Risk factors and clinical outcomes of encapsulating peritoneal sclerosis: A case–control study from China

Background: Encapsulating peritoneal sclerosis (EPS) is an uncommon, but serious complication in patients with continuous ambulatory peritoneal dialysis (PD) who have a considerable mortality rate. This study aimed to identify risk factors and outcomes of EPS in Chinese patients on PD. Methods: Sixteen patients on PD who met the International Society for Peritoneal Dialysis criteria for diagnosis of EPS in the First Affiliated Hospital of Sun Yat-Sen University from 1997 to 2018 were included. Patients without EPS were matched for age, sex and the duration of PD and selected at a 1:3 ratio for the controls. A case–control study was conducted to analyse the clinical profile and risk factors associated with EPS in patients. Results: The prevalence of EPS in patients on PD in our centre was 0.55%. The percentage of EPS significantly increased with the duration of PD. In univariate regression analysis, a history of peritonitis (odds ratios (OR): 2.83; 95% confidence interval (CI): 0.82–9.68; p = 0.08), peritoneal glucose exposure (OR: 1.12; 95% CI: 1.03–1.22; p < 0.01) and a high peritoneal transport status (OR: 14.70; 95% CI: 1.85–117.02; p < 0.01) were associated with EPS in patients on PD. However in the multivariate model, only a high peritoneal transport status (adjusted odds ratios (aOR): 13.65; 95% CI: 1.69–109.96; p = 0.01) was independently associated with EPS. Conclusion: The rate of EPS significantly increases with the duration of PD. Progressive peritoneal dysfunction, especially a high peritoneal transport status, is associated with a higher risk of EPS in this population.

MO699PERITONITIS RISK OF PD MODALITIES AND TECHNICAL SURVIVAL ACCORDING TO BASELINE PERITONEAL TRANSPORT STATUS

Background and Aims The PD modality is usually modulated according to the PET and dialysis adequacy during follow-up but, initial modality choice generally depends on patient preferences and lifestyle regardless of patients’ baseline transport status. However, the relationship between baseline transport status, the PD modality chosen, and technical survival is not well established. Peritonitis is one of the leading causes of technical failure, hospitalization, and death in PD. While obesity, low albumin levels, exit-site infections, and nasal staphylococcus carriage are well-defined risk factors for peritonitis, some suggest CAPD could be another risk factor due to increased daily connection to PD. Many studies indicated that CAPD and APD have similar technical survival rates. In this study, we aimed to identify the impact of the baseline transport status on technical survival of CAPD and APD. We also investigated peritonitis risk of modalities considering all defined risk factors. Method This is a retrospective, single-center, cohort study of incident adult PD patients followed-up between January 2010 and January 2020. One hundred and thirty-six patients, followed-up for at least three years, were included. Patients with malignancy and who had less than 1.7 Kt/V per week were excluded. Peritonitis is defined according to the "International Society Peritoneal Dialysis" guideline. According to the baseline PET, patients were divided into two groups as follows; 1) high or high average transporters and 2) low or low average transporters. Risk factors for peritonitis, five years, and overall technical survival of both modalities according to baseline transport status were determined. Results The mean age was 35.5±12 years, and the median follow-up time was 47 (36-178) months. Sixty-six (48%) of the patients were female. Patients' first-year Kt/V per week was 2.18±0.4, and the mean ultrafiltration was 0.9±0.4 liters. 26 (19%) of the patients had diabetes mellitus, 57(42%) patients had hypertension, and 27 (20%) of the patients had a history of hemodialysis of more than three months. 89 (65%) of the patients were performing CAPD, 59 (66%) of whom were low or low-average transporters. 47(35%) of patients were performing APD and 28(60%) of whom were high or high-average transporters. During the follow-up, a total of 71 peritonitis episodes were observed, and the incidence of peritonitis was 0.13 episodes/year. Univariate logistic regression analysis showed that CAPD, low education level (being primary school graduate or illiterate), HD treatment before PD, and bathing less than once per week were associated with peritonitis risk. However, multivariate analysis of associated factors demonstrated that only CAPD was a significant risk factor for peritonitis [odds ratio:2.360 (95% confidence interval:1.075-5.180), p=0.03]. Kaplan-Meier survival analysis showed that low or low-average transporters and high or high-average transporters had similar technical survival rates in both CAPD or APD at the end of three years (figure 1). Similar rates were found in overall survival. Conclusion In our study, APD and CAPD patients had similar technical survival regardless of the peritoneal transport characteristics. However, CAPD was found to be a factor for peritonitis. Thus, it may be appropriate to initiate the PD treatment with APD modality and evaluate patients to switch modalities with PET only in case of peritoneal dialysis inadequacy.

