Nomogram to Estimate the Risk of Chronic Kidney Disease-associated Pruritus in Patients with End-Stage Renal Disease Undergoing Peritoneal Dialysis: Model Development and Validation Study.

INTRODUCTION: Chronic kidney disease associated pruritus (CKD-aP) frequently occurs in patients with end-stage renal disease (ESRD) undergoing peritoneal dialysis (PD) and presents a therapeutic challenge to physicians owing to the diversity of its pathogenesis. Herein, we developed and validated a nomogram model for individualized risk estimation of CKD-aP and investigate the possible causes of CKD-aP in PD patients. METHODS: We retrospectively screened patients with CKD-aP who underwent PD between 2021 and 2023 at the First Affiliated Hospital of Xi'an Jiaotong University Peritoneal Dialysis Center. Nomograms for each outcome were computed from multivariate logistic regression models with the least absolute shrinkage and selection operator regression and univariate logistic regression for variable selection. The discriminative ability was estimated by Harrell's C-index, and the accuracy was assessed graphically with a calibration curve plot. Models were validated internally using bootstrapping and externally by calculating their performance on a validation cohort. Decision curve analysis was used to assess the model's clinical usefulness. RESULTS: In all, a total of 487 patients were entered in the analysis, including 325 in the development cohort and 162 in the validation cohort. The final nomogram incorporated four variables: age, interleukin-6, hemoglobin, residual urine volume, and renal Kt/V. The C-index of the model was 0.733 (95% CI 0.679-0.787), and the calibration curve was a straight line with a slope close to 1. Both internal and external validations confirmed the model's good performance, with C-index of 0.725 (95% CI 0.662-0.774) and 0.706 (95% CI 0.623-0.789), respectively. Decision curve analysis showed that the nomogram had good clinical benefits. CONCLUSION: Our study proposes a nomogram model for CKD-aP risk assessment in ESRD patients with PD. This nomogram might help in clinical decision-making and evidence-based selection of therapy.

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

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Influence of dietary protein on serum phosphorous levels in peritoneal dialysis patients with different initial transport function.

INTRODUCTION: This cross-sectional study investigated the influence of dietary protein intake (DPI) on serum phosphate levels in peritoneal dialysis (PD) patients and determined the DPI cutoff required to prevent hyperphosphatemia. METHODS: A total of 504 PD patients were categorized into fast (4 h dialysate/plasma [D/P] creatinine clearance ≥0.65) or slow (<0.65) peritoneal transporters. Serum phosphorus and peritoneal solute clearance were compared between the groups with different DPI. RESULTS: The fast peritoneal transporters (n = 233) were older, had lower serum albumin and phosphorus levels, and had higher peritoneal phosphorus clearance (all p < 0.001). Among the slow transporters (n = 271), serum phosphorus levels were significantly higher among patients with DPI > 1.0 g/kg/d (p < 0.001). High DPI only increased the hyperphosphatemia risk in slow transporters (not in high transporters). DPI ≥1.026 g increased the hyperphosphatemia risk in those patients (area under the curve: 0.66, p = 0.001). CONCLUSION: High DPI increases the hyperphosphatemia risk in PD patients with slower peritoneal transport function.