Peritoneal dialysis in patients with failed kidney transplant: Single centre experience.

AIM: To determine if patients with failing kidney transplants who opt to have peritoneal dialysis (PD) have poor short-term PD technique survival and increased rates of peritonitis. METHODS: We performed a retrospective analysis comparing 50 consecutive patients starting PD after a failed kidney transplant to 93 incident patients starting PD (matching for age, gender, diabetes causing renal failure, ethnicity and year of starting PD). RESULTS: The mean follow-up period was 26 months. PD technique survival was lower for the post-transplant cohort. However, this did not appear to be related to PD peritonitis risk; infection rate was lower in the post-transplant group albeit not statistically significant (1 in 23.6 patient months vs 1 in 22.5 patient months). There were no differences in the proportion of Gram positive: Gran negative: Culture Negative infections. The only fungal peritonitis occurred in a Control patient. Results of baseline Peritoneal Equilibration Tests were not different; D/Pcr was 0.69 for post-TP versus 0.64 for Control (P = ns), and net UF was 250 mL for post-TP versus 310 mL for Control (P = ns). PET results after 12 months were also similar. CONCLUSION: Our study found a small but significantly higher rate of PD technique failure in the post-transplant cohort, but this did not appear to be related to peritonitis rates or peritoneal membrane function. Further studies are required to explore reasons for PD technique failure in patients who have had kidney transplant, but our study supports the use of PD in selected patient from this cohort.

Comparison of Change in Peritoneal Function in Patients on Continuous Ambulatory PD vs Automated PD.

BACKGROUND: Patients on automated peritoneal dialysis (APD) may have greater exposure to glucose in the PD fluid than those on continuous ambulatory PD (CAPD). If this causes long-term damage to the peritoneal membrane, it will have implications for a patient's choice of modality. METHODS: Membrane function of long-term APD or CAPD patients was followed prospectively. The data were collected from electronic patient records in our unit from 2000 to 2014. The rate of change in membrane transport status (D/Pcr) and ultrafiltration (UF4) for each patient was calculated using the least square regression line equation. RESULTS: We identified 106 APD and 123 CAPD patients who had a mean of 8.4 peritoneal equilibration test (PET) over 5.6 years. No differences were found in the rate of changes in D/Pcr or UF4. Baseline solute clearance (Kt/V) was lower in APD patients (1.66 vs 1.76, p = 0.04). However, APD patients experienced incremental changes to dialysis prescription that resulted in a greater increase in Kt/V compared with CAPD patients. CONCLUSION: This is the largest study comparing the long-term effect of APD vs CAPD prescriptions. Despite more glucose being prescribed, there were no differences in the evolution of peritoneal membrane transport characteristics. The lower baseline Kt/V of APD patients might be explained by our aggressive use of incremental APD (tidal with dry day). Despite greater glucose prescriptions, initiating patients on APD based on patient preference appears to be safe for the long-term integrity of the peritoneal membrane.

Hydration status measured by BCM: A potential modifiable risk factor for peritonitis in patients on peritoneal dialysis.

AIM: Peritoneal dialysis peritonitis and fluid overhydration (OH) are frequent problems in peritoneal dialysis. The latter can cause gut wall oedema or be associated with malnutrition. Both may lead to increased peritonitis risk. We wished to determine if OH is an independent risk factor for peritonitis (caused by enteric organisms). METHODS: Retrospectively study of patients with >2 bioimpedance assessments (Body Composition Monitor). We compared peritonitis rates of patients with above or below the median time-averaged hydration parameter (OH/extracellular water, OH/ECW). Multivariate analysis was performed to determine independent risk factors for peritonitis by enteric organism. RESULTS: We studied 580 patients. Peritonitis was experienced by 28% patients (followed up for an average of 17 months). The overall peritonitis rate was 1:34 patient months. Patients with low OH/ECW values had significantly lower rates of peritonitis from enteric organisms than overhydrated patients (incident rate ratio 1.53, 95% confidence interval 1.38-1.70, P < 0.001). Hydration remained an independent predictor of peritonitis from enteric organisms when multivariate model included demographic parameters (odds ratio for a 1% increment of OH/ECW was 1.05; 95% confidence interval 1.01-1.10, P < 0.02). However, including biochemical parameters of malnutrition reduced the predictive power of overhydration. CONCLUSION: We found an association between overhydration and increased rates of peritonitis. While this may partly be due to the high co-morbidity of patients (advanced age and diabetes), on multivariate analysis, only inclusion of nutritional parameters reduced this association. It remains to be determined if overhydration will prove to be a modifiable risk factor for peritonitis or whether malnutrition will prove to be more important.