MO714MEAN PLATELET VOLUME / PLATELET COUNT RATIO IN PERITONEAL DIALYSIS: ASSOCIATION TO PERITONEAL TRANSPORT STATUS

Background and Aims Mean platelet volume volume (MPV) is gaining scientific interest with regard to cardiovascular risk stratification. The MPV/platelet count ratio seems to be more specific than mean platelet volume alone as a surrogate parameter for platelet activation. The MPV/platelet ratio might be of interest in peritoneal dialysis (PD) as the distribution and integrity of endothelial – platelet interaction in the abdominal space determines its function. The aim of the study was to evaluate the associations between MPV/platelet ratio and peritoneal transport status. Method In 123 PD patients (median age 65 years) MPV and platelet count were measured together with anthropometric patient data and peritoneal function at catheter placement and after 6 months during the first peritoneal equilibration test (PET). MPV and platelet count were determined with a fully-automated hematological analyzer. Correlation analysis was performed. Results The MPV/platelet ratio decreased significantly from 3.99% at placement to 3.50% at the first PET (median values, Wilcoxon test p&lt;0.001). Neither anthropometric data, nor creatinine clearance, nor BUN clearance, nor Kt/V (renal, peritoneal, total), nor erythrocyte sedimentation rate, nor C reactive protein were associated to MPV/platelet ratio. Only D/P urea and D/P creatinine were significantly correlated to MPV/platelet ratio (D/P urea r=0.223, p=0.01; D/P creatinine r=0.199, p=0.03). Slow transporters presented a significantly lower MPV/platelet ratio than average transporters (median values, 3.49% versus 3.83%, Mann-Whitney test p=0.03). Conclusion Peritoneal dialysis is reducing significantly the MPV/platelet ratio. Differences in MPV/platelet ratio are reflected in the peritoneal transport status at 6 months after dialysis start. The reduction of the MPV/platelet ratio might respect a reduced platelet and endothelial activation even in the abdominal space.

Effects of Peritoneal Dialysis on QT Interval in ESRD Patients

Background: Patients with chronic kidney disease (CKD) had a high risk of fatal arrhythmias. The extended corrected QT (QTc) interval is a hallmark of ventricular arrhythmias and sudden cardiac death. Studies have shown that QT interval and QTc were prolonged with the declination in renal function. Notably, QTc prolongation is significantly increased in patients undergoing hemodialysis. However, there were no results available in patients with peritoneal dialysis (PD). This study aimed to report the changes in QT interval and QTc in PD patients.Methods: A total of 66 PD patients were enrolled. The duration of follow-up was 1 year. The demographics, and the etiology of patients were recorded. QTc of ECG and clinical biochemical indexes before dialysis and at 6 months after PD and 1year after PD were determined and analyzed. Dialysis adequacy and peritoneal transport function were assessed in each patient.Results: (1) A total of 66 PD incident patients, including 50 males and 16 females, with an average age of 43.56±15.15 years (males: 43.74±15.53 years; females: 43.00 ± 15.92 years) were enrolled. In terms of etiology, 37 patients (56.06%) had chronic nephritis, followed by diabetic nephropathy in 11 patients (16.67%), IgA nephropathy with 8 patients (12.12%). The peritoneal transport test showed that the most of the peritoneal transport function was low average transport( 25, 37.88%), the least was high transport(2, 3.03%).(2) During the follow-up period, all patients reached the standard of PD. Compared with baseline before dialysis, anemia, low albumin, blood pressure, blood urea nitrogen, creatinine, uric acid, potassium, calcium, phosphorus and parathyroid hormone were improved after PD at 6 months and 1year. The residual renal function was gradually decreases during the follow-up. There were no significant differences in clinical indexes between 6 months and 1 year after PD.(3) The mean QTc of all patients were stable during 1-year follow-up period (pre-PD: 413.49±29.95ms; 6 months: 423.05±51.96ms; 1 year: 409.29±32.32ms, P>0.05). According to gender, the QTc in male patients and in female patients had the same results (P>0.05, respectively).(4) Before PD, diastolic blood pressure (r=-0.261,P=0.039), calcium concentration (r=-0.360,P=0.004) and hemoglobin level (r=-0.432,P=0.000) were found to be the risk factors of QTc prolongation. They were negatively correlated with QTc in end-stage renal disease patients. After patients starting PD, the observed clinical indicators showed no relevance to QTc anymore.Conclusion: Different from hemodialysis induced QTc prolongation, PD did not increase the patient's QT interval and QTc interval. This phenomenon was reported for the first time, suggesting that myocardial electrical activity might be more stable in PD patients.

On the change of transport parameters with dwell time during peritoneal dialysis

The transitory change of fluid and solute transport parameters occurring during the initial phase of a peritoneal dialysis dwell is a well-documented phenomenon; however, its physiological interpretation is rather hypothetical and has been disputed. Two different explanations were proposed: (1) the prevailing view—supported by several experimental and clinical studies—is that a vasodilatory effect of dialysis fluid affects the capillary surface area available for dialysis, and (2) a recently presented alternative explanation is that the molecular radius of glucose increases due to the high glucose concentration in fresh dialysis fluid and that this change affects peritoneal transport parameters. The experimental bases for both phenomena are discussed as well as the problem of the accuracy necessary for a satisfactory description of clinical data when the three-pore model of peritoneal transport is applied. We show that the correction for the change of transport parameters with dwell time provides a better fit with clinical data when applying the three-pore model. Our conclusion is in favor of the traditional interpretation namely that the transitory change of transport parameters with dwell time during peritoneal dialysis is primarily due to the vasodilatory effect of dialysis fluids.