Unusual and complicated peritonitis: Your questions answered

Effective treatment of infections is a growing challenge owing to antimicrobial resistance. Peritoneal dialysis (PD) patients experience more frequent hospitalisations than the general population and have greater exposure to antibiotics, making them particularly vulnerable to this threat. Over the last decade, we have noted a surge in cases of complicated peritoneal dialysis-associated peritonitis (PD peritonitis) caused by antimicrobial-resistant organisms, including extended-spectrum beta-lactamase (ESBL), AmpC beta-lactamase-producing Enterobacterales, Pseudomonas aeruginosa and fungi. Practitioners must be alert to these organisms, seek early recognition of these resistance patterns and make timely adjustments in order to avoid delay in treatment that may increase risk of PD catheter removal and technique failure. We present a case of successful treatment of ESBL peritonitis, highlight its challenges, while providing guidance on management of other unusual and complicated PD peritonitis.

The Removal of Uremic Solutes by Peritoneal Dialysis

ABSTRACT

Peritoneal dialysis (PD) is now commonly prescribed to achieve target clearances for urea or creatinine. The International Society for Peritoneal Dialysis has proposed however that such targets should no longer be imposed. The Society's new guidelines suggest rather that the PD prescription should be adjusted to achieve well-being in individual patients. The relaxation of treatment targets could allow increased use of PD. Measurement of solute levels in patients receiving dialysis individualized to relieve uremic symptoms could also help us identify the solutes responsible for those symptoms and then devise new means to limit their accumulation. This possibility has prompted us to review the extent to which different uremic solutes are removed by PD.

Peritoneal Dialysis Prescription and Adequacy in Clinical Practice: Core Curriculum 2023

As the global prevalence of peritoneal dialysis (PD) continues to grow, practitioners must be equipped with prescribing strategies that focus on the needs and preferences of patients. PD is an effective form of kidney replacement therapy that offers numerous benefits to patients, including more flexibility in schedules compared with in-center hemodialysis (HD). Additional benefits of PD include salt and water removal without significant changes in patient hemodynamics. This continuous yet gentle removal of solutes and fluid is associated with better-preserved residual kidney function. Unfortunately, sometimes these advantages are overlooked at the expense of an emphasis on achieving small solute clearance targets. A more patient-centered approach emphasizes the importance of individualized treatment, particularly when considering incremental PD and other prescriptions that align with lifestyle preferences. In shifting the focus from small solute clearance targets to patient needs and clinical goals, PD remains an attractive, patient-centered form of kidney replacement therapy.

Care of the hospitalised patient receiving peritoneal dialysis: Your questions answered

Peritoneal dialysis (PD) patients have higher hospitalisation rates than the general population. The hospitalisations are not always related to dialysis issues, and physicians with little or no experience with PD may be responsible for the care of these hospitalised patients. Furthermore, the hospital may not be familiar with or equipped to manage these patients. This review highlights barriers, knowledge gaps and management strategies to guide the care of hospitalised PD patients.

Anxiety and psychosocial impact during coronavirus disease 2019 in home dialysis patients

The severe acute respiratory syndrome coronavirus (SARS-Cov-2) resulting in the coronavirus disease 2019 (COVID-19) is documented to have a negative psychosocial impact on patients. Home dialysis patients may be at risk of additional isolating factors affecting their mental health. The aim of this study is to describe levels of anxiety and quality of life during the COVID-19 pandemic among home dialysis patients. This is a single-centre survey of home dialysis patients in Toronto, Ontario. Surveys were sent to 98 home haemodialysis and 43 peritoneal dialysis patients. Validated instruments (Haemodialysis and Peritoneal Dialysis Treatment Satisfaction Questionnaire, Generalized Anxiety Disorder 7 Item [GAD7] Scale, Patient Health Questionnaire [PHQ-9], Illness Intrusiveness Ratings Scale, Family APGAR Questionnaire and The Self Perceived Burden Scale) assessing well-being were used. Forty of the 141 patients surveyed, participated in September 2020. The mean age was 53.1 ± 12.1 years, with 60% male, and 85% home haemodialysis, 80% of patients rated their satisfaction with dialysis at 8/10 or greater, 82% of respondents reported either "not at all" or "for several days" indicating frequency of anxiety and depressive symptoms, 79% said their illness minimally or moderately impacted their life, 76% of respondents were almost always satisfied with interactions with family members, 91% were never or sometimes worried about caregiver burden. Among our respondents, there was no indication of a negative psychosocial impact from the pandemic, despite the increased social isolation. Our data further supports the use of home dialysis as the optimal form of dialysis.

Incremental peritoneal dialysis in incident end-stage kidney disease patients

BACKGROUND

This retrospective cohort study investigated the characteristics and outcomes of the end-stage kidney disease (ESKD) patients treated with incremental peritoneal dialysis (PD) at a large academic centre.

METHODS

ESKD patients initiating PD with a dialysate volume ≤6 L/day were analysed.

RESULTS

One hundred and seventy-five patients were included and were followed up for 352.6 patient-years. The baseline residual kidney function (RKF) was 8.3 ± 3.4 mL/min/1.73 m². The unadjusted 1- to 5-year patient survival rate was 89.6%, 80.4%, 65.4%, 62.7% and 48.8%, respectively, and the corresponding time on PD therapy rate was 95.1%, 89.1%, 89.1%, 82.4% and 77.6%. Greater initial PD dose (hazard ratio = 1.608, 95% confidence interval 1.089-2.375) was associated with death after adjusting for age, Charlson comorbidity index (CCI), haemodialysis prior to PD, assisted PD and baseline RKF, likely as a result of residual confounding. There was no association with PD discontinuation. The average peritonitis rate and hospitalisation rate were 0.122 and 0.645 episodes per patient-year, respectively. The dialysate volume increased from 4.5 (4.3-5.7) L/day to 8.0 (6.0-9.8) L/day at 5 years. Fifty-seven (32.6%) patients graduated to full-dose PD at a median time of 10.3 (6.2, 15.7) months. Male sex, greater body mass index and lower baseline serum albumin were risk factors for increasing PD dose to over 6 L/day within 1 year.

