bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterization of Subtypes of Hypertension in Capd Patients by Cyclic Guanosine Monophosphate
Authors: Lang Susanne M. , Wolfram Gernot , Gerzer Rupert , Schiffl Helmut
Published: February 2020

Objective

While most hypertensive patients with endstage renal disease normalize high blood pressure with fluid removal by continuous ambulatory peritoneal dialysis (CAPD), there is a significant proportion of CAPD patients whose blood pressure can be controlled only by antihypertensive drugs.

Method and Patients

To study the hypothesis that such patients are still volume overloaded, we used plasma cyclic guanosine monophosphate (cGMP) as a marker for hydration status. Thirty-two CAPD patients were divided into 3 groups: group 1, normotensive patients (n = 12); group 2, hypertensive patients who normalized their blood pressure with fluid removal (n = 12); group 3, hypertensive patients whose blood pressure was refractory to intensified fluid removal (n = 8).

Results

Mean cGMP levels were significantly higher in dialysis-sensitive hypertension (27 ± 5 pmol/mL) than in dialysis-refractory hypertension (15 ± 2 pmol/mL), or in normotensive patients (13 ± 4 pmol/mL). Reduction of excess fluid in volume overloaded hypertensive CAPD patients resulted in a normalization of cGMP levels (14 ± 8 pmol/mL), but did not affect this volume marker in patients with dialysis-resistant hypertension (10 ± 4 pmol/mL).

Conclusion

Plasma cGMP levels are elevated in volume overload-induced hypertension complicating CAPD. Hypertensive CAPD patients whose plasma cGMP levels are within normal limits have raised blood pressure refractory to volume removal. Our findings are consistent with the hypothesis that inadequate removal of excess volume plays a major role in a subset of patients with CAPD hypertension.
Gender Differences in Normalized Clearances in Capd: Role of Body Size and Normalizing Parameters
Authors: Tzamaloukas Antonios H. , Murata Glen H. , Bernardini Judith , Malhotra Deepak , Rao Panduranga , Piraino Beth , Oreopoulos Dimitrios G.
Published: February 2020

Objective

To compare raw (not normalized) and normalized urea and creatinine clearances between women and men on continuous ambulatory peritoneal dialysis (CAPD). To study whether potential gender differences are due to the normalization process.

Design

Retrospective analysis of clearance studies.

Setting

Dialysis units of four academic medical centers.

Participants

The study included 302 subjects (135 women and 167 men) on CAPD with four daily exchanges and a 2-L exchange volume.

Intervention

Measurement of urea and creatinine clearances (261 in women, 352 in men) by standard methods. Body water (the volume of distribution, V, for both urea and creatinine) was estimated by the Watson anthropometric formulas.

Main Outcome Measures

Comparison of raw and normalized clearances between women and men. Urea clearance was normalized by V (Kt/Vur), while creatinine clearances was normalized by both V (Kt/Vcr) and body surface area (BSA) (Ccr).

Results

Mean values of weekly total (peritoneal plus renal) raw clearances were higher in men (urea clearance: women 67.1 L, men 77.4 L; Ccr: women 61.7 L, men 78.3 L). Raw renal clearances were higher in men, while raw peritoneal clearances were comparable. Mean weekly total Kt/Vur was higher in women (2.19 vs 1.94 in men), mean weekly total Kt/Vcr did not differ between the genders (women 2.01, men 1.95), while mean weekly Ccr was higher in men (73.0 vs 64.7 L/1.73 m2 in women). When clearances differed, the differences were significant at p < 0.001. Men had greater height and weight, while women had greater body mass index. On the average, V in men exceeded V in women by 31%, while BSA in men exceeded BSA in women by only 12%.

Conclusions

Normalization of clearances by V creates relatively higher clearance values in women, while normalization by BSA creates relatively higher clearance values in men. Thus the normalization process may create artificial differences in the normalized clearances between genders.
Interleukin-1β Stimulates the Production of Extracellular Matrix in Cultured Human Peritoneal Mesothelial Cells
Authors: Yang Won Seok , Kim Byung Sik , Lee Sang Koo , Park Jung Sik , Kim Soon Bae
Published: February 2020

Objective

To investigate the effect of interleukin-1β (IL-1β) on the production of extracellular matrix in cultured human peritoneal mesothelial cells (HPMCs).

Design

Cultured HPMCs were treated with or without IL-1β. Cell morphology was observed. The expression of fibronectin, α1(I) procollagen, and transforming growth factor-β1 (TGFβ1) mRNAs was measured by Northern blot analysis. The cell surface expression of fibronectin and type I collagen was evaluated by immunofluorescent staining. Fibronectin and type I collagen in culture supernatant were measured by inhibition ELISA.

Results

Interleukin-1β induced morphologic change in HPMCs from a cuboidal epithelioid shape into an elongated fibroblastoid shape. The elongated cells were positive for cytokeratin although they had a fibroblastoid appearance. Treatment of HPMCs with IL-1β resulted in increased expression of both fibronectin and α1(I) procollagen mRNA in dose- and time-dependent manners. Immunofluorescent staining showed strong and diffuse cytoplasmic expression of fibronectin and type I collagen in the cells treated with IL-1β, whereas only weak perinuclear cytoplasmic staining was noted in the cells on media alone. The concentrations of secreted fibronectin and type I collagen in culture supernatant were significantly higher in the cells treated with IL-1β than in the control cells. IL-1β also stimulated the expression of TGFβ1 mRNA. However, IL-1β-induced fibronectin mRNA expression was only partially blocked by neutralizing anti-TGFβ antibody.

