The Association of Cognitive Impairment with Peritoneal Dialysis-Related Peritonitis

Cognitive Dysfunction Screening in Peritoneal Dialysis Patients: A Cross-Sectional Study

Background

Mild cognitive impairment (MCI) in peritoneal dialysis (PD) patients has been described as a risk factor for worse outcomes such as peritonitis, technique failure, and mortality. In this study, we aimed to determine the prevalence of MCI in a population of PD patients and identify the possible risk factors associated with MCI.

Materials and Methods

We performed an observational, cross-sectional study to evaluate cognitive function using the Montreal Cognitive Assessment (MOCA) test and the Mini Mental State Examination (MMSE) test in PD patients. Patients with diagnosis of dementia or severe neurologic impairment, active cancer, or infection were excluded.

Results

We evaluated 66 patients (mean age 60 years); 53% were male. Prevalence of MCI assessed by MOCA test and MMSE test was 65% and 33%, respectively. Predictors of MCI with MOCA test were higher age (P = 0.0001), lower education level (P = 0.005), need of a helper (P = 0.009), and continuous ambulatory PD modality (P = 0.019). Higher Charlson comorbidity index (P = 0.002), coronary artery disease (P = 0.006), and peripheral artery disease (P = 0.033) were also associated with MCI. Lower Kt/V (P = 0.012) and lower levels of normalized protein catabolic rate (nPCR; P < 0.000) were related to MCI. MCI patients had more episodes of peritonitis (P = 0.047). Multivariable analysis showed that lower education, Kt/V, and nPCR were the most relevant factors connected to MCI (P = 0.029, P = 0.037, and P = 0.019, respectively).

Conclusion

In our PD population, MCI was detected in more than half of the patients. Patients with MCI were older, had lower education level, more disease burden, and higher risk for developing peritonitis. Lower Kt/V and nPCR levels were associated with MCI.

Peritoneal Dialysis-Related Infections

Peritoneal dialysis (PD) represents an important treatment choice for patients with kidney failure. It allows them to dialyze outside the hospital setting, facilitating enhanced opportunities to participate in life-related activities, flexibility in schedules, time and cost savings from reduced travel to dialysis centers, and improved quality of life. Despite its numerous advantages, PD utilization has been static or diminishing in parts of the world. PD-related infection, such as peritonitis, exit-site infection, or tunnel infection, is a major concern for patients, caregivers, and health professionals-which may result in hesitation to consider this as treatment or to cease therapy when these complications take place. In this review, the definition, epidemiology, risk factors, prevention, and treatment of PD-related infection on the basis of the contemporary evidence will be described.

Risk factors for cognitive impairment in patients with chronic kidney disease

BACKGROUND

Chronic kidney disease (CKD) patients have been found to be at risk of concurrent cognitive dysfunction in previous studies, which has now become an important public health issue of widespread concern.

AIM

To investigate the risk factors for concurrent cognitive dysfunction in patients with CKD.

METHODS

This is a prospective cohort study conducted among patients with CKD between October 2021 and March 2023. A questionnaire was formulated by literature review and expert consultation and included questions about age, sex, education level, per capita monthly household income, marital status, living condition, payment method, and hypertension.

RESULTS

Logistic regression analysis showed that patients aged 60-79 years [odds ratio (OR) = 1.561, P = 0.015] and ≥ 80 years (OR = 1.760, P = 0.013), participants with middle to high school education (OR = 0.820, P = 0.027), divorced or widowed individuals (OR = 1.37, P = 0.032), self-funded patients (OR = 2.368, P = 0.008), and patients with hypertension (OR = 2.011, P = 0.041) had a higher risk of cognitive impairment. The risk of cognitive impairment was lower for those with a college degree (OR = 0.435, P = 0.034) and married individuals.

CONCLUSION

The risk factors affecting cognitive dysfunction are age, 60-79 years and ≥ 80 years; education, primary school education or less; marital status, divorced or widowed; payment method, self-funded; hypertension; and CKD.

Evolution of Peritoneal Dialysis-Associated Peritonitis: Pathogen, Antibiotic Resistance, and the Impact of Lymphocyte Count on Treatment Outcomes

Purpose

Antibiotic administration leads to alterations in pathogenic organisms and antibiotic resistance, posing a significant risk to peritoneal dialysis patients' health. This study aimed to investigate changes in the cause-specific peritonitis, pathogen profiles, antibiotic resistance, and the prognostic factors among patients with peritoneal dialysis-associated peritonitis (PDAP) at our center.

Patients and Methods

We included 463 PDAP patients who attended Peking University Shenzhen Hospital between 2002 and 2023. We analyzed the effects of empirical treatment regimens with cefazolin and ceftazidime or gentamicin.