CONCLUSIONS

Incremental PD is a safe approach to initiate dialysis, and it offers satisfactory outcomes. Close monitoring, comprehensive evaluation of clinical responses and prompt adjustment of the prescription as needed play a crucial role in this patient-centred treatment.

A Comparison of Hemodialysis and Peritoneal Dialysis in Patients with Cardiovascular Disease

The high prevalence of cardiovascular disease is caused by the traditional cardiovascular risk factors common among end-stage renal disease patients, and nontraditional risk factors attributed to underlying kidney disease, including chronic inflammation, anemia, bone mineral disease, and the dialysis procedure itself. Individualization of the treatment of cardiovascular disease in end-stage renal disease that could impact the underlying mechanisms of the cardiovascular diseases is important to improve outcomes. This article reviews and compares hemodialysis and peritoneal dialysis in association with different cardiovascular diseases affecting dialysis patients, including hypertension, coronary artery disease, myocardial stunning, cardiac arrhythmias, heart failure, and the cardiorenal syndrome.

Home-to-home dialysis transition: A 24-year single-centre experience

Home dialysis (peritoneal dialysis (PD) and home haemodialysis (HHD)) are ideal options for kidney replacement therapy (KRT). Occasionally, because of technique failure, patients are required to transition out of home dialysis, and the most common option tends to be to in-centre HD. There are few published studies on home-to-home transition (PD to HHD or HHD to PD) and dynamics during the transition period. We present a retrospective review of 28 patients who transitioned from a home-to-home dialysis modality at our centre over a 24-year period. We observed a total of 911 home dialysis patients with technique failure (826 PD patients and 85 HHD patients) with only 28 patients (3% of the total with technique failure) having successful home-to-home transition. During the transition period, 11 patients (39%) were hospitalized and 13 patients (46%) required variable periods of in-centre HD. After a median follow-up of 48 months following dialysis modality transition, four patients switched to in-centre HD permanently (home dialysis technique survival of 86% censored for death and kidney transplantation) and four patients died resulting in a patient survival of 86% (censored for switch to in-centre HD and transplantation). In our centre, home-to-home transition is a feasible strategy with comparable patient and technique survival. A significant proportion of patients switching from a home-to-home dialysis modality required variable intervals of hospitalization and in-centre HD during transitions. Future efforts should be directed towards assessment and home dialysis education during the entire process of dialysis transition.

The use of virtual physician mentoring to enhance home dialysis knowledge and uptake

Home dialysis therapies are flexible kidney replacement strategies with documented clinical benefits. While the incidence of end-stage kidney disease continues to increase globally, the use of home dialysis remains low in most developed countries. Multiple barriers to providing home dialysis have been noted in the published literature. Among known challenges, gaps in clinician knowledge are potentially addressable with a focused education strategy. Recent national surveys in the United States and Australia have highlighted the need for enhanced home dialysis knowledge especially among nephrologists who have recently completed training. Traditional in-person continuing professional educational programmes have had modest success in promoting home dialysis and are limited by scale and the present global COVID-19 pandemic. We hypothesize that the use of a 'Hub and Spoke' model of virtual home dialysis mentorship for nephrologists based on project ECHO would support home dialysis growth. We review the home dialysis literature, known educational gaps and plausible educational interventions to address current limitations in physician education.

A Single-Center Retrospective Study on the Initiation of Peritoneal Dialysis in Patients With Cardiorenal Syndrome and Subsequent Hospitalizations

Background:

Inotropic dependence and diuretic resistance in patients with cardiorenal syndrome (CRS) lead to frequent hospitalizations and are associated with high mortality. Starting peritoneal dialysis (PD) acutely (within 2 weeks of a heart failure hospitalization) offers effective volume removal without hemodynamic compromise in this population. There is little data on this approach in the North American literature.

Objective:

To determine whether volume-overloaded patients with CRS on maximal doses of diuretic therapy had reduced hospitalization for heart failure following PD initiation.

Design:

Retrospective cohort study.

Setting:

Academic hospital network (University Health Network, Toronto, Ontario).

Patients:

Patients with CRS receiving a bedside catheter and starting PD within 2 weeks of insertion at the University Health Network from January 1, 2013, to December 31, 2018.

Methods and measurements:

Data for heart failure–related hospitalizations and length of stay 6 months before and after PD initiation were collected. Patients who died, switched to hemodialysis, or were transferred to another facility within 6 months of starting PD were excluded from the analysis.

Results:

We identified 31 patients with CRS who had a bedside PD catheter inserted. The average age of patients was 66.0 ± 13.0 years. There were 7 (22.6%) deaths and 4 (12.9%) transfers to other programs or hemodialysis within 6 months of catheter insertion. After exclusion, we analyzed hospitalization and length of stay data for 20 patients. The hospitalization rate 6 months before PD initiation was 6.9 admissions per 1000 patient-days. This decreased to 2.5 admissions per 1000 patient-days after PD initiation. In addition, there was also a significant reduction in the average length of stay per hospitalization (24.1-3.9 days; P = .001).

Limitations:

Our study did not assess the severity of heart failure symptoms using a standardized functional classification system. We did not assess quality of life and illness intrusiveness scores before and after starting dialysis, nor did we capture non–heart-failure-related hospitalizations or external admissions at other hospital sites. We limited eligibility to clinically stable patients with no prior major abdominal surgical history in a single Canadian PD program using bedside ultrasound approach for catheter insertions by experienced nephrologists and included a small number of patients.

Conclusions:

Volume-overloaded patients with CRS receiving maximal diuretic therapy have lower hospitalization rates and shorter stays after initiation of PD. The development of a bedside PD catheter insertion program and close collaboration between nephrology and cardiology services may facilitate acute start dialysis in this population.

Home Hemodialysis and Peritoneal Dialysis Patient and Technique Survival in Canada

INTRODUCTION

As interest for home dialysis is growing, knowledge of comparative clinical outcomes between peritoneal dialysis (PD) and home hemodialysis (HHD) would help to better inform shared decision making with patients and caregivers during modality discussion. This study aimed to assess differences in risk of mortality and technique failure in an incident home dialysis cohort and, specifically, to assess change in this association through eras.