Conclusion

Interleukin-1β stimulated the production of extracellular matrix in cultured HPMCs along with the induction of morphologic changes. This may play a role in the development of peritoneal fibrosis caused by peritonitis or bioincompatible dialysate in continuous ambulatory peritoneal dialysis patients.
Effects of Amino Acid Dialysis Compared to Dextrose Dialysis in Children on Continuous Cycling Peritoneal Dialysis
Authors: Qamar Izhar U. , Secker Donna , Levin Leo , Balfe Judith A. , Zlotkin Stanley , Balfe J. Williamson
Published: February 2020

Objective

To compare the biochemical and nutritional effects of amino acid dialysis with dextrose dialysis in children receiving continuous cycling peritoneal dialysis (CCPD).

Design

A prospective randomized cross-over study.

Setting

Nonhospitalized patients.

Patients

Seven children aged 1.8 to 16.0 years (mean 8.1 years) with end-stage renal disease who were receiving CCPD.

Interventions

Each patient received nighttime automated CCPD of dextrose, plus a single daytime dwell of either amino acid dialysate or dextrose dialysate. After 3 months, subjects crossed over to the alternative regimen for a subsequent 3 months.

Main Outcome Measures

Creatinine clearance, ultra-filtration, urea, creatinine, electrolytes, total protein, albumin, fasting plasma amino acids, anthropometrics, total body nitrogen.

Results

Amino acid dialysis was comparable to dextrose dialysis for creatinine clearance and ultrafiltration. Plasma urea concentrations were higher during amino acid dialysis. No clinical side effects or worsening of metabolic acidosis was observed. Caloric intake increased and protein intake improved. Appetite and total body nitrogen increased in at least half the children during amino acid dialysis. Total plasma protein and albumin concentrations did not change significantly. Fasting plasma concentrations of amino acids after 3 months of amino acid dialysis were comparable to baseline values. For several amino acids, the dose-response curve was blunted after a single amino acid exchange following 3 months of amino acid dialysis, which may, in part, be due to the induction of hepatic enzyme synthesis.

Conclusions

Amino acid dialysis is an efficient form of peritoneal dialysis that should be considered for children with poor nutritional status for whom enteral nutrition supplementation has been unsuccessful. Further study is needed to determine the optimal amount of amino acids to deliver, the best time to administer the amino acid dialysis fluid, and the benefits of adding dextrose to the amino acid solution.
Peritonitis Due to Stenotrophomonas Maltophilia in Patients Undergoing Chronic Peritoneal Dialysis
Authors: Taylor Geoffrey , McKenzie Margaret , Buchanan–Chell Maureen , Perry Daisy , Chui Linda , Dasgupta Mrinal
Published: February 2020

The occurrence of cases of Stenotrophomonas maltophilia peritonitis in chronic peritoneal dialysis (PD) patients prompted a review of our experience with this condition. A search of microbiology records revealed seven episodes of S. maltophilia peritonitis in 7 patients in 1996 — 3.8% of all PD patients — compared to no cases in 1994 and 1995 ( p = 0.01). Patients ranged in age from 16 to 64 years; there were 3 males and 4 females. Six of seven episodes of peritonitis were community acquired and one was hospital acquired. No temporal clustering of cases was seen. Patients were from different urban and rural communities. Patients used the same commercially supplied dialysate fluid, different dialysis techniques, and were taught a no-touch technique for connection. Treatment of peritonitis required removal of the Tenckhoff catheter in 4 of 7 cases. Fingerprinting of six available isolates by polymerase chain reaction using primers derived from the conserved region of the 16/23Sr RNA gene sequence and pulsed field gel electrophoresis revealed all to be unique strains. A case-control study comparing 7 S. maltophilia cases to 21 PD controls showed case patients to be younger and more likely to be on immuno-suppressive therapy. We conclude that S. maltophilia has emerged as an important cause of peritonitis in our continuous ambulatory PD population. Evidence to date suggests community acquisition with no evidence of a common source.
Influence of Residual Renal Function on Dietary Protein and Caloric Intake in Patients on Incremental Peritoneal Dialysis
Authors: Caravaca Francisco , Arrobas Manuel , Dominguez Carmen
Published: February 2020

Objective

To evaluate protein and caloric intake in peritoneal dialysis (PD) patients on an incremental dialysis schedule, in an attempt to discriminate the influence of residual renal function (RRF) on these nutritional parameters.

Design

Prospective observational study.

Patients

Nine patients who had significant RRF at the beginning of PD therapy, which permitted a schedule of incremental PD (i.e., the number of peritoneal exchanges was increased as the RRF fell) in order to maintain the sum of renal and peritoneal clearance (weekly Kt/V urea) at approximately 2.

Methods

The mean adequacy parameters (urine and peritoneal Kt/V urea and creatinine clearance) along with the mean dietary energy (DEI) and protein intake (DPI) estimated by 3-day diet histories, were determined 6 and 9 months after the beginning of PD, when patients had RRF (period 1), and 6 and 9 months after the loss of RRF (period 2). The mean data obtained in both periods were compared. The best determinants for the changes in DEI and DPI after the loss of RRF were also investigated.

