7 post-dosing were higher inthe cured group, with a significant contrast in PDE concentration on day 5 between the 18.98 ± 2.43 mg/L of the cured group and the 12.07 ± 2.68 mg/L of the uncured group. ROC curve revealed a higher likelihood of cure in patients when PDE teicoplanin concentration exceeded 15.138 mg/L on day 5 post-dosing. Univariate and multifactorial studies identified 24-h urine volume and the number of daily abdominal dialysis sessions as influential factors in PDE teicoplanin concentration on day 5. A positive correlation was found between 24-h urine volume and PDE teicoplanin concentration, with PDAP patients having urine volume over 537 mL showing significantly higher drug concentrations. Conversely, the number of daily PDAP sessions was negatively correlated with PDE teicoplanin concentrations, indicating that patients with 1∼3 daily PDAP sessions had notably higher PDE teicoplanin concentrations compared to those with 4∼6 sessions. Therefore, PDAP patients who use intraperitoneal teicoplanin could effectively control infection by monitoring the PDE teicoplanin concentration (>15.138 mg/L) on day 5 after dosing.

Vancomycin Dosing Strategy for the Treatment of Peritonitis in a Child on Automated Peritoneal Dialysis: A First Pediatric Case Report

BACKGROUND

Bacterial peritonitis is a common complication of peritoneal dialysis. In the absence of systemic signs of infection, adult guidelines recommend treatment with intraperitoneal vancomycin either as empiric coverage of gram-positive organisms or as targeted therapy. However, there is no guidance on how to administer vancomycin in children on automated peritoneal dialysis.

CASE REPORT

We report vancomycin pharmacokinetics upon intraperitoneal administration for the treatment of a Staphylococcus hominis peritonitis in an 11-year-old patient on automated nocturnal intermittent peritoneal dialysis. While the patient was hospitalized, vancomycin was administered intraperitoneally as a continuous treatment. After hospital discharge, the nocturnal peritoneal dialysis was resumed. In the absence of treatment guidelines, intraperitoneal vancomycin was initially administered empirically only during the nocturnal dialysis exchanges which led to repetitive subtherapeutic vancomycin plasma concentrations and the persistence of S. hominis in dialysate cultures. Based on studies in adults, the dosing strategy was subsequently modified to administer vancomycin at a dosage of 15 mg kg-1 in the dialysate with a 6-h dwell period prior to the nocturnal dialysis thereby allowing to reach optimal peak concentrations. The dosing interval was subsequently individualized using therapeutic drug monitoring to ensure residual vancomycin concentrations > 10 mg L-1 thereby leading to clinical and microbiological recovery.

CONCLUSIONS

This case presents a dosing strategy based on a comprehensive review of the literature and highlights that a sufficient dwell period is critical when treating pediatric patients on automated peritoneal dialysis in order to allow vancomycin distribution and equilibration between the dialysate and the plasma.

Machine learning-based prediction of vancomycin concentration after abdominal administration in patients with peritoneal dialysis-related peritonitis

INTRODUCTION

Peritonitis is a serious complication of peritoneal dialysis (PD), in which insufficient control of antibacterial drug concentrations poses a significant risk for poor outcomes. Predicting antibacterial drug concentrations is crucial in clinical practice. The limitations imposed by compartment models have presented a considerable challenge.

METHODS

In this study, we employed machine learning as model-free methods to circumvent the constraints of compartment models. We collected data from 68 observations from 38 patients with peritoneal dialysis-related peritonitis who were treated with vancomycin from the EHR system. This data included information about drug administration, demographic details, and experimental indicators as predictors. We constructed models using Genetic Adaptive Supporting Vector Regression (GA-SVR), KNN-regression, GBM, XGBoost, and a stacking ensemble model. Additionally, we used RMSE loss and partial-dependence profiles to elucidate the effects of these predictors.

RESULTS

GA-SVAR outperformed other large-scale models. In 10-fold cross-validation, the RMSE ratio and R-squared values for direct concentration prediction were 23.5% and 0.633, respectively. The ROC AUC for predicting concentrations below 15 and exceeding 20 μg/mL were 0.890 and 0.948, respectively. Notably, the most influential predictors included times of drug administration and weight. These predictors were also influenced by residual kidney function.

CONCLUSION

To assist in controlling vancomycin concentrations for patients with PD-related peritonitis in clinical practice, we developed GA-SVR and a corresponding explainer model. Our study improves the controlling of vancomycin in clinical settings by enhancing our understanding of vancomycin concentration in patients with PD-related peritonitis.

The Association Between Serum Vancomycin Level and Clinical Outcome in Patients With Peritoneal Dialysis Associated Peritonitis

Introduction

Intraperitoneal (IP) vancomycin is often first-line empiric therapy and then maintenance therapy for peritoneal dialysis (PD) peritonitis. However, how vancomycin serum levels correlate with clinical outcomes remains unclear.

Methods

We conducted a retrospective single-center adult cohort study of 98 patients with PD peritonitis treated with IP vancomycin between January 2016 and May 2022. The association between nadir vancomycin level and cure was evaluated in a logistic regression model, first unadjusted and then adjusted for age, sex, weight, glomerular filtration rate (GFR), and total number of days on PD. Vancomycin was assessed both as a continuous exposure (per 1 mg/l increase) and as a categorical exposure (<15 mg/l vs. ≥15 mg/l). A receiver operating characteristic curve (ROC) was created to explore nadir vancomycin level thresholds in an attempt to identify an optimal target level during treatment.

Results

Of the patients, 81% achieved cure, and patients with nadir vancomycin level ≥15 mg/l were 7.5 times more likely to experience cure compared to those with a nadir level <15 mg/l (odds ratio [OR] 7.58, 95% confidence interval [CI] 1.71-33.57, P = 0.008). Weight, GFR, days on PD, sex, and age were not independently associated with outcome. The vancomycin level with the greatest discriminatory capacity for cure on the ROC analysis was 14.4 mg/l.

Conclusion

Increasing IP vancomycin serum levels are associated with increased odds of cure; and maintaining vancomycin serum levels above 14-15 mg/l throughout the course of PD peritonitis treatment is likely to improve clinical outcomes.