METHODS

All adults patients initiating PD or HHD, in Canada (excluding Quebec), within 365 days after kidney replacement therapy (KRT) initiation between 2000 and 2013 were included (administrative censoring 31 December 2014). Mortality and treatment failure (transfer to another modality for >90 days or death) were assessed in a multivariable Cox proportional hazard model, with prespecified stratification based on the year of KRT initiation.

RESULTS

The study included 959 HHD and 15,469 PD patients. Compared with incident PD, incident HHD was associated with a lower risk of mortality (adjusted hazard ratio [aHR] = 0.64, 95% confidence interval [CI] = 0.53-0.78), and treatment failure (aHR = 0.52, 95% CI = 0.45-0.60). These lower risks of mortality with HHD were more pronounced for older cohorts (2000-2005: aHR = 0.47, 95% CI = 0.31-0.70; 2006-2010: aHR = 0.70, 95% CI = 0.54-0.89) and not significantly different in the most recent era (2011-2013: aHR = 0.86, 95% CI = 0.51-1.47).

CONCLUSION

In Canadian incident KRT patients, HHD was associated with appreciably lower risks of mortality and treatment failure compared to PD, although this association appeared to be attenuated in the most contemporary era.

Utility of Abdominal Imaging in Peritoneal Dialysis Patients Presenting With Peritonitis

Background

Peritonitis remains a major complication in peritoneal dialysis (PD). Abdominal imaging is often performed in the setting of peritonitis to evaluate for concomitant intra-abdominal processes. However, the usefulness of this procedure is unknown.

Objective

The aim of this study was to assess the prevalence of abdominal imaging performed in the setting of PD peritonitis and to evaluate clinical parameters associated with abnormal imaging results to identify clinical situations in which radiographic examinations are informative.

Design

This is a retrospective cohort study.

Setting

The study was conducted at the Toronto General Hospital, Ontario, Canada.

Patients

We studied 166 episodes of PD peritonitis in 114 patients between January 1, 2011, and June 30, 2016.

Measurements

Baseline demographics, characteristics of PD peritonitis, and characteristics of abdominal imaging performed.

Methods

The association between relevant clinical parameters and abnormal abdominal imaging was examined using a univariate and multivariate logistic regression model.

Results

Abdominal imaging (computed tomography [CT] scan or ultrasound) was performed in 68 cases (41%). Patients were more likely to undergo imaging if they required hospitalization, were admitted to the intensive care unit (ICU), had polymicrobial or fungal organisms causing peritonitis, had relapsing/recurrent/refractory peritonitis, had an indication for hemodialysis or PD catheter removal, or presented with hypotension, tachycardia, or an elevated serum lactate. Of the imaging performed, abnormalities were found in 32 cases (47%). The most common findings were bowel obstruction, intra-abdominal collection, and biliary abnormalities. In the univariate analysis, ICU admission (43.3% vs 14.3%, P < .01) and need for temporary or permanent hemodialysis (62.5% vs 30.6%, P < .01) were associated with imaging abnormalities. Importantly, the peritonitis organism was not associated with abnormal imaging results. In a multivariate analysis, ICU admission was the only significant clinical parameter associated with imaging abnormalities with an odds ratio (OR) of 4.4 (95% confidence interval [CI]: 1.1-17.4, P = .04).

Limitations

Single-center study, small sample size, and lack of detailed information on the exact indications leading to abdominal imaging.

Conclusions

Abdominal imaging is commonly performed in the setting of PD peritonitis. Abnormalities are not infrequent and are present in almost half of the cases, with need for ICU admission being the most significant clinical parameter associated with abnormal findings. Therefore, abdominal imaging should be performed in carefully selected patients with PD peritonitis, especially if there is evidence of hemodynamic instability. While the finding of fungal or polymicrobial peritonitis was a driver for abdominal imaging, the presence of these organisms did not predict radiologic abnormalities.

The Rationale and Ultimate Limitations of Urea Kinetic Modelling in the Estimation of Nutritional Status

Objective

This paper reviews protein flux and amino acid metabolism and the potential inaccuracies inherent in using urea kinetics as an estimate of these processes, particularly in the patient undergoing peritoneal dialysis. The problems of extrapolating these estimates back to the whole patient are examined, addressing assumptions about neutral nitrogen balance, and the difficult issue of normalizing urea-derived indices to body size.

Conclusions

Urea kinetics can be a helpful tool for assessing nutritional indices, but there are many caveats and many pitfalls that must be kept in mind to avoid being lulled into a false sense of confidence by the comfort of numbers.

Chiropody May Prevent Amputations in Diabetic Patients on Peritoneal Dialysis

← Background

A multidisciplinary approach has been shown to be of benefit in the prevention of lower limb ulceration and amputation in patients with diabetes, but there is less information on the role of such an approach in patients receiving dialysis treatment.

← Objective

The purpose of the present study was to determine whether the institution of a chiropody program would result in fewer amputations in diabetic patients on peritoneal dialysis (PD).

← Design

Retrospective chart review.

← Setting

The PD program at a tertiary-care hospital.

← Patients

Patients with diabetes that were enrolled in the PD program between January 1997 and December 1999, inclusive, that were offered the opportunity to see a chiropodist, and that agreed to be seen. A total of 132 patients were included.

← Intervention

Education about foot care, assessment, and, in some instances, treatment by a chiropodist.

← Results

Patients with an amputation were more likely to be male ( p < 0.01) and have peripheral vascular disease ( p < 0.001) compared to those without an amputation. They also had a lower average mean arterial pressure ( p < 0.05), lower weekly creatinine clearance ( p < 0.01), higher mean erythropoietin dose ( p < 0.05), and longer duration of end-stage renal disease ( p < 0.001). Factors that were predictive of shorter time to death or amputation were older age [hazard ratio (HR) = 1.03, p < 0.05], peripheral vascular disease (HR = 2.66, p < 0.01), and cerebrovascular disease (HR = 2.70, p < 0.01). Being seen by a chiropodist was protective (HR = 0.39, p < 0.01).

← Conclusion

The current study suggests that a chiropody program may help to prevent amputation in patients with diabetes on PD.