Results

Mean total Kt/V urea was very similar in both periods (2.16 ± 0.32 vs 2.15 ± 0.18), although creatinine clearance decreased significantly after the loss of RRF (74.41 ± 12.28 L/week/1.73 m2 vs 56.78 ± 11.77 L/week/ 1.73 m2, p = 0.0001). Absolute and normalized DPI values for actual body weight decreased after the loss of RRF (68.21 ± 11.87 g/kg vs 59.27 ± 13.66 g/kg, p = 0.02; and 1.17 ± 0.32 g/kg/day vs 0.97 ± 0.32 g/kg/day, p = 0.01). Although the energy delivered by peritoneal glucose uptake increased significantly after the loss of RRF, the mean total energy intake (DEI plus peritoneal glucose uptake) was very similar in both periods (2141 ± 339 kcal/day vs 2010 ± 303 kcal/day, p = 0.13). However, the mean total energy intake normalized for actual body weight decreased significantly after the loss of RRF (37.5 ± 10.1 kcal/ kg/day vs 32.8 ± 8.9 kcal/kg/day, p = 0.02). The changes in DEI and DPI between periods 1 and 2 correlated negatively with the difference of the energy delivered by peritoneal glucose uptake ( r = 0.65, p = 0.05, and r = 0.88, p = 0.001, respectively). The magnitude of DPI changes between both periods correlated significantly with the magnitude of urinary Kt/V urea changes ( r = 0.77, p = 0.01). However, there was no correlation between the changes in DPI and the changes in total Kt/V urea, total or renal creatinine clearance, or the length of time on PD.

Conclusions

The loss of RRF led to a reduction in dietary caloric and protein intake. The magnitude of the reduction in the DPI was strongly correlated with the increase in the energy delivered by peritoneal glucose uptake and with the decrease in the urinary Kt/V urea, but not with the total Kt/V urea.
The Risk of Infection and Peritoneal Catheter Loss from Implant Procedure Exit-Site Trauma
Authors: Crabtree John H. , Fishman Arnold , Siddiqi Rukhsana A. , Hadnott Linda L.
Published: February 2020

Objective

To evaluate the role of skin and subcutaneous tissue trauma at the time of catheter implant procedure as a determinant of catheter loss from infectious complications.

Design

Nonrandomized study with prospective collection of data.

Patients

Consecutive patients were divided into three groups based upon how the catheter was exited through the skin: group 1, procedure involved pulling tubing, with a permanently bonded catheter adapter, through the exit-site wound ( n = 43); group 2, same as group 1 except exit wounds were closed around the catheter with a suture ( n = 20); group 3, procedure involved pulling only tubing through the exit wound ( n = 61).

Setting

Primary medical center for a health maintenance organization.

Main Outcome Measures

Log rank comparisons of Kaplan–Meier analyses of first occurrences of infectious events and overall catheter survival.

Results

The risk of first exit-site infection ( p < 0.001), tunnel infection ( p < 0.001), catheter infection-related peritonitis ( p < 0.001), and catheter loss ( p < 0.01) were greatest in group 1 with large exit wounds, and lowest in group 3 with small exit wounds.

Conclusions

The study demonstrates the importance of careful dissection and exit-site construction. The exit site should consist of the smallest hole possible that permits passage of only the tubing and leaves the skin snug around the catheter. The present report incriminates catheter designs employing permanently bonded adapters that result in large pericannular wounds that are prone to infection and catheter loss.
Effect of Duration of Chronic Peritoneal Dialysis Therapy on the Development of Peritonitis
Authors: Troidle Laura , Gorban–Brennan Nancy , Kliger Alan S. , Finkelstein Fredric O.
Published: February 2020

Objective

Long-term chronic peritoneal dialysis (CPD) therapy has been associated with alterations in peritoneal membrane structure and peritoneal macrophage function. We thus reviewed our experience with the development of peritonitis among patients maintained on CPD therapy for various time periods to determine if the spectrum of organisms, rates of peritonitis, and outcome changed with the duration of CPD therapy.

Setting and Patients

Patients maintained on CPD therapy in our out-patient unit in New Haven, Connecticut.

Design

Retrospective review of the charts of patients maintained on CPD therapy (HomeChoice Cycler or Ultrabag, Baxter, McGaw Park, IL, U.S.A.) between 1 January 1997 and 31 March 1998. These patients were divided into three groups: group 1, patients maintained on CPD therapy < 12 months; group 2, patients maintained on CPD therapy for 13 - 36 months; and group 3, patients maintained on CPD therapy for ≥ 37 months.

Results

The study included 256 patients: 101 patients in group 1, 110 patients in group 2, and 45 patients in group 3. All groups of patients were similar in age. There were significantly fewer Caucasians and fewer males in group 3 in comparison to groups 1 and 2. The incidence of diabetes mellitus, coronary artery disease, and peripheral vascular disease was significantly lower among patients in group 3 in comparison to groups 1 and 2. There were 155 episodes of peritonitis during the study period for an overall rate of 1 episode in 18.7 patient-months. The overall, gram-positive, and gram-negative rates of peritonitis were not significantly different among the patients in groups 1, 2, and 3. There were more episodes of Staphylococcus aureus peritonitis among patients in group 3 in comparison to group 2 (1 episode in 59.6 vs 1 episode in 280.2 patient-months, respectively). Two weeks after the development of peritonitis, 94.6% of the patients in group 3 continued CPD therapy, while 79.4% of the patients in group 1 continued CPD therapy ( p < 0.05). No patient in group 3 transferred to hemodialysis, while 10.3% and 8.2% of the patients in groups 1 and 2 transferred to hemodialysis ( p < 0.05). The death rate 2 weeks after the onset of peritonitis was 10.3%, 9.8%, and 5.4% in groups 1, 2, and 3, respectively ( p = NS).

