Frederic O. Finkelstein

Changes in Quality of Life during Hemodialysis and Peritoneal Dialysis Treatment: Generic and Disease Specific Measures

Despite more than 20 yr of use, relative differences in health-related quality of life (HRQOL) between hemodialysis (HD) and peritoneal dialysis (PD) are not clearly known. The objective of this study was to compare self-reported HRQOL and overall health status for HD and PD patients at the initiation of dialysis therapy and 1 yr later. A prospective cohort of incident ESRD patients was enrolled between October 1995 and June 1998 at 81 outpatient dialysis units in 19 states and included 698 HD and 230 PD patients who completed a baseline CHOICE Health Experience Questionnaire. The main outcome measured was change in qualify-of-life scores from start of dialysis to 1 yr on dialysis and overall health status. Of 928 patients who completed the baseline questionnaire, 585 also completed the 12-mo questionnaire; 101 had died, 55 had received a kidney transplant, and 88 had moved to a new dialysis clinic. PD patients were slightly younger, were more likely to be white, were well-educated, were employed, were married, had less comorbidity, and had higher hematocrit. Unadjusted baseline scores showed better HRQOL for PD patients in both generic and ESRD domains (bodily pain, travel, diet restrictions, and dialysis access [P < 0.05]). At 1 yr, SF-36 scores improved, whereas some ESRD domains improved and others deteriorated. HD patients had greater improvements in two SF-36 domains (physical functioning and general health perception) than PD patients, but results were mixed for ESRD domains (PD is better for finances, HD is better for sleep and overall quality of life). HD and PD patients did not differ in change in overall health status. HD and PD are associated with similar HRQOL outcomes at 1 yr. Generic HRQOL in two domains improved more for HD patients. However, for ESRD-specific HRQOL, results were not consistent; some domains were better for PD patients whereas others were better for HD patients. In advising patients about modality choices, trade-offs should be discussed and individual preferences for specific aspects of HRQOL should be elicited.

Fungal peritonitis in a large chronic peritoneal dialysis population: a report of 55 episodes

Fungal peritonitis (FP) is a rare but serious complication of chronic peritoneal dialysis (CPD) therapy and is associated with high morbidity and CPD drop-out. Risk factors and management of FP remain controversial. We reviewed our experience with FP in an attempt to identify risk factors and to examine outcome in relation to treatment strategies. Between March 1984 and August 1994, 704 patients were maintained on CPD therapy in our unit. A total of 1,712 episodes of peritonitis were identified among these patients. Fungal peritonitis accounted for 55 (3.2%) of these episodes. The patients on CPD therapy who developed FP were similar to those who did not develop FP with regard to age, gender, underlying etiology for end-stage renal disease, and comorbid disease. Prior antibiotic use was noted in 87.3% of episodes of FP. The peritonitis rate in the patients who developed FP was one episode every 5.1 months compared with one episode every 9.9 patient-months in the CPD patients who did not develop this infection. Candida sp caused 74.5% of the episodes of FP. All patients were treated with antifungal drugs. In 85.5% of infections the Tenckhoff catheter was removed within 1 week of the diagnosis of FP; 31.9% of the patients who had the Tenckhoff catheter removed did not have the catheter replaced because of death or transfer to hemodialysis. In the patients who developed FP, 68.1% had the Tenckhoff catheter replaced; of these patients, 90.6% and 59.4% were on CPD therapy 1 and 6 months after catheter replacement, respectively. We conclude that risk factors identified in our population include peritonitis rate and prior antibiotic use. Fungal peritonitis is rare in our CPD population, and although it leads to significant CPD drop-out, it can be managed in many patients with antifungal therapy, early catheter removal, and temporary hemodialysis. Of the catheters replaced between 2 and 8 weeks after the diagnosis of FP, 91% functioned successfully, allowing continuation of CPD.