The Role of Na, K-Atpase Inhibitors in Hypertension and End-Stage Renal Disease

Objective

To review the role of Na, K-ATPase inhibitors in the pathogenesis of essential hypertension and hypertension associated with end-stage renal disease.

Data Sources

MEDLINE search, 1966 to 1997.

Results

There is a suggestive physiologic and epidemiologic relationship between Na, K-ATPase inhibition and hypertension. However, clearance data cannot support the hypothesis that differential metabolism of this family of compounds explains the improved hypertensive control seen in patients on peritoneal dialysis compared to those on hemodialysis.

Conclusions

As a result of the complex methodologies involved, it is unclear whether Na, K-ATPase inhibitors playa significant role in the hypertension of endstage renal disease in general and peritoneal dialysis in particular.

Recurrence of Hyperparathyroidism after Total Parathyroidectomy and Autotransplantation in Peritoneal Dialysis Patients

Objective

To evaluate the effectiveness of total parathyroidectomy (PTX) with autotransplantation in the treatment of secondary hyperparathyroidism (HPT), and to assess recurrence rate of HPT in this peritoneal dialysis (PD) population.

Design

A retrospective study in a single home PD unit.

Patients

Between 1994 and 1998, 19 of 574 patients on PD underwent PTX for treatment of secondary HPT.

Main Outcome Measures

Clinical and biochemical improvement, recurrence of HPT, improvement in anemia post-PTX.

Results

Nineteen (3.3%) patients required PTX between 1994 and 1998. These 5 men and 14 women ranged in age from 22 to 66 years; they had been on maintenance PD pre-PTX for 47.5 ± 38.1 months, and were followed for 26.1 ± 15.5 months post-PTX. Sixteen patients had temporary hypocalcemia that was managed by oral (n = 10) or intravenous (n = 6) calcium supplements and calcitriol, while 3 patients had severe “hungry bone” syndrome postoperatively. One patient had recurrent laryngeal nerve palsy post-PTX. Bone pain disappeared in all 12 patients. Pruritus improved in 12/13 patients; fatigue improved in 15/16 patients. Comparison showed significant differences between hemoglobin and hematocrit values 1 month pre-PTX and 12 months post-PTX ( p < 0.05). Parathyroid hormone (PTH) level in 15 (79%) patients returned to normal (≤€7.6 pmol/L) during the first month post-PTX. In 5/12 (42%) patients, PTH level was ≤ 7.6 pmol/L 2 years post-PTX, while in 2/12 (17%), PTH was > 22.8 pmol/L (three times normal) 2 years post-PTX, and 3/5 (60%) patients had a PTH > 22.8 pmol/L 3 years post-PTX.

Conclusions

Total PTX with autotransplantation is associated with a tendency for recurrence of HPT. Our findings suggest that total PTX with autotransplantation may be an ineffective procedure in controlling HPT over the long term.

The Pharmacokinetics of Intraperitoneal Erythropoietin Administered Undiluted Or Diluted in Dialysate

+ Objective

To compare the bioavailability of intraperitoneal erythropoietin (EPO) administered undiluted versus diluted in 2 L of dialysis fluid.

+ Design

Group 1 patients received one dose of EPO, 400 Ulkg BW given with vehicle only. This dwelled for 8 hours after which 2 L of dialysate were infused. Group 2 patients received the same dose of EPO diluted in 2 L of dialysate which dwelled for 8 hours. Both groups resumed their CAPD regimen after the first 8 hours. Blood levels of EPO were measured for 24 hours in both groups.

+Setting

The Home Peritoneal Dialysis Unit, Toronto Hospital, Western Division.

+ Patients

The participants were on CAPD for at least three months, free of peritonitis, and had no abnormalities of peritoneal transport. Three patients took part in both arms of the study, and there were 6 patients altogether in each group.

+ Results

When EPO was administered undiluted, there was a greater than ninefold increase in bioavailability of the hormone as measured by the area under the curve (AUC), compared to when the same dose was diluted in 2 L of dialysis fluid.

+ Conclusions

The previous studies that reported low bioavailability of intraperitoneal EPO used the hormone diluted in dialysate. The current findings suggest that if EPO is given in the dry peritoneal cavity, the bioavailability is greatly improved and may be clinically effective. Intraperitoneal instillation may prove to be an alternative route for EPO in the peritoneal dialysis patient unable or unwilling to receive subcutaneous injections. We are currently studying the effectiveness of undiluted intraperitoneal EPO in CAPD patients.

Emergence of Mupirocin-ResistantStaphylococcus Aureusin Chronic Peritoneal Dialysis Patients using Mupirocin Prophylaxis to Prevent Exit-Site Infection

Objective

To determine the prevalence of the carriage of Staphylococcus aureus (SA), methicillin-resistant Staphylococcus aureus (MRSA), and mupirocin-resistant Staphylococcus aureus (MuRSA) in chronic peritoneal dialysis (CPD) patients after 4 years of prophylactic mupirocin application to the exit site, in a peritoneal dialysis unit.

Methods

Three swabs were collected from the nares, axillae/groin, and exit site, respectively, from 149 patients on CPD between May and July 2001. All swabs were cultured on solid selective agar (mannitol salt agar) and in mannitol salt broth. Staphylococcus aureus isolates were tested for methicillin resistance using oxacillin screening plates, and mupirocin resistance using E-test strips. Low-level MuRSA was defined as minimum inhibitory concentration (MIC) of 4 mg/mL or more, and high-level MuRSA as MIC of 256 mg/mL or more.

Results

Staphylococcus aureus was isolated from 26 (17%) patients (25 from nares/axilla/groin, and 1 from the exit site). High-level MuRSA was isolated from 4 patients (3% of the total study population; 15% of total SA isolates). No MRSA was detected. One patient with high-level MuRSA had peritonitis due to SA, resulting in treatment failure and catheter loss, soon after the swabs were collected for the study.

Conclusion

We report the emergence of high-level MuRSA in CPD patients after a 4-year practice of continuous use of mupirocin in a small number of patients in our unit. Our results may have significant implications for the future practice of prophylactic use of mupirocin by CPD patients to prevent exit-site infection.