Conclusions

Despite the immunological and morphological changes that occur in the peritoneal cavity with increased time on CPD therapy, there was no difference in the overall, gram-positive, or gram-negative rates of peritonitis for patients maintained on CPD therapy for various time periods. Patients in group 3 continued CPD therapy more often than did patients in group 1. Patients in group 3 transferred to hemodialysis less often than did the remaining patients in the study period. The incidence of death was not significantly different for the three groups of patients.
Elimination of Iomeprol in Patients Undergoing Continuous Ambulatory Peritoneal Dialysis
Authors: Iwamoto Masako , Hiroshige Kinya , Suda Takeshi , Ohta Takayuki , Ohtani Akira , Nakashima Yasuhide
Published: February 2020

Objective

To examine the elimination of iomeprol, its safety in clinical use, and its peritoneal permeability in continuous ambulatory peritoneal dialysis (CAPD) patients with variable degrees of residual renal function (RRF).

Design

A nonrandomized comparison study.

Setting

Hospitalized patients in CAPD unit of Chikuho and University Hospitals.

Participants

Fourteen patients treated by CAPD and 6 by hemodialysis (HD).

Interventions

Total dialysate, blood, and 24-hour urine collections were obtained for 4 consecutive days after the administration of iomeprol. A peritoneal equilibration test was performed just before and after the administration of iomeprol.

Measurements

Iomeprol (iodine) concentration was measured. Residual renal function was estimated as the mean of renal creatinine and urea clearances. Dialysate-to-plasma ratios (D/P) of creatinine and iomeprol were also determined.

Results

In all CAPD patients, plasma iomeprol clearance was markedly slow, with a biological half-life ( T1/2) of over 32 hours. However, no patients suffered from any adverse effects, and over 80% of plasma iomeprol was eliminated during the 4-hour HD. The plasma iomeprol elimination rate was significantly higher from 4 hours after the iomeprol administration in CAPD patients with RRF [mean estimated creatinine clearance (CCr) 3.8 mL/min, n = 7] compared to the remaining patients (mean estimated CCr 0.6 mL/min, n = 7); however, T1/2 in patients with RRF was over 24 hours. D/P creatinine was significantly correlated with D/P iomeprol, and peritoneal iomeprol permeability may depend on an individual's peritoneal solute transport properties.

Conclusions

A prolonged elimination rate of iomeprol was documented in our CAPD patients both with and without RRF. A HD procedure or intensive peritoneal dialysis just after the use of iomeprol may be advisable to promptly remove circulating iomeprol.
Re-Evaluation of Solute Transport Groups Using the Peritoneal Equilibration Test
Authors: Rodby Roger A. , Firanek Catherine A. , Sarpolis Ann L.
Published: February 2020

Objective

To determine if the previously described peritoneal equilibration test (PET)-determined solute transport groups, as defined by Twardowski, fit our patient population.

Design

We reviewed the 195 initial standardized PETs (on 195 patients) performed through our peritoneal dialysis program since 1989. Using the method originally defined by Twardowski using the means and standard deviations of the PET-determined dialysis/plasma ratio (D/P) of creatinine and dialysate-to-0 hour dialysate (D/D0) glucose values, transport groupings for our patient population were determined. Comparisons were then made between patient populations.

Results

The mean 4-hour D/P creatinine in our patients was 0.70 ± 0.10. This compares to a mean of 0.65 ± 0.15 as determined by Twardowski, and indicates that our patients have higher mean solute transport characteristics and tighter ranges within transport groups than previously reported. Only 2% of our patients fell into the previously described low (L) range, with 30% low average (LA), 51% high average (HA), and 17% high (H). Using our data, we would redefine the groups by a 4-hour D/P creatinine as L < 0.60, LA = 0.60 – 0.70, HA = 0.70 – 0.80, and HA > 0.80. Using these values, our population fits a Gaussian distribution with 17% L, 31% LA, 33% HA, and 19% H.

Conclusion

Our patients have higher mean solute transport and tighter ranges within transport groups than previously reported. Using the previously defined PET-determined transport groupings, low transporters are particularly underestimated. If our population data are representative of the peritoneal dialysis population as a whole, these ranges should be redefined.
Validity of a Standard Information Protocol Provided to End-Stage Renal Disease Patients and Its Effect on Treatment Selection
Authors: Gómez Cristina Gil , Valido Pilar , Celadilla Olga , De Quirós Alfredo Granda Bernaldo , Mojón Modesta
Published: February 2020

Objective

To evaluate the validity of a standard information package, comprising written and audiovisual aids, for end-stage renal disease (ESRD) patients in a pre-dialysis program.

Study Design

A multicenter study comprising patients entering a predialysis program. Three questionnaires were developed to gather data in this study: (1) a pre-information package questionnaire that evaluates the patient's initial knowledge of ESRD and the treatment options available (pre-informed patients); (2) a post-information package questionnaire that evaluates the patient's knowledge of ESRD and treatment options after being informed according to the protocol (post-informed patients); (3) a “start of the treatment” questionnaire that deals with the patient's choice of treatment at the time of starting dialysis, as well as the reasons leading to that choice. In all three questionnaires the patient's age, gender, level of creatinine clearance (Ccr), and hematocrit were recorded.

