The effect of peritoneal rest in combination therapy of peritoneal dialysis and hemodialysis: using the cultured human peritoneal mesothelial cell model

Effects of incremental peritoneal dialysis with low glucose-degradation product neutral pH solution on clinical outcomes

PURPOSE

Incremental peritoneal dialysis (IPD) could decrease unfavorable glucose exposure results and preserve (RKF). However, there is no standardization of dialysis prescriptions for patients undergoing IPD. We designed a prospective observational multi-center study with a standardized IPD prescription to evaluate the effect of IPD on RKF, metabolic alterations, blood pressure control, and adverse outcomes.

METHODS

All patients used low GDP product (GDP) neutral pH solutions in both the incremental continuous ambulatory peritoneal dialysis (ICAPD) group and the retrospective standard PD (sPD) group. IPD patients started treatment with three daily exchanges five days a week. Control-group patients performed four changes per day, seven days a week.

RESULTS

A total of 94 patients (47 IPD and 47 sPD) were included in this study. The small-solute clearance and mean blood pressures were similar between both groups during follow-up. The weekly mean glucose exposure was significantly higher in sPD group than IPD during the follow-up (p < 0.001). The patients with sPD required more phosphate-binding medications compared to the IPD group (p = 0.05). The rates of peritonitis, tunnel infection, and hospitalization frequencies were similar between groups. Patients in the sPD group experienced more episodes of hypervolemia compared to the IPD group (p = 0.007). The slope in RKF in the 6th month was significantly higher in the sPD group compared to the IPD group (65% vs. 95%, p = 0.001).

CONCLUSION

IPD could be a rational dialysis method and provide non-inferior dialysis adequacy compared to full-dose PD. This regimen may contribute to preserving RKF for a longer period.

Changes in erythropoiesis-stimulating agent responsiveness after transfer to combined therapy with peritoneal dialysis and hemodialysis for patients on peritoneal dialysis: A prospective multicenter study in Japan

INTRODUCTION

Inadequate dialysis and fluid overload are corrected after starting combined therapy with peritoneal dialysis (PD) and hemodialysis (HD). However, the effects on anemia management has not been elucidated.

METHODS

We conducted a prospective, multicenter, observational cohort study of 40 PD patients (age, 60 ± 10 years; male, 88%; median PD duration, 28 months) starting combined therapy and investigated changes in several clinical parameters, including erythropoiesis-stimulating agent (ESA) resistance index (ERI).

RESULTS

ERI decreased significantly during 6 months after switching to combined therapy (from 11.8 [IQR 8.0-20.4] units/week/kg/(g/dL) to 7.8 [IQR 3.9-18.6] units/week/kg/(g/dL), p = 0.047). Body weight, urinary volume, serum creatinine and the dialysate-to-plasma creatinine ratio (D/P Cr) decreased, whereas hemoglobin and serum albumin increased. In subgroup analysis, the changes in ERI were not affected by cause for starting combined therapy, PD holiday and D/P Cr.

CONCLUSION

Although detailed mechanism was unclear, ESA responsiveness improved after switching from PD alone to combined therapy.

Peritoneal Dialysis Guidelines 2019 Part 1 (Position paper of the Japanese Society for Dialysis Therapy)

Approximately 10 years have passed since the Peritoneal Dialysis Guidelines were formulated in 2009. Much evidence has been reported during the succeeding years, which were not taken into consideration in the previous guidelines, e.g., the next peritoneal dialysis PD trial of encapsulating peritoneal sclerosis (EPS) in Japan, the significance of angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs), the effects of icodextrin solution, new developments in peritoneal pathology, and a new international recommendation on a proposal for exit-site management. It is essential to incorporate these new developments into the new clinical practice guidelines. Meanwhile, the process of creating such guidelines has changed dramatically worldwide and differs from the process of creating what were “clinical practice guides.” For this revision, we not only conducted systematic reviews using global standard methods but also decided to adopt a two-part structure to create a reference tool, which could be used widely by the society’s members attending a variety of patients. Through a working group consensus, it was decided that Part 1 would present conventional descriptions and Part 2 would pose clinical questions (CQs) in a systematic review format. Thus, Part 1 vastly covers PD that would satisfy the requirements of the members of the Japanese Society for Dialysis Therapy (JSDT). This article is the duplicated publication from the Japanese version of the guidelines and has been reproduced with permission from the JSDT.