Late Renal Transplant Failure: An Adverse Prognostic Factor at Initiation of Peritoneal Dialysis

Background

Early renal transplant failure necessitating a return to dialysis has been shown to be a poor prognostic factor for survival. Little is known about the outcome of patients with late transplant failure returning to dialysis. It was our clinical impression that late transplant failure (>2 months) carries an increased morbidity and mortality risk in patients returning to dialysis.

Objective

To determine whether patients with a failed renal transplant have an outcome different to those on dialysis who have never received a kidney transplant.

Setting

Peritoneal dialysis (PD) unit in a teaching hospital.

Patients and Design

All failed renal transplant patients (fTx) in the Toronto Hospital Peritoneal Dialysis program between 1989 and 1996 were identified. This cohort of 42 fTx patients was compared with a cohort of randomly selected never-transplanted PD patients (non-Tx). The PD program was selected because of the availability of well-documented patient archival material. The non-Tx group was matched for age and presence of diabetes. Data were collected until retransplantation, change of dialysis modality or center, death, or until June 1998.

Results

There was no difference at initiation of PD between groups in serum albumin, residual renal function, or mean serum parathyroid hormone level. The mean low-density lipoprotein level was significantly higher in the fTx cohort. The duration of dialysis before Tx in fTx patients accounted for the increased total length of dialysis in fTx (mean 15 months). However, post-Tx the duration of PD was similar for both groups (30.7 months for fTx vs 31.6 months for non-Tx). The fTx group had a considerably worse outcome than the non-Tx group. The time to first peritonitis, subsequent episodes of peritonitis, catheter change, or transfer to hemodialysis occurred at a much faster rate in fTx patients. The most dramatic difference was in survival. There were 3 deaths in the non-Tx group and 12 in the fTx group ( p < 0.01). The mean age at time of death in the fTx group was 47.5 years. Deaths were due mainly to gram-negative peritonitis and cardiovascular disease.

Conclusions

W e conclude that late failed renal transplant patients starting dialysis are at increased risk of complications and have strikingly higher mortality rates than non-Tx patients. A previously failed kidney transplant can be considered an adverse prognostic factor for patients commencing PD; these patients need to be closely monitored. Although this study was limited to PD patients, the same principles likely apply to fTx patients returning to any form of renal replacement therapy.

Predictors of Outcome following Bacterial Peritonitis in Peritoneal Dialysis

Objective

No studies have been done to examine factors that predict the outcome of bacterial peritonitis during peritoneal dialysis (PD), beyond the contribution of the organism causing the peritonitis, concurrent exit-site or tunnel infection, and abdominal catastrophes.

Design

In this study we examined several clinical and laboratory parameters that might predict the outcome of an episode of bacterial peritonitis. Between March 1995 and July 2000, we identified 399 episodes of bacterial peritonitis in 191 patients on dialysis.

Results

There were 260 episodes of gram-positive peritonitis, 99 episodes of gram-negative peritonitis, and 40 episodes of polymicrobial peritonitis. Gram-positive peritonitis had a significantly higher resolution rate than either polymicrobial peritonitis or gram-negative peritonitis. Staphylococcus aureus episodes had poorer resolution than other gram-positive infections. Nonpseudomonal peritonitis had a better outcome than Pseudomonas aeruginosa episodes. Among all the gram-negative infections, Serratia marcescens had the worst outcome. Episodes associated with a purulent exit site had poor outcome only on univariate analysis. For those peritonitis episodes in which the PD fluid cell count was > 100/μL for more than 5 days, the nonresolution rate was 45.6%, compared to a 4.2% nonresolution rate when the cell count returned to 100/μL or less in less than 5 days. Those patients that had a successful outcome had been on continuous ambulatory PD for a significantly shorter period of time than those patients that had nonresolution. The nonresolution rate for those patients that had been on PD for more than 2.4 years was 24.4%, compared to 16.5% for those that had been on PD for less than 2.4 years ( p = 0.05).

Conclusion

The duration of PD and the number of days the PD effluent cell count remained > 100/μL were the only factors that independently predicted the outcome of an episode of peritonitis. Caucasians seem to have a higher nonresolution (failure) rate compared to Blacks. Other variables, such as the number of peritonitis episodes before the episode in question, vancomycin-based initial empiric treatment, serum albumin level, total lymphocyte count and initial dialysate white blood cell count, age, sex, diabetes, previous renal transplantation, and the use of steroids did not affect the outcome of peritonitis.

Nystatin Prophylaxis: Its Inability to Prevent Fungal Peritonitis in Patients on Continuous Ambulatory Peritoneal Dialysis

Objective

To evaluate the potential effectiveness of nystatin as prophylaxis for fungal peritonitis (FP) in patients on continuous ambulatory peritoneal dialysis (CAPD).

Design

This historically controlled study was designed to investigate the effectiveness of nystatin in the prevention of FP. For this purpose we compared the incidence of FP among 240 (new and prevalent) CAPD patients between January 1996 and November 1996 (period A) with its incidence in 240 new and prevalent CAPD patients in our program between January 1997 and November 1997 (period B) when nystatin prophylaxis was used. There were 2400 patient-months in each period. Nystatin (500000 IU four times per day), was given orally at the beginning of other antibiotic therapy (usually for peritonitis) and continued for 5 days after the end of the antibiotic therapy.

Results

During period A, 133 peritonitis episodes were recorded, and during period B, 99 episodes were recorded. Six episodes of FP were identified in over 2400 patient months of period A, and 12 in over 2400 patient-months of period B. This difference was not statistically significant. Three episodes of antibiotic-related FP were seen in period A, and four in period B. The remaining episodes arose de novo, that is, unrelated to the use of antibiotics. We observed no side effects for nystatin.

Conclusion

In CAPD patients the use of nystatin, a nonabsorbable antifungal agent, as prophylaxis in every instance of peritonitis or other indications for antibiotics, did not lower the incidence of fungal peritonitis.

Rate of Decline of Residual Renal Function in Patients on Continuous Peritoneal Dialysis and Factors Affecting It

Objective

We analyzed residual renal function (RRF) in a large number of new peritoneal dialysis (PD) patients to prospectively define the time course of decline of RRF and to evaluate the risk factors assumed to be associated with faster decline.

Study Design

Single-center, prospective cohort study.

