Ultrafiltration in Patients on Automated Peritoneal Dialysis with Homechoice Claria connected to Sharesource: A Pilot Study

Introduction: Fluid overload is an unavoidable problem in patients on peritoneal dialysis (PD) and is associated with poor outcomes. The aim of our study was to estimate ultrafiltration (UF) under different dextrose concentrations and clarify possible predictors of UF.Materials and methods: Seventy patients, with 1848 daily treatment records and 8266 single dwells on automated PD through Homechoice Claria with Sharesource were followed in October 2020 and categorized into 2 groups according to the dextrose concentration (group D1.5% and D2.5%). Baseline characteristics, peritoneal membrane characteristics, and daily PD treatment records from Sharesource were obtained. We compared UF under the different conditions.Results: Multivariate linear regression revealed that the mean fill volume (FV) per cycle (p=0.006) and dextrose concentration (p=0.000) were independent predictors of UF. The mean night UF per cycle, the mean night UF corrected by FV per cycle, and the mean night UF corrected by FV and dwelling time (DT) per cycle were 95.8 ml, 5.5%, and 5.0 ‱/minutes in group D1.5% and 220.3 ml, 12.0%, and 11.6 ‱/minutes in group D2.5%, respectively. After an approximately 120-minute DT, there was a trend toward higher UF in the low peritoneal permeability group and lower UF in the high peritoneal permeability group.Conclusion: This retrospective study presents precise UF measurements with two solutions at different dextrose concentrations and four peritoneal transport levels. UF is positively correlated with DT and FV of the dialysate within a reasonable range. High peritoneal permeability is associated with decreased UF, and low peritoneal permeability requires a longer DT to reach the maximal UF.

Hyaluronan reduces colitis-induced intraperitoneal inflammation during peritoneal dialysis

Background: Peritoneal dialysis induces the inflammatory response within the peritoneal cavity, which contributes to the progressive damage of the peritoneum. Due to close contact of the peritoneal cavity and the intestines, there is the possibility that the visceral disorders can affect the intraperitoneal inflammation during peritoneal dialysis. Objectives: Study of the effect of acute colitis on the intraperitoneal inflammation in conditions of peritoneal dialysis and evaluation of the protective effect of hyaluronan in that scenario. Methods: In rats with the dextran sulphate-induced colitis, 6-h peritoneal dialysis was performed with dianeal 2.5% +/− hyaluronan 10 mg/dL. In the control group, rats without colitis were studied. Peritoneal permeability and dialysate inflammation were studied at the end of the dialysate exchange. Results: In rats with colitis, intraperitoneal inflammatory reaction was increased as compared with the control group and reflected by the following studied parameters: dialysate cell count (+26%, p < 0.01), number of neutrophils (+75%, p < 0.01), generation of free radicals in the leukocytes (+70%, p < 0.05), dialysate level of elastase (+102%, p < 0.01), tumor necrosis factor α (+48%, p < 0.01) and monocyte chemoattractant protein-1 (+42%, p < 0.01). Drained dialysate volume was lower (−21%, p < 0.01) and peritoneal permeability increased in rats with colitis (+55%, p < 0.01). In animals with the hyaluronan supplemented dialysis fluids, the intensity of the intraperitoneal inflammation was reduced. Conclusions: Visceral inflammation during colitis induces the inflammatory reaction within the peritoneal cavity that may accelerate damage to the peritoneum. Supplementation of the dialysis fluid with hyaluronan reduces the intensity of that effect.

Comparison of patient survival and technique survival between continuous ambulatory peritoneal dialysis and automated peritoneal dialysis

Background: This retrospective cohort study compared patient survival and technique survival between patients on continuous ambulatory peritoneal dialysis (CAPD) and automated peritoneal dialysis (APD) using recent data at a single tertiary medical center in Taiwan. Methods: From medical records, we identified incident 459 CAPD patients and 266 APD patients on dialysis for at least 90 days and aged more than 18 years to estimate mortality and technique failure rates, and related hazard ratio (HR) and 95% confidence interval (CI) from 2007 to 2018. Results: There were more women (52.3%) in the CAPD group, whereas patients in the APD group were younger. Compared to CAPD patients, APD patients had a lower mortality rate (2.83 vs. 5.79 per 100 person-years) with an adjusted HR of 0.69 (95% CI = 0.47–1.02), and a lower technique failure rate (9.70 vs. 17.52 per 100 person-years) with an adjusted HR of 0.65 (95% CI = 0.51–0.83). Further subgroup analyses revealed that, compared to CAPD, APD was associated with a significant lower risk of technique failure in male patients, patients aged 50–65 years, diabetic patients, patients without cardiovascular disease (CVD), patients with higher peritoneal permeability, or patients initiating PD in an earlier era. Conclusions: The mortality risk was not significant between CAPD and APD patients. APD is associated with a lower risk of technique failure than CAPD, particularly for male patients, and patients aged 50–65 years, with diabetes, without CVD, with high or high average peritoneal permeability, or initiating PD in an earlier era.