Inclusion Criteria

Any patient who was on a predialysis program in the participating centers.

Results

Three hundred and four patients were evaluated across 14 participating centers. Initial knowledge was assessed in 216 pre-informed patients (questionnaire 1). Patients were then guided through the information package. One hundred and fifty-eight patients answered the post-information package (questionnaire 2). During the course of the study, 174 patients (of the initial 304) started renal replacement therapy. Of these, 49.4% (86 patients) had received predialysis information according to our study protocol. All the patients who received the information throughout the trial improved their knowledge of ESRD and treatment options; this improvement was statistically significant.

Conclusions

The treatment options least well known at the start of the study were the peritoneal dialysis techniques. After receiving the information package, patients had an equal knowledge of all the different treatments, although hemodialysis was still the most familiar. This improvement in knowledge enabled patients who started a dialysis treatment to choose a therapy according to their own preferences. Their selections were as follows: 44% of the patients chose hemodialysis, 40% chose continuous ambulatory peritoneal dialysis, and 16% chose automated peritoneal dialysis. The standard information package, used as a patient education program, effectively resulted in patients having a significantly improved level of knowledge and understanding of ESRD and the different treatment options available.
Vascular and Interstitial Changes in the Peritoneum of Capd Patients with Peritoneal Sclerosis
Authors: Mateijsen Maartje A.M. , Van Der Wal Allard C. , Hendriks Pascale M.E.M. , Zweers Machteld M. , Mulder Jos , Struijk Dirk G. , Krediet Raymond T.
Published: February 2020

Objective

To analyze morphological changes in the peritoneum of peritoneal sclerosis (PS) patients. Emphasis was put on vascular abnormalities, because the continuous exposure to glucose-based dialysis solutions could cause diabetiform changes and because longitudinal transport studies suggested the development of a large peritoneal vascular surface area.

Design

Peritoneal biopsies from continuous ambulatory peritoneal dialysis (CAPD) patients were investigated in two studies. Diabetic patients were excluded. In study 1, 11 PS biopsies were compared to three control groups varying in duration of CAPD treatment: 0 months ( n = 15), 2 – 25 months ( n = 7), and > 25 months CAPD ( n = 7). The second study was a case-control study, comparing six biopsies from the long-term control group to six PS biopsies, matched for age and duration of CAPD. All biopsies were scored for presence and type of fibrosis [Picro Sirius red, type IV collagen, α-smooth muscle actin (αSMA)] and for neoangiogenesis (factor VIII). Thickening of vascular walls by type IV collagen and vasodilation of capillaries were measured by computer-aided planimetry.

Results

In study 1 the presence of sclerosing fibrosis, deposition of interstitial type IV collagen, and the number of myofibroblasts (αSMA-positive cells) was greater in the PS biopsies than biopsies from all control groups ( p < 0.002). Moreover, the number of vessels per field was higher in PS biopsies ( p < 0.01). Vascular wall thickening of small arteries ( p < 0.008) and vasodilation of capillaries were found in PS biopsies compared to all control groups ( p < 0.007). The second study revealed differences in the presence of sclerosis but not in the extent of fibrosis between PS biopsies and their controls. The number of vessels per field in PS biopsies was higher compared to controls ( p = 0.04). Also, thickening of the vascular wall was more marked in PS biopsies ( p = 0.03). Vasodilation of capillaries was greater in PS biopsies than in controls ( p = 0.07).

Conclusion

Fibrosis of the peritoneum may precede peritoneal sclerosis. The deposition of type IV collagen and the presence of myofibroblasts in the interstitial layer could be part of a pathologic process similar to the scarring in diabetic nephropathy. Neoangiogenesis and thickening of the vascular wall by type IV collagen are consistent with glucose-induced microangiopathy. These abnormalities and the vasodilation of the capillaries can explain the high dialysate-to-plasma ratios or mass transfer area coefficients of low molecular weight solutes that can be found in long-term CAPD patients.
Recurrent Infection and Catheter Loss in Patients on Continuous Ambulatory Peritoneal Dialysis
Authors: Bayston Roger , Andrews Mark , Rigg Keith , Shelton Andrew
Published: February 2020

Objective

To elucidate the factors leading to catheter loss from recurrent infection in patients on continuous ambulatory peritoneal dialysis (CAPD).

Design

All catheters removed from patients were prospectively examined for infection.

Setting

CAPD unit in large tertiary-care general hospital.

Patients

Sixty-five consecutive patients undergoing catheter removal for whatever cause; 20 catheters rejected because of desiccation or contamination in transit.

Interventions

None.

Main Outcome Measures

Micro-organisms linked to catheter removal; their locations on removed catheters.

Results

Of 45 catheters removed between January 1994 and August 1995, 26 were infected: 13/26 infections were caused by Staphylococcus aureus and 7/26 by Pseudomonas aeruginosa. In only one case was S. epidermidis associated with catheter removal. The most striking finding was that the inner cuff harbored large numbers of the infecting organisms, even when antibiotics had eradicated them from the peritoneal cavity and exit site, where present, and the catheter lumen.