Setting

Home PD unit of a tertiary care University Hospital.

Patients

The study included 242 patients starting continuous PD between January 1994 and December 1997, with a minimum follow-up of 6 months and at least three measurements of RRF.

Measurement

All patients had data on demographic and laboratory variables, episodes of peritonitis and the use of aminoglycoside (AG) antibiotics, temporary hemodialysis, and number of radiocontrast studies. Adequacy of PD was measured from 24-hour urine and dialysate collection and peritoneal equilibration test using standard methodology. Further data on RRF was collected every 3 to 4 months until the patient became anuric (urine volume < 100 mL/day or creatinine clearance < 1.0 mL/min) or until the end of study in December 1998.

Outcome Measure

The slope of the decline of residual glomerular filtration rate (GFR) (an average of renal urea and creatinine clearance) was the main outcome measure. Risk factors associated with faster decline were evaluated by a comparative analysis between patients in the highest and the lowest quartiles of the slopes of GFR, and a multivariate analysis using a stepwise option within linear regression and general linear models.

Results

There was a gradual deterioration of residual GFR with time on PD, with 40% of patients developing anuria at a mean of 20 months after the initiation of PD. On multivariate analysis, use of a larger volume of dialysate ( p = 0.0001), higher rate of peritonitis ( p = 0.0005), higher use of AG ( p = 0.0006), presence of diabetes mellitus ( p = 0.005), larger body mass index (BMI) ( p = 0.01), and no use of antihypertensive medications ( p = 0.04) independently predicted the steep slope of residual GFR. Male gender, higher grades of left ventricular dysfunction, and higher 24-hour proteinuria were associated with faster decline on univariate analysis only.

Conclusion

Faster decline of residual GFR corresponds with male gender, large BMI, presence of diabetes mellitus, higher grades of congestive heart failure, and higher 24-hour proteinuria. Higher rate of peritonitis and use of AG for the treatment of peritonitis is also associated independently with faster decline of residual GFR. Whether the type of PD (CAPD vs CCPD/NIPD) is associated with faster decline of residual GFR remains speculative.

Intraperitoneal Administration of Recombinant Human Erythropoietin in Uremic Animals

Previous protocols of administration of recombinant human erythropoietin to patients with end-stage renal disease have been by the i.v. route. Because this method would be impractical for the continuous ambulatory peritoneal dialysis patient, we designed an i.p. dosing protocol in uremic rabbits to examine whether significant amounts of this hormone could be absorbed from the peritoneal cavity. Our results demonstrate that almost all of the erythropoietin is absorbed (or adsorbed) during a prolonged dwell when administered undiluted by dialysate.

The Effect of Small Solute Clearances on Survival of Anuric Peritoneal Dialysis Patients

Objective

Primarily, to determine whether peritoneal small solute clearance is related to patient and technique survival among anuric peritoneal dialysis [continuous ambulatory (CAPD) and automated peritoneal dialysis (APD)] patients. A secondary goal was to describe the ability to attain Dialysis Outcomes Quality Initiative (DOQI) targets among anuric patients on peritoneal dialysis.

Design

Retrospective cohort study via chart reviews.

Setting

Peritoneal Dialysis Unit of Toronto Hospital (Western Division).

Patients

The study included 122 CAPD and APD patients between January 1992 and September 1997, with 24-hour urine volume less than 100 mL, or renal creatinine clearance (CCr) less than 1 mL/minute. Adequacy data were available for 115 patients.

Outcome Measures

Mortality and technique failure (TF). Regression analysis was used to estimate the mortality and TF rate ratios (RR) for peritoneal Kt/V urea (pKt/V) and pCCr, adjusting for age, gender, diabetes, months of follow-up prior to anuria, albumin, transport status, coronary artery disease, cardiovascular disease, and peripheral vascular disease.

Results

Fifty seven per cent (51/89) of patients on CAPD and 81% (21/26) on APD had a weekly pKt/V ≥ 2 and ≥ 2.2, respectively (DOQI targets); whereas only 35% on CAPD (31/89) and 35% (9/26) on APD had a weekly pCCr ≥ 60 L/1.73 m2 and 66 L/1.73 m2, respectively. Median follow-up times among patients were 16.5 and 19.5 months pre- and postanuria, respectively. Patients with pKt/V ≥ 1.85 experienced a strong decrease in patient mortality (RR = 0.54, p = 0.10); the effect was less pronounced for pCCr ≥ 50 L/1.73 m2 (RR = 0.63, p = 0.25). No relationship was observed between pKt/V or pCCr and TF.

Conclusion

Mortality was noticeably less frequent among patients with a pKt/V ≥ 1.85 compared with those with a Kt/V < 1.85 ( p = 0.10). Given the magnitude of the association, the failure to observe statistical significance relates to the size of the patient cohort. Our results imply that it is, in fact, possible to achieve DOQI targets among anuric patients on peritoneal dialysis.

Is Intraperitoneal Tobramycin Ototoxic in CAPD Patients?

In 40 CAPD patients treated for peritonitis, the authors did a prospective study of ototoxic effects of intraperitoneal tobramycin. They evaluated cochlear function in pure-tone threshold audiograms over a range of frequencies from 250–10, 000 Hz, in the speech-reception threshold test and in the speech-discrimination test. These tests were performed within 48 hours of initiation of tobramycin treatment and within 2 or 3 weeks of the drug's discontinuation. With the aminoglycoside doses used in this study, no statistical difference between the mean baseline and mean follow-up hearing levels was seen in these 40 patients. However, according to the standard criteria of ototoxicity, the hearing in 10 of 40 patients (25%) deteriorated after tobramycin, while it improved in seven patients (17.5%). In the remaining 23 (57.5%), hearing remained stable. With respect to the risk factors for ototoxicity such as advanced age, increased duration of treatment, elevated plasma aminoglycoside levels, concomitant treatment with other ototoxic drugs, pre-existing hearing loss, renal dysfunction and hyperthermia, no statistically significant difference was demonstrated between the patients with deteriorated, stable or improved hearing. The results of this study do not confirm that tobramycin given intraperitoneally to CAPD patients produces auditory toxicity. The hearing deterioration observed in 10 patients may be due to synergistic factors. The improvement observed in 7 patients could not be explained.