Peritoneal Dialysis Solutions Low in Glucose Degradation Products—evidence for Clinical Benefits

In Japan, two types of new peritoneal dialysis fluid (PDF) are ordinarily used: two-chambered PDF, and icodextrin PDF. Two-chambered PDF has several biocompatible characteristics, one being low glucose degradation products (GDPs). Of the several GDPs in PDF, 3,4-dideoxyglucosone-3-ene (3,4-DGE) is thought to be strongly associated with the cytotoxicity of standard PDF. Using a PDF low in GDPs may reduce exposure of the peritoneum to 3,4-DGE, helping to preserve peritoneal function in PD patients. Additionally, use of a PDF low in GDPs may reduce plasma levels of advanced glycosylation end-products in PD patients, a change that may help to preserve vascular function in PD patients.

Peritoneal rest for 24 hours after exposure to a PDF with low GDPs improves the activity of human peritoneal mesothelial cells. As compared with the use of standard PDF, the use of low-GDP PDF in combination therapy (peritoneal dialysis plus hemodialysis) may more effectively preserve peritoneal function. The new PDF low in GDPs has bio-compatible characteristics relative to peritoneum and system that may help to preserve peritoneal function or reduce complications such as atherosclerosis or dialysis-related amyloidosis in dialysis patients.

APD or CAPD: one glove does not fit all

The use of Automated Peritoneal Dialysis (APD) in its various forms has increased over the past few years mainly in developed countries. This could be attributed to improved cycler design, apparent lifestyle benefits and the ability to achieve adequacy and ultrafiltration targets. However, the dilemma of choosing the superior modality between APD and Continuous Ambulatory Peritoneal Dialysis (CAPD) has not yet been resolved. When it comes to fast transporters and assisted PD, APD is certainly considered the most suitable Peritoneal Dialysis (PD) modality. Improved patients’ compliance, lower intraperitoneal pressure and possibly lower incidence of peritonitis have been also associated with APD. However, concerns regarding increased cost, a more rapid decline in residual renal function, inadequate sodium removal and disturbed sleep are APD’s setbacks. Besides APD superiority over CAPD in fast transporters, the other medical advantages of APD still remain controversial. In any case, APD should be readily available for all patients starting PD and the most important indication for its implementation remains patient’s choice.

Preserved peritoneal function by short-term two-day peritoneal rest in hemodialysis combination therapy patients

Several reports have demonstrated that peritoneal rest (PR) is considered to preserve the peritoneal function in peritoneal dialysis (PD) patients. However, there has been no report that examines the peritoneal permeability before and after a short-term PR of two days. We examined the effect of the two-day PR on peritoneal permeability. We observed and compared the daily PD ultrafiltration changes in the four PD and hemodialysis (HD) combination patients from the start of dialysis therapy throughout the total observation period of each case. Next, 6 months after the initiation of dialysis therapy we performed a set of peritoneal equilibrium tests (PET) before and after the 2-day PR. D/P creatinine, daily urine volume, daily ultrafiltration volume in PD, weekly residual renal creatinine clearance, and weekly PD creatinine clearance were measured. The daily PD ultrafiltration volume increased significantly after the 2-day PR, and gradually decreased over the last four days throughout the observation period in each patient. In the PET results, D/P creatinine in all patients decreased after the short-term PR, and accordingly the peritoneal ultrafiltration volume increased. However, urine volume, residual renal creatinine clearance, and peritoneal creatinine clearance did not change. The peritoneal permeability clearly decreased after the short-term PR. The repeated improvement in the PD ultrafiltration volume after the short-term PR implies that the peritoneal permeability alteration might be due to a reversible functional change in the initial dialysis period. These results suggest that a short-term PR may preserve the peritoneal function.