Results

From 2002 to 2023, we observed that gram-positive staphylococci emerged as the primary causative agents, while the proportion of gram-negative bacillary, enteric peritonitis, and catheter-associated peritonitis decreased significantly. However, the overall cure rate for PDAP and gram-negative bacillary peritonitis declined significantly from 2014 to 2023. Notably, we observed no increase in antibiotic resistance associated with antibiotic drugs use. In addition, reduced lymphocyte counts due to the prevalence of 2019 coronavirus disease (COVID-19) emerged as an independent risk factor for treatment failure in cases of gram-negative bacillary peritonitis.

Conclusion

We did not observe elevated antibiotic resistance in our center when employing empirical dosing strategies involving cefazolin, ceftazidime, or gentamicin. Additionally, we found that a decrease in lymphocyte count due to the COVID-19 epidemic was a significant risk factor for treatment failure in cases of gram-negative bacillary peritonitis at our center. This study provides a foundation for developing clinical treatment strategies for PDAP.

Correlation between gut microbiome and cognitive impairment in patients undergoing peritoneal dialysis

BACKGROUND

Growing evidence has demonstrated that patients undergoing peritoneal dialysis (PD) are more likely to experience cognitive impairment than patients with non-dialysis end-stage renal disease (ESRD); however, the underlying mechanisms remain unclear. This study aimed to identify the role and predictive significance of gut microbiome alterations in PD-associated cognitive impairment.

METHODS

A total of 29 non-dialysis ESRD patients and 28 PD patients were enrolled in this study and divided into subgroups according to the Montreal Cognitive Assessment (MoCA). Faecal samples were analyzed using 16 S rRNA. Mini-Mental State Examination (MMSE) and MoCA scores were used to assess the degree of cognitive impairment in patients.

RESULTS

The 16 S rRNA analysis demonstrated differences in gut microbiome abundance and structure between PD and non-dialysis ESRD patients and between PD patients with cognitive impairment (PCI) and PD patients with normal cognition (PNCI). At family and genus levels, Prevotellaceae exhibited the greatest structure difference, while Lactobacillus exhibited the greatest abundance difference between PCI and PNCI. Altered microbiota abundance significantly correlated with cognitive function and serum indicators in PD. In addition, different modules related to fatty acid, lipid, pantothenate, and coenzyme A biosynthesis, and tyrosine and tryptophan metabolism were inferred from 16 S rRNA data between PCI and PNCI. Both groups could be distinguished using models based on the abundance of Lactobacillaceae (Area under curve [AUC] = 0.83), Actinomycetaceae (AUC = 0.798), and Prevotellaceae (AUC = 0.778) families and Lactobacillus (AUC = 0.848) and Actinomyces (AUC = 0.798) genera.

CONCLUSION

Gut microbiome evaluation could aid early cognitive impairment diagnosis in patients undergoing PD.

Association of Different Total Bilirubin Levels with Prognosis of Peritoneal Dialysis-Associated Peritonitis

Background and Objectives: Peritoneal dialysis-associated peritonitis (PDAP) poses significant challenges in peritoneal dialysis (PD) patient management and outcomes. Total bilirubin has gained attention due to its antioxidant and immunomodulatory properties. However, its relationship with PDAP prognosis remains underexplored. Materials and Methods: We conducted a retrospective single-center study involving 243 PDAP patients stratified into tertile-based groups according to total bilirubin levels. The association between total bilirubin levels and treatment failure risk was investigated through statistical analyses and restricted cubic spline curve analysis. Results: Our analysis revealed a non-linear correlation between total bilirubin levels and PDAP treatment failure risk. At total bilirubin levels below 8.24 µmol/L, a protective effect was observed, while levels exceeding this threshold heightened the risk of treatment failure. Conclusions: This study unveils a dual role of total bilirubin in PDAP prognosis. Below a certain threshold, it confers protection, while higher levels exacerbate the risk of treatment failure. These findings emphasize the need for further investigation in larger, multicenter prospective studies to validate and elucidate the mechanisms behind bilirubin's impact on PDAP, potentially guiding the development of targeted therapeutic strategies.

Retinopathy is associated with impaired cognition in patients undergoing peritoneal dialysis