Conclusion

The importance of S. aureus and Ps. aeruginosa rather than S. epidermidis in catheter loss due to relapsing infection is confirmed. Persistence of the causative organisms in the inner cuff is a likely explanation for relapse after treatment, and might be due to the predominantly intraperitoneal administration of antibiotics. A clinical trial of the effect on catheter retention of empirical use of systemic or oral agents that give high tissue levels and are active against intracellular microorganisms, along with recommended intraperitoneal regimens, is indicated.
Follow-Up Study of Peritoneal Fluid Kinetics in Infants and Children on Peritoneal Dialysis
Authors: De Boer Alberdina W. , Van Schaijk Theodora C.J.G. , Willems Hans L. , De Haan Anton F.J. , Monnens Leo A.H. , Schröder Cornelis H.
Published: February 2020

Objectives

To study longitudinal changes in trans-capillary ultrafiltration (TCUF) and marker clearance (MC), as a reflection of lymphatic absorption, in children on peritoneal dialysis (PD). To present data on fluid kinetics in infants younger than 2.5 years, using an intraperitoneal volume of 1200 mL/m2 body surface area (BSA).

Design

The study involved a 4-hour dwell of 1200 mL/m2 BSA of dialysis fluid containing 3.86% glucose with Dextran 70 as volume marker. Cumulative TCUF and cumulative MC were measured.

Setting

A tertiary-care university hospital.

Patients

A follow-up period of 33 months of serial (1 – 4) peritoneal equilibration tests (PETs) was studied in 20 children with a median age of 6.4 years (range 2.1 – 15.4 years). Fluid kinetics in 5 additional infants with a median age of 1.4 years (range 0.5 – 2.5 years) was measured.

Results

Cumulative TCUF was 1041 mL/1.73 m2 at 1 – 3 months after start of PD, 1026 mL/1.73 m2 at 7 – 9 months, 1021 mL/1.73 m2 at 11 – 13 months, and 756 mL/ 1.73 m2 at 26 – 33 months (NS). Cumulative MC was 235 mL/1.73 m2 at 1 – 3 months after start of PD, 311 mL/ 1.73 m2 at 7 – 9 months, 395 mL/1.73 m2 at 11 – 13 months, and 509 mL/1.73 m2 at 26 – 33 months (NS). In infants, cumulative TCUF was 755 ± 237 mL/1.73 m2; cumulative MC was 400 ± 214 mL/1.73 m2.

Conclusions

Transcapillary ultrafiltration and marker clearance do not change in children > 2.5 years during the period studied. Fluid kinetics does not differ between infants < 2.5 years and older children when intraperitoneal volumes of 1200 mL/m2 BSA are used.
Comparison of Intraperitoneal and Subcutaneous Epoetin Alfa in Peritoneal Dialysis Patients
Authors: Johnson Curtis A. , Wakeen Maureen , Taylor Claude A. , Zimmerman Stephen W. , Burkart John , Bhattacharya Abhik , Kosorok Michael R.
Published: February 2020

Objective

To compare the efficacy of intraperitoneal (IP) and subcutaneous (SC) administration of epoetin alfa in patients receiving peritoneal dialysis (PD).

Design

A 32-week prospective, randomized, cross-over experimental design.

Setting

Two university-based outpatient PD centers.

Patients

Twenty adult PD patients receiving stable doses of SC epoetin alfa enrolled in the study. Thirteen patients completed 32 weeks of follow-up.

Intervention

Patients were randomly assigned to receive either SC or IP epoetin alfa at the start of the study. Dose adjustments were made to maintain baseline hematocrit ± 3 percentage points. Following 16 weeks of treatment, patients crossed over to the other route of administration for an additional 16 weeks. Intraperitoneal epoetin alfa was administered into an empty peritoneal cavity for approximately 8 hours before resuming dialysis. End-of-study IP epoetin alfa doses required to maintain target hematocrit were given twice weekly ( n = 1), once weekly ( n = 11), or once every other week ( n = 1). All patients received iron supplements to maintain or exceed prestudy iron parameters.

Main Outcome Measure

Prior to the study, the primary outcome measure was defined as the difference in epoetin alfa dose between IP and SC administration.

Results

Thirteen patients completed the study. The area under the dosing-requirement curve for IP epoetin alfa was larger than for SC administration ( p = 0.0029), and the slope of the 16-week dose-requirement curve was greater for IP administration ( p = 0.017), suggesting greater dose stability for SC administration. Paired analysis indicated greater IP intrapatient dose requirements ( p < 0.0001). The mean difference in SC versus IP doses was 5000 ± 1510 units per week. Some patients required escalating IP doses to maintain target hematocrit values. Iron administration and iron stores were similar in both groups.

Conclusion

Intraperitoneal epoetin alfa may be a suitable alternative for some patients for whom SC dosing is undesirable. Large IP versus SC dosing differences noted in a few patients are unexplained, but may result from interpatient variability in IP epoetin alfa absorption. Intraperitoneal dosing into an empty peritoneum can be done safely and effectively.
Changes in the Peritoneal Interstitium and Their Effect on Peritoneal Transport
Authors: Flessner Michael F.
Published: February 2020