P1195ASSESSMENT OF BODY FLUID VOLUME USING THE BIOIMPEDANCE METHOD IN PERITONEAL DIALYSIS PATIENTS

Background and Aims ppropriate maintenance of body fluid balance in peritoneal dialysis (PD) patients is important for the amelioration of cardiovascular complications and prognosis. In recent years, the usefulness of body fluid measurement with the bioimpedance method in PD patients has been reported. Meanwhile, peritoneal permeability plays an important role in maintaining body fluid balance in PD patients. In the present study, we examined the correlation between peritoneal permeability and body fluid volume in PD patients. Method A total of 58 patients who were undergoing PD at our hospital (42 men and 16 women; mean age, 68 ± 16.2 years; mean dialysis history, 63.5 ± 144.9 months; 25 DM and 35 non-DM patients). Overhydration (OH), total body water (TBW) volume, extracellular water (ECW) volume, and lean tissue mass (LTM) were measured using a body composition analyzer (BCM Fresenius Medical Care Japan). At the same time, peritoneal permeability was measured with fast peritoneal equilibration test to determine the dialysate-to-plasma ratio for creatinine (D/P-Cr), and its correlations with sex, age, age at the time of introduction of dialysis, dialysis history, diabetes history, brain natriuretic peptide (BNP) level, high-sensitivity troponin I (hsTnI) level, blood pressure, body weight, residual kidney function, and ultrafiltration were examined. Results The mean OH was 2.53 ± 2.44 L, and 8 patients (13.8%) had an OH of ≤1.1 L. The results of the multivariate analysis revealed that OH positively correlated with the presence or absence of diabetes, ultrafiltration, D/P-Cr, BNP level, hsTnI level, TBW, and ECW, but showed no correlation with sex, dialysis history, age, age at the time of introduction of dialysis, residual renal function, or LTM. Furthermore, the subjects were assigned to D/P-Cr ≥ 0.65 and ≤0.65 groups. In the former, OH correlated with diabetes and male sex by being negatively correlated with age and age at the time of introduction of dialysis and positively correlated with BNP level, hsTnI level, TBW, and ECW. However, in the D/P-Cr ≤ 0.65 group, OH positively correlated with BNP level and ECW. Conclusion Our results suggest that youth, complications of DM, and men are at risk for fluid overload in PD patients with increased peritoneal permeability.

Long-term sonographic evaluation of the peritoneum in peritoneal dialysis patients: A retrospective cohort study

Background Long-term peritoneal dialysis (PD) causes morphological changes to the peritoneum. However, the sequential morphological changes of the peritoneum remain unclear due to the invasiveness and ethical dilemmas surrounding peritoneal biopsies. We aimed to evaluate these long-term morphological peritoneal changes using sonography, which was recently reported to be useful for morphological peritoneal evaluation. Methods We retrospectively identified 115 PD patients who underwent sonographic peritoneal membrane thickness (PMT) measurement. Univariate and multivariate linear regression analyses identified factors related to PMT at baseline (bPMT), at last measurement (lPMT), and the PMT change rate. Of the 115 patients, 42 patients had at least two PMT measurements, including a bPMT measurement. We evaluated the PMT change between bPMT and lPMT. We also evaluated the annual PMT change for 3 years before PD withdrawal in patients who discontinued PD due to peritoneal dysfunction. Clinical characteristics and parameters were analyzed according to PMT change rates (≤ 0 [n = 28] or > 0 [n = 20]). Results The mean age at PD introduction and mean PD duration were 63.7 ± 12.7 years and 40.5 ± 30.1 months, respectively. There was a significant positive correlation between the dialysate to plasma ratio of creatinine (D/P Cr) and lPMT (r = 0.386, p = 0.004), but not bPMT (r=-0.114, p = 0.326). In the multivariate analyses, D/P Cr remained an independent predictor of lPMT (r = 0.478, p = 0.001) after adjusting for age, sex, body mass index, PD duration, diabetes, and peritonitis rate. The mean bPMT and lPMT were 0.67 ± 0.15 mm and 0.69 ± 0.10 mm, respectively, without statistical difference (p = 0.49). Annual PMTs for 3 years before PD withdrawal were 0.67 ± 0.13 mm, 0.66 ± 0.11 mm, and 0.67 ± 0.08 mm, respectively, with no significant differences among measurements (p = 0.967). There were no differences in PD duration, the use of a dialysate containing over 2.5% glucose or icodextrin, and the peritonitis rate between groups divided by the PMT change rate. Conclusions PMT, measured by sonography, was positively correlated with peritoneal permeability. Repeated evaluation of the peritoneum by sonography will enable the recognition of transition in peritoneal function in real time and allow for more appropriate PD management. Furthermore, the peritoneum was not necessarily thickened regardless of PD duration or cause of withdrawal.