Differing outcomes of gram-positive and gram-negative peritonitis

Peritonitis remains the leading cause of patient dropout from continuous peritoneal dialysis (CPD) therapy. Few studies have compared patient morbidity, mortality, and outcome for patients undergoing CPD who develop gram-positive and gram-negative peritonitis. We retrospectively reviewed the charts of patients who developed either gram-positive or gram-negative peritonitis between January 1, 1993, and December 31, 1995. Three hundred seventy-five patients who developed 415 episodes of gram-positive and gram-negative peritonitis were maintained on CPD therapy during this time period. There was no difference in age, race, and sex between patients who developed gram-positive or gram-negative peritonitis. More patients with diabetes developed gram-negative peritonitis than gram-positive peritonitis (53% v 40%, respectively; P < 0.05). Coagulase-negative staphylococcal species accounted for 47% of all gram-positive episodes, whereas Klebsiella organisms, Escherichia coli, and Enterobacter organisms accounted for 63% of all gram-negative episodes. Significantly more patients who developed gram-positive peritonitis continued CPD therapy 2 weeks and 6 months after the onset of peritonitis than patients who developed gram-negative peritonitis (97% v 73%; P < 0.05 at 2 weeks and 81% v 58% at 6 months; P < 0.05, respectively). Nine percent of the patients who developed gram-positive peritonitis died within 6 months after the onset of peritonitis, whereas 21% of the patients who developed gram-negative peritonitis died (P < 0.05). Patients who developed gram-negative peritonitis were significantly more likely to require hospitalization than patients who developed gram-positive peritonitis (74% v 24%; P < 0.001). More patients with gram-negative peritonitis required peritoneal catheter removal than patients with gram-positive peritonitis (18% v 4%; P < 0.001). Thirty-two percent of the patients who developed gram-positive peritonitis re-developed an episode of peritonitis with the same organism compared with only 9% of the patients who developed gram-negative peritonitis. Furthermore, peritonitis recurrence with the same organism within 6 months after the initial episode was noted in 60% of the patients with peritonitis caused by Staphylococcus aureus compared with 24% of patients with peritonitis caused by other gram-positive organisms (P < 0.05). We conclude that the outcomes of gram-positive and gram-negative peritonitis are different. When rates of peritonitis are used to predict outcome, it appears that gram-positive and gram-negative peritonitis rates need to be examined separately.

Health-related Quality of Life in CKD Patients: Correlates and Evolution over Time

BACKGROUND AND OBJECTIVES Very few large-scale studies have investigated the determinants of health-related quality of life (HRQOL) in chronic kidney disease (CKD) patients not on dialysis or the evolution of HRQOL over time. DESIGN AND SETTING A prospective evaluation was undertaken of HRQOL in a cohort of 1186 CKD patients cared for in nephrology clinics in North America. Baseline and follow-up HRQOL were evaluated using the validated Kidney Disease Quality Of Life instrument. RESULTS Baseline measures of HRQOL were reduced in CKD patients in proportion to the severity grade of CKD. Physical functioning score declined progressively with more advanced stages of CKD and so did the score for role-physical. Female gender and the presence of diabetes and a history of cardiovascular co-morbidities were also associated with reduced HRQOL (physical composite score: male: 41.0 +/- 10.2; female: 37.7 +/- 10.8; P < 0.0001; diabetic: 37.3 +/- 10.6; nondiabetic: 41.6 +/- 10.2; P < 0.0001; history of congestive heart failure, yes: 35.4 +/- 9.7; no: 40.3 +/- 10.6; P < 0.0001; history of myocardial infarction, yes: 36.1 +/- 10.0; no: 40.2 +/- 10.6; P < 0.0001). Anemia and beta blocker usage were also associated with lower HRQOL scores. HRQOL measures declined over time in this population. The main correlates of change over time were age, albumin level and co-existent co-morbidities. CONCLUSIONS These observations highlight the profound impact CKD has on HRQOL and suggest potential areas that can be targeted for therapeutic intervention.

Association of Social Support with Outcomes in Incident Dialysis Patients

BACKGROUND AND OBJECTIVES The association of social support with outcomes in ESRD, overall and by peritoneal dialysis (PD) versus hemodialysis (HD), remains understudied. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS In an incident cohort of 949 dialysis patients from 77 US clinics, we examined functional social support scores (scaled 0 to 100 and categorized by tertile) both overall and in emotional, tangible, affectionate, and social interaction subdomains. Outcomes included 1-year patient satisfaction and quality of life (QOL), dialysis modality switching, and hospitalizations and mortality (through December 2004). Associations were examined using overall and modality-stratified multivariable logistic, Poisson, and Cox proportional hazards models. RESULTS We found that mean social support scores in this population were higher in PD versus HD patients (overall 80.5 versus 76.1; P < 0.01). After adjustment, highest versus lowest overall support predicted greater 1-year satisfaction and QOL in all patients (odds ratio 2.47 [95% confidence interval (CI) 1.18 to 5.15] and 2.06 [95% CI 1.31 to 3.22] for recommendation of center and higher mental component summary score, respectively). In addition, patients were less likely to be hospitalized (incidence rate ratio 0.86; 95% CI 0.77 to 0.98). Results were similar with subdomain scores. Modality switching and mortality did not differ by social support in these patients, and associations of social support with outcomes did not generally differ by dialysis modality. CONCLUSIONS Social support is important for both HD and PD patients in terms of greater satisfaction and QOL and fewer hospitalizations. Intervention studies to possibly improve these outcomes are warranted.