Effects of Peritoneal Resting on Peritoneal Fluid Transport Kinetics

Background

Peritoneal resting has been used to restore peritoneal ultrafiltration capacity in peritoneal dialysis patients. Therefore, in the present study, we made a detailed investigation on the effects of peritoneal resting on peritoneal fluid transport characteristics in patients on continuous ambulatory peritoneal dialysis (CAPD).

Methods

A temporary transfer to daytime ambulatory peritoneal dialysis with a nocturnal “empty belly” was applied to let the peritoneal membrane rest overnight in patients with poor ultrafiltration capacity. All included patients were asked to record appropriately their dialysis exchanges for the assessment of peritoneal fluid transport characteristics, which were evaluated before and after peritoneal resting.

Results

Seven CAPD patients were included in the present study. There was a significant improvement in peritoneal ultrafiltration capacity as assessed by ultrafiltration volume per gram of glucose load. Patients’ daily glucose exposure and dialysate-to-plasma ratio of creatinine were significantly decreased after peritoneal resting. The peritoneal fluid absorption rate was also significantly decreased after peritoneal resting: 1.011 ± 0.4484 versus 0.625 ± 0.3833 mL/minute.

Conclusion

The present study suggests that peritoneal resting can improve CAPD patients’ ultrafiltration capacity and decrease the use of hypertonic dialysis solution. The improved ultrafiltration capacity by peritoneal resting was due to decreased membrane solute transport rate and decreased peritoneal fluid absorption rate.

Patient Selection for Automated Peritoneal Dialysis: For Whom, When?

The use of the various forms of automated peritoneal dialysis (APD) has increased considerably in the past few years. This increase has in part been driven by technology, through improved cycler design. Other contributing factors include better adjustment of APD to patient lifestyle, the flexibility that APD offers to patients, and the increased ability of APD to achieve adequacy and ultrafiltration targets. For high transporters and for patients unable to perform peritoneal dialysis (PD) on their own (for example, pediatric and elderly patients), APD is considered the most suitable PD modality. Furthermore, APD has been associated with improved compliance, lower intraperitoneal pressure, and lower incidences of peritonitis. On the other hand, concerns have been raised regarding increased complexity and cost, a more rapid decline in residual renal function, inadequate sodium removal, and disturbed sleep. Automated PD is an alternative to continuous ambulatory PD when a higher dialysis dose is needed, and it could be a reliable alternative for unplanned or urgent dialysis start. Other than beneficial results in high transporters, the medical advantages of APD remain controversial. Individual patient choice therefore remains the main indication for the application of APD, which should be made available to all patients starting PD.

The Effects of Colchicine on the Progression and Regression of Encapsulating Peritoneal Sclerosis

Background

Encapsulating peritoneal sclerosis (EPS) is an infrequent but extremely serious complication of long-term peritoneal dialysis. Fibrosis of the submesothelial compact zone and neoangiogenesis underlie the pathophysiology of EPS. Colchicine is a well-known anti-inflammatory and antifibrotic agent that has been used for some fibrosing clinical states, such as liver fibrosis.

Objective

To determine the antifibrotic and anti-inflammatory effects of colchicine in an EPS rat model in both progression (P) and regression (R).

Methods

48 nonuremic albino Wistar rats were divided into 5 groups: control group, 2 mL isotonic saline intraperitoneally (IP) daily for 3 weeks; CG group, IP injection of 2 mL/200 g chlorhexidine gluconate (CG) (0.1%) and ethanol (15%) dissolved in saline, daily for 3 weeks; resting group, CG (0 – 3 weeks) + peritoneal resting (4 – 6 weeks); C-R group, CG (0 – 3 weeks) + 1 mg/L colchicine (4 – 6 weeks); C-P group, CG (0 – 3 weeks) + 1 mg/L colchicine in drinking water (0 – 3 weeks). At the end, a 1-hour peritoneal equilibration test was performed with 25 mL 3.86% peritoneal dialysis solution. Dialysate-to-plasma ratio of urea (D/P urea), dialysate WBC count, ultrafiltration volume, and morphological changes of parietal peritoneum were examined.