Can Bioimpedance Measurements of Lean and Fat Tissue Mass Replace Subjective Global Assessments in Peritoneal Dialysis Patients?

OBJECTIVE: Malnutrition and protein energy wasting (PEW) determined by Subjective Global Assessment (SGA) is associated with increased mortality. There is an inverse relationship between body mass and overhydration in dialysis patients. Is the predictive accuracy of SGA (for death) independent of hydration status? Can bioimpedance spectroscopy analysis of lean tissue index (LTI) and fat tissue index (FTI) accurately identify dialysis patients with protein energy wasting and increased mortality? METHODS: We report an observational study of 455 peritoneal dialysis (PD) patients. RESULTS: We found that 96 patients (21%) were malnourished (SGA score between 1 and 5), and 192 (42%) had LTI values below 10th centile (age, gender adjusted). FTI was significantly lower in the SGA-defined malnourished cohort. By contrast, there was an inverse relationship between LTI and FTI. Malnourished (by SGA) patients were significantly more overhydrated (P < .0001), but SGA remained highly predictive of survival in multivariate analysis that included hydration status (hazard ratio: 3.12, 95% confidence interval 1.86-5.23, P < .0001). Obesity (patients with the highest 20% FTI) predicted survival (hazard ratio of death was 0.47, 95% confidence interval 0.16-0.85, P < .02) on univariate but not multivariate analysis. CONCLUSIONS: We have confirmed that SGA is an accurate predictor of mortality in PD patients, and its predictive value is independent of the hydration status. Predictive power of SGA was not affected when LTI and FTI were included in multivariate analysis. Patients with low LTI were different from patients with low SGA (associated with high FTI). Sensitivity and specificity of Body Composition Monitor to diagnose patients with low SGA readings were poor (area under the curve for receiver operator characteristics analysis 0.66). The phenomenon of reverse epidemiology (high FTI predicting a survival advantage) was found in our PD cohort.

Lack of motivation: a new modifiable risk factor for peritonitis in patients undergoing peritoneal dialysis?

AIM: Can we identify modifiable risk factors for peritonitis in patients undergoing peritoneal dialysis (PD)? We aimed to determine whether housing standard, PD exchange technique or patient motivation might be modifiable risks for peritonitis. We also explored the relationship between lack of motivation and depression. METHODS: Nurse home visits assessed PD exchange technique, environment and patient motivation. Motivation scores were correlated separately with an Apathy Evaluation Score and a depression score using PHQ-9 questionnaires. RESULTS: Home hygiene, exchange technique and motivation were above average in 53%, 56% and 60%, respectively in 104 patients undergoing PD. After 15 months, 25.9% patients developed peritonitis but nurses' ratings of homes and exchange techniques were not predictive. Low patient motivation was predictive. Patients rated to have above or below median motivation had significantly different Apathy Scores (p = 0.0002). Unmotivated depressed patients were significantly more likely to develop peritonitis compared to motivated depressed patients. CONCLUSION: Lack of motivation predicted peritonitis particularly if associated with depression. Further studies are required focusing on specific motivation scoring schemes and the psychosocial support that might lead to better outcomes.