A multicenter study of noncompliance with continuous ambulatory peritoneal dialysis exchanges in US and Canadian patients

Recent evidence suggested that noncompliance (NC) with continuous ambulatory peritoneal dialysis (CAPD) exchanges may be more common in US than in Canadian dialysis centers. This issue was investigated using a questionnaire-based method in 656 CAPD patients at 14 centers in the United States and Canada. NC was defined as missing more than one exchange per week or more than two exchanges per month. Patients were ensured of the confidentiality of their individual results. Mean patient age was 56 +/- 16 years, 52% were women, and 39% had diabetes. The overall admitted rate of NC was 13%, with a rate of 18% in the United States and 7% in Canada (P < 0.001). NC was more common in younger patients (P < 0.0001), those without diabetes (P < 0.001), and employed patients (P < 0.05). It was also more common in black and Hispanic than in Asian and white patients (P < 0.001). NC was more common in patients prescribed more than four exchanges daily (P < 0.0001) but was not affected by dwell volume. On multiple regression analysis, the independent predictors of NC, in order of importance, were being prescribed more than four exchanges per day, black race, being employed, younger age, and not having diabetes. Being treated in a US unit did not quite achieve significance as a multivariate independent predictor. These findings suggest that NC is not uncommon in CAPD patients and is more frequent in US than in Canadian patients. However, country of residence is less powerful as a predictor of NC than a variety of other demographic and prescription factors.

Breath ethane in dialysis patients and control subjects.

Oxidant stress may play a role in the accelerated pathology of patients on dialysis, especially in the development of cardiovascular disease, which is a frequent condition in end-stage renal disease (ESRD) patients. Measurement of hydrocarbons can be employed to assess oxidant stress since breath hydrocarbons have been directly traced to in vivo breakdown of lipid hydroperoxides. We undertook to measure ethane, a major breath hydrocarbon, in 15 control subjects, 13 patients on peritoneal dialysis (PD), and 35 patients on hemodialysis (HD). Within the HD group, we separately examined 12 diabetic and 23 nondiabetic patients. Breath samples were collected after patients had breathed purified air for 4 min, and ethane content was measured by GC and expressed as pmoles/kg-body weight-minute (pmol/kg-min). As the data for the hemodialysis patients appeared skewed, nonparametric statistical techniques were employed to analyze these data, which are reported as median and interquartile range (IQR). Ethane levels were similar in 15 control subjects (median, 2.50 pmol [1.38-3.30]/kg-min] and 13 PD patients (median, 2.51 pmol [1.57-3.17]/kg-min). Breath ethane was significantly elevated in a portion (18 of 35 patients, 52%) of the HD patients (median, 6.16 pmol [4.46-8.88]/kg-min) (p <.001 vs. control, Mann-Whitney U test). Two of the diabetic HD patients showed extremely high values of breath ethane. Breath ethane was not altered by a single hemodialysis session, suggesting that long-term metabolic processes contribute to its elevation. Measurement of breath ethane may provide insight into severity of oxidant stress and metabolic disturbances, and provide guidance for optimal therapy and prevention of pathology in patients on long-term hemodialysis.

Association between markers of collagen turnover, arterial stiffness and left ventricular hypertrophy in chronic kidney disease (CKD): the Renal Research Institute (RRI)-CKD Study