Transperitoneal transport is a complicated process that includes diffusion and convection across the walls of blood microvessels into tissue interstitium, transport through the interstitium, and final passage across the peritoneum to the dialysis solution in the cavity. The purpose of this paper is to briefly review the normal physiology of this process and then to summarize the events that occur in response to inflammation within the cavity. These events begin with stimulation of macrophages, which in turn secrete cytokines. The cytokines stimulate mesothelial cells and fibroblasts in the tissue to synthesize and secrete other mediators. Those mediators initiate the complex events through which leukocytes migrate from blood vessel lumens through the interstitium and into the cavity. Much of the available data is from model in vitro systems, and therefore in vivo events must be deduced or hypothesized.
Impact of Peritoneal Membrane Function on Long Term Clinical Outcome in Peritoneal Dialysis Patients
Authors: Davies Simon J. , Phillips Louise , Griffiths Anne M. , Russell Lesley H. , Naish Patrick F. , Russel Gavin I.
Published: February 2020

It is increasingly clear that peritoneal membrane transport status has clinical implications. The role of the peritoneum in dialysis delivery becomes para mount once residual renal function is lost, particularly as the membrane characteristics may change for the worse with time on treatment. These findings have several important implications:

Clinicians need to take solute transport character istics into account as they assess their patients.

Adverse effects of high solute transport include reduced ultrafiltration, solute removal (in particular, sodium), and increased peritoneal protein losses.

A need exists to replace lost residual renal function, not just with enhanced solute removal, but also with adequate salt and water removal.

The interpretation of urea and creatinine clear ances in anuric PD patients needs further consideration and validation.

Hypoalbuminemia in PD patients will result from the combined effects of high protein losses, over hydration, comorbidity, and malnutrition.
Blood Flow Does Not Limit Peritoneal Transport
Authors: Flessner Michael F. , Lofthouse Joanne
Published: February 2020

Objective

We investigated the assumption that blood flow to the microvessels underlying the peritoneum does not limit solute or water exchange between the blood and the dialysis fluid.

Design

Small plastic chambers were affixed to the serosal side of the liver, cecum, stomach, and abdominal wall of anesthetized rats. Solutions that contained labeled solutes or that were made hypertonic were placed into the chambers, which restricted the area of transfer across the tissue to the base of the chamber and which permitted calculation of mass or water transfer rates on the basis of area. The local blood flow was monitored continuously with a laser Doppler flowmeter during three periods of observation: control, after 50% -70% reduction of the blood flow, and postmortem.

Results

Urea transfer across all serosa, except for the liver, showed no difference in mean mass transfer coefficient (cm/min) between control (0.0038 0.0046) and after 70% flow reduction (0.0037 -0.0040), but demonstrated a significant decrease with blood flow equal to zero (0.0020). These tissues demonstrated small but insignificant decreases in osmotic water flow into the chamber (0.7 -0.9 μL/min/cm2 under control conditions versus 0.4 -0.7 μL/min/cm2 with reduced blood flow). The liver demonstrated limitations in water and solute transport with a 70% decrease in blood flow.

Conclusion

Because the liver makes up a small part of the peritoneal area, we conclude that large drops in blood flow do not limit overall solute or water transfer across the peritoneum during dialysis, and therefore acute peritoneal dialysis may be an appropriate modality for ICU patients in shock and renal failure.
The Potential of Gene Therapy in the Peritoneal Cavity
Authors: Hoff Catherine M. , Shockley Ty R.
Published: February 2020

Gene therapy is a promising new treatment modality based on molecular genetic modification to achieve a therapeutic benefit. We believe that gene therapy in the peritoneal cavity holds considerable promise, and we describe strategies by which genetic modification can be used to treat a variety of disease states or conditions. First, we can envision a strategy, based on genetic modification of the peritoneal membrane, to improve the practice of peritoneal dialysis through the production of proteins that would be of therapeutic value in preventing membrane damage and in preserving or enhancing its function as a dialyzing membrane. Second, the membrane could be genetically modified for either local or systemic delivery of therapeutic proteins. This approach could be applied to a variety of pathologies or conditions that require either sustained or transient delivery of therapeutic proteins, such as enzymes or growth factors. Third, gene transfer has already been incorporated into several strategies for the treatment of intra-abdominal carcinomas, and it has been effective in animal models of ovarian and bladder cancer and of peritoneal mesothelioma. Finally, gene transfer can be a valuable tool in increasing our understanding of the biology of the peritoneal membrane. By being able to manipulate the expression of specific genes through gene transfer, their role in various (patho)physiological processes can be identified. In summary, gene therapy in the peritoneal cavity has significant potential to address a variety of diseases or pathophysiological conditions, and to further our knowledge of peritoneal cavity biology.
Neuropathy and Quality of Life in Diabetic Continuous Ambulatory Peritoneal Dialysis Patients
Authors: Apostolou Theofanis , Gokal Ram
Published: February 2020

Oiabetes mellitus is the commonest cause of end-stage renal failure and is associated with considerable morbidity. Neuropathy is one of the most serious complications of diabetes, linked to the incidence of nephropathy and retinopathy. The prevalence of neuropathy increases with age and duration of diabetes. Peripheral sensorimotor neuropathy is the main manifestation of neurological dam -age in diabetes, while autonomic neuropathy, a devastating complication, is also present in a large number of patients with long-term diabetes. Clinical features of autonomic neuropathy are mainly cardiovascular disorders and abnormal visceral function. One of the most important sequelae of neuropathy is the development of the insensitive foot at risk of ulceration, deformation, Charcot neuroarthropathy, and amputation. Prevention, education, and identification of the at-risk patient are the key elements in managing these severe complications. Oialysis, and mainly peritoneal dialysis, still remains the main renal replacement therapy for end-stage renal disease (ESRO) diabetic patients. It is obvious from many studies that diabetes and its complications are major risk factors associated with poorer survival rates, increased morbidity, and decreased quality of life. Few, if any, data are available specifically evaluating quality of life in continuous ambulatory peritoneal dialysis (CAPO) diabetic patients. Fewer data are available estimating the impact of neuropathy on the quality of life of such patients. Specific studies must be carried out to further investigate quality-of-life issues and neuropathy in this vulnerable group of patients.
Tuberculous Peritonitis
Authors: Prakash K.C.
Published: February 2020