Clinical relevance of marginal factors on ultrafiltration in peritoneal dialysis

Background: Ultrafiltration (UF) in peritoneal dialysis (PD) is mainly driven by the osmotic gradient and peritoneal permeability, but other factors—such as intraperitoneal pressure (IPP)—also have an influence. Methods: To assess the clinical relevance of these marginal factors, we studied 41 unselected PD patients undergoing two consecutive 2 h, 2.27% glucose exchanges, first with 2.5 L and then with 1.5 L. Results: IPP, higher in the 2.5 L exchange, had a wide interpatient range, was higher in obese and polycystic patients and their increase with infusion volume was higher for women regardless of body size. UF with 2.5 L correlated inversely with IPP and was higher for patients with polycystosis or hernias, while for 1.5 L we found no significant correlations. The effluent had higher glucose and osmolarity in the 2.5 L exchange than in the 1.5 L one, similar for both sexes. In spite of this stronger osmotic gradient, only 21 patients had more UF in the 2.5 L exchange, with differences up to 240 mL. The other 20 patients had more UF in the 1.5 L exchange, with stronger differences (up to 800 mL, and more than 240 mL for 9 patients). The second group, with similar effluent osmolarity and peritoneal equilibration test (PET) parameters than the first, has higher IPP and preponderance of men. The sex influence is so intense that men decreased average UF with 2.5 L with respect to 1.5 L, while women increased it. Conclusions: With 2.27% glucose, sex and IPP—modulated by obesity, polycystosis, hernias, and intraperitoneal volume—significantly affect UF in clinical settings and might be useful for its management.

Alterations of Intercellular Junctions in Peritoneal Mesothelial Cells from Patients Undergoing Dialysis: Effect of Retinoic Acid

BackgroundDialysis patients are classified according to their peritoneal permeability as low transporter (LT, low solute permeability) or high transporter (HT, high solute permeability). Tight junction (TJ) proteins are critical to maintain ions, molecules and water paracellular transport through peritoneum. Exposure to peritoneal dialysis solutions causes damage to TJ in human peritoneal mesothelial cells (HPMCs). We analyzed the quantity, distribution and function of TJ proteins: claudin-1, -2 and -8, ZO-1 and occludin, in HPMC cultures from LT and HT patients. Since all-trans retinoic acid (ATRA) might modify the expression of TJ proteins, we studied its effect on HPMCs.MethodsControl HPMCs were isolated from human omentum, while HT or LT cells were obtained from dialysis effluents. Cells were cultured in presence of ATRA 0, 50 or 100 nM. Transepithelial electrical resistance (TER) measurement, immunostaining and Western blot analyses were performed.ResultsHT exhibited lower TER than control and LT monolayers. Immunofluorescence for TJ was weak and discontinuous along the cell contour, in LT and HT. Furthermore, claudin- 1, occludin and ZO-1 expressions were decreased. In all groups, claudin-2 was localized at nuclei. We observed that ATRA improved TJ distribution and increased TJ expression in HT. This retinoid did not modify claudin-2 and -8 expressions. All-trans retinoic acid decreased TER in HT, but had no effect in LT.ConclusionsTight junctions were altered in HPMCs from dialyzed patients. The HT monolayer has lower TER than LT, which might be associated with the peritoneal permeability in these patients. ATRA might be a therapeutic alternative to maintain mesothelial integrity, since it improved TJ localization and expression.