BACKGROUND Markers of collagen turnover have not been well studied in the context of cardiovascular disease in patients with chronic kidney disease (CKD). We investigated the associations between serum markers of collagen turnover [N-terminal procollagen type 3 propeptide (PIIINP) and carboxy-terminal telopeptide (C1TP)] and both pulse wave velocity (PWV) and left ventricular mass index (LVMI) in a CKD cohort. METHODS The study included 242 patients (mean age 60 ± 15 years, 53% males, 80% Caucasian, CKD Stages 3-5) from the Renal Research Institute (RRI)-CKD Study. Serum PIIINP and C1TP levels were analyzed by radioimmunoassay. PWV was obtained by applanation tonometry from carotid and femoral pressure wave contours. LVMI was measured by echocardiography. Statistical analyses included Pearsons correlations and multiple linear regression. RESULTS Both PIIINP and C1TP values were significantly higher in more advanced stages of CKD (P < 0.05). A positive correlation was demonstrated between PWV and LVMI (r = 0.25, P = 0.0018), persisting after adjustment for potential confounders (partial r = 0.27, P = 0.0009). PIIINP correlated with PWV (r = 0.16, p = 0.029) and LVMI (r = 0.16, P = 0.0018), while C1TP correlated with LVMI (r = 0.18, P = 0.013) but not with PWV (r = 0.12, P = 0.09). In multivariable analysis adjusting for race, diabetes, estimated glomerular filtration rate (eGFR) and renin-angiotensin-aldosterone system inhibitors, only PWV (β = 0.45, P = 0.0017) but not LVMI (P = 0.09) remained significantly associated with serum PIIINP. CONCLUSIONS Our results demonstrate the association of PIIINP (but not C1TP), a circulating biomarker of collagen synthesis with arterial stiffness (but not with LVMI) in a CKD cohort, independent of eGFR. This suggests that altered collagen turnover may play a role in the pathogenesis of arterial stiffness in CKD.

Patient-specific phosphorus mobilization clearance during nocturnal and short daily hemodialysis.

The kinetics of plasma phosphorus during different hemodialysis (HD) modalities are incompletely understood. We recently demonstrated that a pseudo one‐compartment kinetic model including phosphorus mobilization from various body compartments into extracellular fluids can describe intradialytic and postdialytic rebound kinetics of plasma phosphorus during conventional and short 2‐hour HD treatments. In this model, individual patient differences in phosphorus kinetics were characterized by a single parameter, the phosphorus mobilization clearance (KM). In this report we determined KM in patients treated by in‐center nocturnal HD (ICNHD) and short daily HD (SDHD) with low dialyzer phosphate clearance. In the ICNHD study, eight patients underwent 8‐hour HD treatments where intradialytic and postdialytic plasma samples were collected; KM values were determined by nonlinear regression of plasma concentration as a function of time. In the SDHD study, five patients were studied during 28 treatments for approximately 3 hours. Here, KM was calculated using only predialytic and postdialytic plasma phosphorus concentrations. Dialyzer phosphate clearances were 134 ± 20 (mean ± SD) and 95 ± 16 mL/min during ICNHD and SDHD, respectively. KM values for the respective therapies were 124 ± 83 and 103 ± 33 mL/min, comparable to those determined previously during conventional and short HD treatments of 98 ± 44 mL/min. When results from ICNHD, SDHD, and previous HD modalities were combined, KM was directly correlated with postdialytic body weight (r = 0.38, P = 0.025) and inversely correlated with predialytic phosphorus concentration (r = −0.47, P = 0.005). These findings suggest that phosphorus kinetics during various HD modalities can be described by a pseudo one‐compartment model.

Length of time on peritoneal dialysis and encapsulating peritoneal sclerosis : position paper for ISPD : 2017 update

Imperial College Renal and Transplant Centre,1 Hammersmith Hospital, London, UK; University Health Network and the University of Toronto,2 Toronto, ON, Canada; Renal Division,3 Ghent University Hospital, Ghent, Belgium; Kidney Research Center,4 Department of Nephrology, Chang Gung Memorial Hospital, Taoyuan, Taiwan; Yale School of Medicine,5 New Haven, CT, USA; Central Manchester and Manchester Children’s NHS Foundation Trust,6 Manchester, UK; Department of Nephrology,7 University of Queensland at Princess Alexandra Hospital, Brisbane, Australia; Tsuchiya General Hospital,8 Faculty of Medicine, Hiroshima University, Japan; Institute for Applied Clinical Sciences,9 Keele University, Stoke-on-Trent, UK; Pontificia Universidade Catolica do Parana,10 Curitiba, Parana, Brazil; Division of Nephrology,11 Cliniques universitaires Saint-Luc, Brussels, Belgium, et Institut de Recherche Expérimentale et Clinique, Université catholique de Louvain, Brussels, Belgium; and St James’s University Hospital,12 Leeds, UK ISPD GUIDELINES/RECOMMENDATIONS