Gastric Acid Suppression and the Risk of Enteric Peritonitis in Peritoneal Dialysis Patients

Objective

Peritonitis caused by enteric organisms in peritoneal dialysis (PD) patients is associated with greater morbidity and mortality than peritonitis with non-enteric organisms. One reported risk factor for enteric peritonitis (EP) is gastric acid suppression, with two small studies providing conflicting results. The objective of this study was to determine, using a larger patient population, whether gastric acid suppressants are associated with an increased risk of EP.

Patients and Methods

Using a single-center case-control design, information on episodes of EP occurring between 2003 and 2006 was collected. Control episodes were all non-enteric episodes of peritonitis that occurred during the same time interval. Proton pump inhibitor (PPI) or H2-blocker (H2B) use prior to development of peritonitis was documented.

Results

A total of 228 peritonitis episodes among 137 patients met inclusion criteria. In 32% of episodes, the causative organism was enteric. Gastric acid suppressant use was documented in 46% of episodes, with the majority on PPIs. Overall, gastric acid suppression was not associated with a higher EP risk ( p = 0.17). In a post hoc analysis, PPIs were not associated with EP [odds ratio (OR) 1.3, 95% confidence interval (CI) 0.7 – 2.4; p = 0.42], whereas H2Bs were associated with a higher risk of EP (OR 2.9, 95% CI 1.1 – 7.7; p = 0.04), although the number of patients on H2Bs was small.

Conclusion

Overall, gastric acid suppression was not associated with an increased risk of peritonitis with enteric organisms. While PPI use appears to be safe for PD patients with appropriate indications, the potential risk of EP with H2Bs requires further investigation.

Comparison between Bicarbonate/Lactate and Standard Lactate Dialysis Solution in Peritoneal Transport and Ultrafiltration: A Prospective, Crossover Single-Dwell Study

Objective

It has been proposed that biocompatible bicarbonate/lactate based (Bic/Lac), physiologic-pH peritoneal dialysis (PD) solutions will be beneficial in long-term PD. However, we do not yet have detailed knowledge concerning the comparative physiology of buffer transport for these new solutions and their impact on underlying peritoneal transport of solutes and ultrafiltration (UF). The purpose of this study was to investigate the profile of buffer handling and peritoneal membrane transport characteristics during a single dwell of the new Bic/Lac-based versus standard lactate-based (Lac) PD solution.

Methods

In this prospective crossover study, we compared a 25 mmol/L bicarbonate/15 mmol/L lactate buffered, physiologic pH, low glucose degradation product (GDP) solution (Physioneal; Baxter Healthcare, McGaw Park, Illinois, USA) with a standard lactate buffered, acidic pH, conventional solution (Dianeal; Baxter). 18 patients underwent two peritoneal equilibration tests (PETs) with 2.5% Dianeal and 2.5% Physioneal separated by 1 week. Buffer transport, mass transfer area coefficients (MTACs), solute transport, and UF were determined for the two PETs. All bags were weighed by a nurse before instillation and after drainage to assess the net UF in each dwell.

Results

18 patients that met the inclusion criteria were enrolled in this study. Whereas intraperitoneal pH remained constant at 7.52 ± 0.11 throughout the dwell with the Bic/Lac solution, pH was still in the acidic range with the Lac solution after 1 hour (7.29 ± 0.13, p < 0.001); this difference disappeared after the second hour of dwell. The MTACs for creatinine (10.68 ± 3.66 vs 10.73 ± 2.96 mL/minute/ 1.73 m2, p > 0.05) and urea (27.94 ± 10.50 vs 27.62 ± 6.95 mL/min/1.73 m2, p > 0.05), for Bic/Lac versus Lac respectively, did not differ between these two solutions; transport of glucose and other solutes was also similar. However, after a 4-hour dwell with Bic/Lac solution, net UF was significantly lower than that observed with Lac solution (274.2 ± 223.3 mL vs 366.1 ± 217.3 mL, p = 0.026).

Conclusions

Compared to standard Lac-based solution, Bic/Lac based, pH neutral, low-GDP solution avoids intra-peritoneal acidity. Peritoneal mass transport kinetics are similar for small solutes. Net UF is significantly lower with Bic/Lac solution; the mechanism for this is unclear.

Perioperative Management of Peritoneal Dialysis Patients Undergoing Hernia Surgery without the use of Interim Hemodialysis

Objective

To review the feasibility of undertaking elective hernia repair in peritoneal dialysis (PD) patients without converting them to hemodialysis.

Design

A 10-year retrospective review of prospectively collected data.

Setting

PD unit of a university-based hospital.

Patients and Methods

All patients received regular exchanges until the morning of the surgery and remained off dialysis for the first 48 hours postoperatively. After that, PD was gradually reintroduced. The patients on continuous ambulatory PD (CAPD) received intermittent PD (IPD) 3 times per week for 10 hours per day for 2 weeks, followed by 5 exchanges of low volume (1 – 1.5 L) CAPD for 2 weeks, returning to the pre-surgery prescription by 4 weeks. Patients on continuous cycling PD (CCPD) received 1 week of IPD followed by 4 weeks of nocturnal IPD and returned to the original dose in 5 weeks. Between 1 April 1995 and 31 March 2005, 50 consecutive patients were managed by this protocol. Average age was 65 years and 67.7% were males. The original disease was diabetes mellitus (19 patients), hypertension ( 6 ), chronic glomerulonephritis (13), polycystic kidney disease ( 6 ), and others ( 6 ). The types of abdominal hernias included umbilical (25 patients), inguinal (18), incisional ( 5 ), and epigastric ( 2 ). 42 patients were on CAPD and 8 on CCPD. Average duration of PD prior to development of hernia was 16.4 months.

Results

Average pre-surgery creatinine was 673 μmol/L, increasing to 968 μmol/L on IPD. Serum potassium increased from 3.4 to 4.7 mmol/L. No episodes of hyperkalemia were noted. The average total follow-up was 33.4 months. None of the patients had leakage or early hernia recurrence due to early resumption of PD; 13 patients had recurrence of the same hernia after a median 19.9 months; 4 patients had hernias at different sites after an average of 55 months.