Result

Exposure to CG for 3 weeks resulted in alterations in peritoneal transport (increased D/P urea, decreased ultrafiltration volume; p < 0.05) and morphology (increased inflammation, neovascularization, fibrosis, and peritoneal thickness; p < 0.05). Resting had some beneficial effects on peritoneal derangements; however, once the peritoneum had been stimulated, resting alone was not enough to reverse these pathological changes. Colchicine had more pronounced effects on membrane integrity via decreased inflammation, cell infiltration, and vascularity compared to the resting group.

Conclusion

We suggest that colchicine may have therapeutic value in the management of EPS.

The Effects of Renin–angiotensin System Inhibition on Regression of Encapsulating Peritoneal Sclerosis

Background

Encapsulating peritoneal sclerosis (EPS) is a clinical syndrome associated with symptoms of ileus and irreversible sclerosis of both visceral and parietal peritoneum. Peritoneal dialysis (PD) patients rarely develop EPS, a severe life-threatening condition of unknown pathogenesis. Angiotensin II is known to promote fibrosis and inflammation in various tissues. Renin–angiotensin system (RAS) blockade provides advantages in the course of diseases such as hypertension, chronic kidney disease, and proteinuria. We have also previously shown that RAS blockade has beneficial effects on hypertonic (3.86%) PD solution-induced peritoneal alterations. Because it shares the same characteristics as other fibrotic processes, peritoneal fibrosis can benefit from RAS blockade.

Objective

To determine the advantages of RAS blockade in regression of EPS.

Methods

We divided 56 nonuremic albino Wistar rats into 6 groups: control group ( n = 10), daily intraperitoneal (IP) injection of 2 mL isotonic saline for 3 weeks; CG group ( n = 10), daily IP injection of 2 mL/200 g chlorhexidine gluconate (CG) for 3 weeks; resting group ( n = 10), daily IP injection of CG (0 – 3 weeks) plus peritoneal rest (4 – 6 weeks). After 3 weeks of being injected with CG (0 – 3 weeks), a fourth group ( n = 9) was treated with 100 mg/L enalapril (ENA group); a fifth group ( n = 10) was treated with 80 mg/L valsartan (VAL group), and a sixth group ( n = 7) was treated with 100 mg/L enalapril + 80 mg/L valsartan (ENA+VAL group) in drinking water for an additional 3 weeks (4 – 6 weeks). At the end, a 1-hour peritoneal equilibration test was performed with 25 mL 3.86% PD solution. Dialysate-to-plasma ratio of urea (D/P urea), dialysate WBC count, ultrafiltration volume (UF), and morphological changes of parietal peritoneum were examined.

Results

Exposure to CG for 3 weeks resulted in alterations in peritoneal transport (increased D/P urea, decreased UF volume; p < 0.05) and morphology (increased inflammation, neovascularization, fibrosis, and peritoneal thickness; p < 0.05). Peritoneal rest had some beneficial effect only on UF failure and dialysate cell count ( p < 0.05). However, RAS blockade was more effective than peritoneal rest with respect to UF volume, vascularity ( p < 0.05), and peritoneal thickness ( p > 0.05). Dual blockade of RAS had no additional beneficial effects.

Conclusion

We suggest that RAS blockade either with angiotensin-converting enzyme inhibitors or angiotensin receptor blockers may be a more effective option than resting in the management of EPS.

Clinical application of computer-aided diagnostic system for harmonious introduction of complementary dialysis therapy

In chronic peritoneal dialysis (PD) therapy, peritoneal permeability is gradually enhanced over the duration of the therapeutic course, leading to a grave decline in the therapeutic efficiency. In recent years, a novel therapy (CD therapy), which integrates PD therapy with hemodialysis therapy, is being applied to end-stage PD patients to complement the decline of therapeutic efficiency caused by the grave degeneration of the peritoneal tissue. To realize a harmonious introduction of the CD therapy, this study developed a useful index (KAu/c), which evaluates both therapeutic efficiency and degeneration of peritoneal tissue. Using a mathematical model and KAu/c, we were able to validate the therapeutic efficiency in the PD patients, and, in one case, propose a better prescription for the patient by employing the CD therapy. The clinical implementation of this methodology is indispensable with regard to expanding the therapeutic monitoring system for renal replacement therapy.