Objective: Previous studies have shown a relationship between retinopathy and cognition including population with and without chronic kidney disease (CKD) but data regarding peritoneal dialysis (PD) are limited. This study aims to investigate the relationship between retinopathy and cognitive impairment in patients undergoing peritoneal dialysis (PD). Methods: In this observational study, we recruited a total of 107 participants undergoing PD, consisting of 48 men and 59 women, ages ranging from 21 to 78 years. The study followed a cross-sectional design. Retinal microvascular characteristics, such as geometric changes in retinal vascular including tortuosity, fractal dimension (FD), and calibers, were assessed. Retinopathy (such as retinal hemorrhage or microaneurysms) was evaluated using digitized photographs. The Modified Mini-Mental State Examination (3MS) was performed to assess global cognitive function. Results: The prevalence rates of retinal hemorrhage, microaneurysms, and retinopathy were 25%, 30%, and 43%, respectively. The mean arteriolar and venular calibers were 63.2 and 78.5 µm, respectively, and the corresponding mean tortuosity was 37.7 ± 3.6 and 37.2 ± 3.0 mm-1. The mean FD was 1.49. After adjusting for age, sex, education, mean arterial pressure, and Charlson index, a negative association was revealed between retinopathy and 3MS scores (regression coefficient: -3.71, 95% confidence interval: -7.09 to -0.33, p = 0.03). Conclusions: Retinopathy, a condition common in patients undergoing PD, was associated with global cognitive impairment. These findings highlight retinopathy, can serve as a valuable primary screening tool for assessing the risk of cognitive decline.

Self-care or assisted PD: development of a new approach to evaluate manual peritoneal dialysis practice ability

Background

Peritoneal dialysis (PD) is a home-based therapy which requires the patients or their caregivers to perform the practice. We aimed to develop a practical approach to evaluate PD practice ability of the patients and to identify berries to self-care PD.

Methods

A structural form was designed comprising measures of physical, cognitive, and operational abilities which were required to perform manual PD independently. The evaluation was jointly conducted by a PD nurse, a nephrologist and a close family member of the patient. Patients who met all the requirements were deemed as capable of performing PD independently (self-care PD) and others were deemed as needing an assistant (assisted PD).

Results

The evaluation form was applied in 280 prevalent PD patients and 33.9% of them were assessed as needing assisted PD, mainly due to physical (62.1%) or operational (66.3%) disabilities. The evaluation result was consistent with current dialysis status in 79.3% patients and it matched better in patients who performed PD with the help of an assistant (93.0 vs. 76.8%, p = 0.014). Patients who were evaluated as having barriers to self-care PD but still performed PD without an assistant were older and demonstrated higher prevalence of diabetic nephropathy and PD-related infection, lower education level, and lower serum albumin (p < 0.05).

Conclusions

The PD practice ability assessment form is useful to identify patients with barriers to self-care PD. It provides objective information to the patients and their family to choose feasible PD practice modality, self-care, or assisted PD.

Effects of cognitive impairment and assisted peritoneal dialysis on exit-site infection in older patients

BACKGROUND

Elderly peritoneal dialysis (PD) patients required assistance for a variety of PD-related tasks. The usefulness of assisted PD in reducing the peritonitis risk has been reported; however, there is little evidence on the effectiveness of assisted PD in preventing exit-site infections in older patients.

METHODS

This was a single-center, prospective cohort study. Thirty-three patients (mean age: 74.8 ± 5.9 years) on PD were evaluated for cognitive impairment (CI) using the Japanese version of the Montreal Cognitive Assessment. They were also evaluated to determine whether they performed the exit-site care procedure alone or with assistance. Patients were categorized into four groups based on the presence or absence of CI and the presence or absence of exit-site care assistance. They were followed up until the occurrence of peritonitis and exit-site infection at the end of the follow-up.

RESULTS

Altogether, 8, 8, and 17 patients were assigned to the "without CI and without assistance", "without CI and with assistance", and "with CI and with assistance groups", respectively; no patients were assigned to the "with CI and without assistance group". Six and 16 patients experienced peritonitis and exit-site infection during follow-up, respectively. Kaplan-Meier analysis and log-rank tests revealed that the "without CI and without assistance group" was significantly associated with exit-site infection (log-rank < 0.05).

CONCLUSION

Patients who did not receive assistance for exit-site care were at a higher risk of exit-site infections, even in the absence of CI. Caregiver assistance is important for preventing exit-site infections in older patients on PD.

Are sex differences in the outcome of peritoneal dialysis explained by nurse-assistance? A cohort study with data from the RDPLF

BACKGROUND

We aimed to evaluate sex differences in peritoneal dialysis (PD) outcomes and to explore direct and indirect effects of nurse-assisted PD on outcomes.

METHODS

This was a retrospective study using data from the French Language Peritoneal Dialysis Registry of incident PD patients between 2005 and 2016. Cox proportional hazard modelling was used to analyse transfer to haemodialysis (HD), death, PD failure, peritonitis and renal transplantation. Mediation analyses with a counterfactual approach were carried out to evaluate natural direct and indirect effects of sex on transfer to HD and peritonitis, with nurse-assisted PD as a mediator a priori.