Conclusions

Based on this experience, we recommend that PD patients undergoing elective abdominal hernia surgery should continue PD according to the prescribed protocol. Interim hemodialytic support does not appear to be necessary in most patients.

High Peritoneal Permeability is Not Associated with Higher Mortality or Technique Failure in Patients on Automated Peritoneal Dialysis

Background

Patients on continuous ambulatory peritoneal dialysis (CAPD) who have high small-molecule peritoneal transport have increased mortality.

Objective

To investigate the impact of baseline peritoneal transport characteristics on patient and technique survival in incident peritoneal dialysis (PD) patients, most of whom are on automated PD (APD), with the use of icodextrin.

Design

Retrospective observational cohort study.

Setting

A single PD unit.

Patients and Methods

193 new patients that began PD between January 2000 and September 2004, and had an initial peritoneal equilibration test within 6 months of commencement of PD. Patients were divided into low (L), low average (LA), high average (HA), and high (H) peritoneal transport groups. Death-censored technique failure and patient survival were examined.

Results

Of the 193 patients, 151 (78.1%) were on APD or on APD with icodextrin or on CAPD with icodextrin. At the end of 1, 3, and 5 years, patient survival was 91%, 82%, and 67% in LA group; 95%, 77%, and 69% in HA group; and 96%, 71%, and 71% in H group. Technique survival was 100%, 90%, and 77% in LA group; 96%, 84%, and 72% in HA group; and 92%, 87%, and 77% in H group. High peritoneal permeability did not predict worse patient survival or technique failure, while age, diabetes, a lower glomerular filtration rate, and high body mass index (≥ 30 kg/m2) were independent predictors of death.

Conclusion

This study suggests that higher peritoneal transport is not a significant independent risk factor for either mortality or death-censored technique failure. The favorable outcome for high transporters in this study may be due to improved management of volume status by the increased use of APD and the use of icodextrin-based dialysis fluid.

Discordant PD Catheter and Effluent Culture Results. The Limited Clinical Relevance of Culturing PD Catheters

Objectives

To determine if discordance in culture results between the effluent and the tip of the peritoneal catheter had an effect on outcome in patients whose peritoneal dialysis (PD) catheter was removed mostly for nonresolving peritonitis. Reasons for and outcomes of PD catheter removal were also analyzed.

Methods

We retrospectively reviewed the charts of all PD patients with recent peritonitis for which the PD catheter was removed between 1 January 2003 and 30 April 2009. Data including basic demographics, the organism isolated from effluent and from the PD catheter, reason for catheter removal, duration of hospitalization, and development of intra-abdominal collection were extracted as well as mortality within 8 weeks post removal and return to PD after catheter removal.

Results

Fungal peritonitis was the most common reason for PD catheter removal. 20% of the patients developed an intra-abdominal collection. Mortality related to PD catheter removal was low (3/53; 5.6%). The patients ( n =53) were divided into 3 groups: group 1 ( n = 20) had the same culture result of effluent and catheter tip; group 2 ( n = 19) had a negative culture of the catheter tip; and group 3 ( n = 14) had different organism(s) growing from effluent and catheter tip. We found no remarkable differences in duration of PD, catheter age, peritonitis rate, or mortality. Patients in group 1 had significantly more fungal peritonitis than the other 2 groups. In only 4 of the 53 patients (7.5%), the anti-infectious management was changed according to the catheter culture result.

Conclusions

Discordant results between catheter tip culture and effluent culture did not have a significant impact on patient outcome. Sending PD catheters for culture has limited clinical importance.

Predictors of Care Gaps in Home Dialysis: The Home Dialysis Virtual Ward Study

BACKGROUND

Home dialysis patients may be at an increased risk of adverse events after transitional states. The home dialysis virtual ward (HDVW) trial was conducted in Canadian dialysis centers and aimed to evaluate potential care gaps and patient satisfaction during the HDVW.

METHODS

The HDVW was a multicenter single-arm trial including peritoneal dialysis and home hemodialysis patients after 4 different events (hospital discharge, medical procedure, antibiotics, completion of training). Telephone-led interviews using a standardized assessment tool were performed over a 2-week period to assess a patient's care and adjust treatment as required. Upon completion, patients were surveyed to evaluate their perceived impact on domains of care using a rating scale; 1 not satisfied to 10 completely satisfied.

RESULTS

The HDVW trial included 193 patients with a median number of potential care gaps/interventions of 1 (0-2) per patient. Patients admitted to the HDVW after hospital discharge were at a higher risk of potential gaps in care (OR 2.16, 95% CI 1.29-3.62), while longer dialysis vintage was -associated with a lower number of gaps/interventions (OR 0.97 per year, 95% CI 0.95-0.98). A total of 105/193 (54%) patients completed satisfaction surveys. Patients were highly satisfied with the HDVW (median rating scale score 8, IQR 2) and felt it had a positive impact (rating scale score ≥7) on their overall health, understanding of treatment and access to a nephrologist.

CONCLUSION

The HDVW was effective at identifying several potential care gaps, and patients were satisfied across several domains of care. This intervention may be valuable in supporting home dialysis patients during care transitions.

Defining the role of peritoneal dialysis in management of congestive heart failure

Introduction: Congestion is an integral component of heart failure (HF) pathophysiology and portends an adverse impact on outcome. Peritoneal dialysis (PD) is a home-based therapeutic modality that has been used in the setting of refractory congestive HF to help optimize volume status. Not only does PD allow for customized sodium and water removal, but it also provides the opportunity for the patients to fully benefit from guideline-directed medical therapy for HF that could have otherwise been challenging to use. Areas covered: Authors provide an overview of the pathophysiologic basis for the use of PD in HF, followed by a review of the findings of the main clinical trials such as the salutary impact on HF re-admissions and quality of life. Since the goals of therapy in this setting differ from those for patients with end-stage renal disease, pertinent practical considerations in the use of this modality are then discussed as well as potential barriers. Expert opinion: For patients with chronic refractory HF, PD represents an alternative to medical therapy alone. Identification of patients that would benefit most from this modality and detection of major enablers and obstacles for the implementation of this therapy should be the focus of future studies.