Although the general incidence of peritonitis has declined considerably with improvement in connectology, tuberculous peritonitis is still a major problem in patients who are from endemic regions and who belong to high risk groups. The problem stems mainly from less sensitive diagnostic tools. Confirmation of tuberculous peritonitis is based on mycobacterial culture of the peritoneal fluid, which takes a few weeks. For patients in whom tuberculous peritonitis cannot be confirmed, therapeutic trial has been recommended.

Treatment of tuberculous peritonitis consists in removing the peritoneal catheter and initiating antituberculosis medications, though the dosage and duration of antituberculosis medication are not yet well defined. Early initiation of antituberculosis medication has been shown to preserve good ultrafiltration and solute clearance by the peritoneal membrane.
Effects of Peritoneal Rest on Peritoneal Transport and Peritoneal Membrane Thickening in Continuous Ambulatory Peritoneal Dialysis Rats
Authors: Kim Yong-Lim , Kim Sung-Ho , Kim Jun-Hong , Kim Seog-Jae , Kim Chan-Duck , ChO Dong-Kyu , Kim Yong-Jin , Moberly James B.
Published: February 2020

Objective

To evaluate the effects of peritoneal rest on peritoneal transport and morphology in a rat model of peritoneal dialysis.

Design

Twenty-four rats (Sprague-Dawley, male, 250 300 g) were divided into three groups: group 1 (control, n = 6) without dialysis, group 2 (n = 9) sacrificed immediately after 3 weeks of dialysis, and group 3 (n = 9) sacrificed after 4 weeks of peritoneal rest after 3 weeks of dialysis. Both dialysis groups were dialyzed twice daily with an intraperitoneal instillation volume of 25 mL of 3.86% dextrose solution for 3 weeks. Peritonitis was induced by supplementing the dialysis fluid with lipopolysaccharide (5 μg/mL) on days 8, 10, and 12 in both dialysis groups. Peritoneal equilibration tests were performed on each animal at baseline. The equilibration tests were repeated at the 4th and the 8th week of dialysis. Morphometric analyses of the peritoneal membrane were carried out in tissue specimens obtained at the time of sacrifice.

Results

The DIDo ratio for glucose at two hours in groups 2 and 3 at the beginning of week 4 was significantly lower than at baseline, indicating an increase in peritoneal permeability to glucose after 3 weeks of dialysis. DIDo in group 3 at the beginning of week 8, after 4 weeks of peritoneal rest, was significantly higher than at week 4. The drain volume in groups 2 and 3 at week 4 was significantly lower than at baseline; however, the drain volume in group 3 at week 8 was significantly higher than at week 4. The thickness of the parietal peritoneal membrane in group 3 was significantly greater than in group 1 and less than in group 2 (group 1, 11.4 ± 7.6 μm; group 2, 37.5 ± 18.4 μm; group 3,21.4 ± 12.1 μm).

Conclusions

Peritoneal rest improves ultrafiltration in rats by decreasing the hyperpermeability of glucose and also reduces the degree of peritoneal thickening. These data suggest that dialysis -induced changes in peritoneal transport and morphology are reversible under the conditions of peritoneal rest in this experimental model.
Socioeconomic Aspects of Peritoneal Dialysis in North America: Role of Non Medical Factors in the Choice of Dialysis
Authors: Venkataraman Vijaya , Nolph Karl D.
Published: February 2020

Patients initiating dialysis therapy must make a choice between hemodialysis (HD) and peritoneal dialysis (PD). Controversy persists over the relative merits of each modality in the treatment of end-stage renal disease (ESRD). Issues relating to survival, morbidity, economics, and patient characteristics will all determine the final choice of therapy. Non medical factors are the most important determinant of dialysis modality selection.

In the United States, HD has been the more commonly used modality, while PD is underrepresented. This disparity arises from multiple factors including reactions (sometimes incorrect) to the healthcare financing structure, physician biases, and changing demographic patterns in the ESRD population. We discuss these issues and present collected evidence showing that increased use of PD may have substantial overall benefit.
Individualized Prescription of Peritoneal Dialysis Therapy
Authors: Blake Peter G.
Published: February 2020

Prescribing PD has become more challenging, but also more rewarding and stimulating in recent years. The number of technical aids and strategies has increased, and a potential exists to optimize clearances and ultrafiltration in a way that has not been seen before and that will, it is to be hoped, translate into better patient outcomes. It is crucial, however, that the technologies and strategies be applied with an awareness of the individual patient's particular lifestyle, aspirations, and social circumstances. A failure to consider these factors may lead to noncompliance and, ultimately, to “burnout” and technique failure. Patients must be educated about the importance of clearance targets so that they will accept the alterations in, or the onerous aspects of, the prescriptions they require. Successful prescribing of PD requires an awareness of both clearance and lifestyle factors so that the two can be integrated to give an effective and acceptable regimen. Finally, cost factors should also be considered.