RESULTS

Of the 14659 patients included, they were 5970 females (41%) and 8689 males (59%). Women were more frequently treated by nurse-assisted PD than men ((2926/5970 (49.1%) vs. 3357/8689 (38.7%)). In the multivariable analysis, women had a lower risk of transfer to HD (cause-specific hazard ratio(cs-HR): 0.82[95% confidence interval(CI): 0.77-0.88]), death (cs-HR: 0.90[95%CI: 0.85-0.95]), peritonitis (cs-HR: 0.82[95%CI: 0.78-0.87]), PD failure (cs-HR: 0.86[95%CI: 0.83-0.90]) and a lower chance of undergoing transplant (cs-HR: 0.83[95%CI: 0.77-0.90]) than men. There was a direct effect of sex on the risk of transfer to HD (cs-HR: 0.82[95%CI: 0.82-0.83]) with an indirect effect of nurse-assisted PD (cs-HR: 0.97[95%CI: 0.96-0.99]). Nurse-assisted PD had no indirect effect on the risk of peritonitis.

CONCLUSIONS

Our results suggest that compared with men, women have both a lower risk of transfer to HD and peritonitis. Mediation analysis showed that nurse assistance was a potential mediator in the causal pathway between sex and transfer to HD.

Evaluation of modifiable risk factors for peritoneal dialysis-related peritonitis: a single-center retrospective cohort study

Background

Peritoneal dialysis (PD)-related peritonitis risk factors can be categorized as modifiable and uncorrectable. We aimed to identify modifiable risk factors for PD-related peritonitis in our facility to prevent PD-related peritonitis and continue quality improvement.

Methods

This retrospective, observational study included 90 patients who started receiving PD after 2008 and who were continued for over 1 year. Twenty-three patients experienced 40 episodes of peritonitis. Several clinical factors identified at peritonitis onset among patients with a peritonitis history were compared with those identified 1 year after PD initiation among patients without a peritonitis history, and a multivariate analysis was performed. Several serum parameter levels were evaluated as time-average concentrations (TACs; from PD initiation to 1 month before peritonitis onset or to 1 year later). The clinical factors to be investigated were selected based on previous studies.

Results

There were no significant between-group differences in baseline characteristics regarding uncorrectable factors and TAC values for serum parameters. Use of exchange devices was significantly higher (95.7% vs 71.6%; p = 0.054) whereas administration of renin-angiotensin-aldosterone system (RAS) blockers, calcium channel blockers (CCBs), or oral vitamin D was significantly lower (35.0% vs 65.7%, p = 0.002; 55.0% vs 74.6%, p = 0.036; and 55.0% vs 74.6%, p = 0.036, respectively) in the patients with history of peritonitis, although we did not find a factor independently associated with peritonitis in multivariable logistic regression.

Conclusions

Although hypokalemia, hypoalbuminemia, and exchange device use which are considered as risk factors did not affect peritonitis, administration of RAS blockers, CCBs, and oral vitamin D is significantly larger in patients without peritonitis.

Impact of assistance on peritonitis due to breach in aseptic procedure in diabetic patients: A cohort study with the RDPLF data

BACKGROUND

Diabetic patients often have physical impairment that could lead to manipulation errors in peritoneal dialysis (PD) and touch contamination. Nurse assistance in diabetic PD patients is known to help prevent peritonitis. We made the hypothesis that this lower risk of peritonitis was observed thanks to prevention of breach in aseptic procedure. We evaluated the impact of nurse-assisted PD on specific causes of peritonitis, especially on peritonitis due to a breach in aseptic procedure.

METHODS

This was a retrospective observational study of the data from the French Language Peritoneal Dialysis Registry. All diabetic patients older than age 18 years starting PD in France between 1 January 2012 and 31 December 2015 were included in the study. The event of interest was the first peritonitis event due to a breach in aseptic procedure. Death, kidney transplantation and peritonitis due to another mechanism were considered as competing events. We examined the association of the covariates with all the possible outcomes using a subdistribution hazard model developed for survival analysis in the presence of competing risks.

RESULTS

Four thousand one hundred one diabetic patients incident in PD were included in the study. At least one peritonitis event occurred in 1611 patients over the study period. A breach in aseptic procedure was reported in 441/1611 cases (27.3%): 209/575 (36.3%) in the self-care PD group, 56/217 (25.8%) in the family-assisted PD group and 176/819 (21.5%) in the nurse-assisted PD group. Both nurse and family assistance were associated with a lower risk of peritonitis due to breach in aseptic procedure in bivariate analysis. After adjustment on age, modified Charlson index, sex and diabetic nephropathy, patients treated by nurse-assisted PD (subdistribution hazard ratio (sd-HR) 0.52, 95% confidence interval (CI) 0.40-0.67) and those treated by family-assisted PD (sd-HR 0.70, 95% CI 0.51-0.95) had a lower likelihood of peritonitis due to a connection error compared to self-care PD in multivariate analysis. The modality of assistance was not associated with other causes of peritonitis in the multivariate analysis.

CONCLUSION

While both nurse-assisted PD and family-assisted PD were associated with lower risk of peritonitis due to a breach in aseptic procedure compared to self-care PD in our study, the protective effect was greater with nurse assistance.