Why are we Not Getting More Patients onto Peritoneal Dialysis? Observations From the United States with Global Implications

Peritoneal dialysis (PD) offers lifestyle advantages over in-center hemodialysis (HD) and is less costly. However, in the United States, less than 12% of end-stage kidney disease (ESKD) patients are maintained on this modality. In this brief review, we discuss some of the factors underlying the low prevalence of PD. These include inadequate patient education, a shortage of sufficiently well-trained medical and nursing personnel, absence of infrastructure to support urgent start PD, and lack of support for assisted PD, among other factors. Understanding and addressing these various issues may help increase the prevalence of PD in the United States and globally.

Burden of Kidney Disease, Health-Related Quality of Life, and Employment Among Patients Receiving Peritoneal Dialysis and In-Center Hemodialysis: Findings From the DOPPS Program

RATIONALE & OBJECTIVE

Individuals faced with decisions regarding kidney replacement therapy options need information on how dialysis treatments might affect daily activities and quality of life, and what factors might influence the evolution over time of the impact of dialysis on daily activities and quality of life.

STUDY DESIGN

Observational cohort study.

SETTING & PARTICIPANTS

7,771 hemodialysis (HD) and peritoneal dialysis (PD) participants from 6 countries participating in the Peritoneal and Dialysis Outcomes and Practice Patterns Studies (PDOPPS/DOPPS).

PREDICTORS

Patient-reported functional status (based on daily living activities), country, demographic and clinical characteristics, and comorbidities.

OUTCOME

Employment status and patient-reported outcomes (PROs) including Kidney Disease Quality of Life (KDQOL) instrument physical and mental component summary scores (PCS, MCS), kidney disease burden score, and depression symptoms (Center for Epidemiologic Studies Depression Scale [CES-D] score > 10).

ANALYTICAL APPROACH

Linear regression (PCS, MCS, kidney disease burden score), logistic regression (depression symptoms), adjusted for predictors plus 12 additional comorbidities.

RESULTS

In both dialysis modalities, patients in Japan had the highest PCS and employment (55% for HD and 68% for PD), whereas those in the United States had the highest MCS score, lowest kidney disease burden, and lowest employment (20% in HD and 42% in PD). After covariate adjustment, the association of age, sex, dialysis vintage, diabetes, and functional status with PROs was similar in both modalities, with women having lower PCS and kidney disease burden scores. Lower functional status (score <11) was strongly associated with lower PCS and MCS scores, a much greater burden of kidney disease, and greater likelihood of depression symptoms (CES-D, >10). The median change in KDQOL-based PROs was negligible over 1 year in participants who completed at least 2 annual questionnaires.

LIMITATIONS

Selection bias due to incomplete survey responses. Generalizability was limited to the dialysis populations of the included countries.

CONCLUSIONS

Variation exists in quality of life, burden of kidney disease, and depression across countries but did not appreciably change over time. Functional status remained one of the strongest predictors of all PROs. Routine assessment of functional status may provide valuable insights for patients and providers in anticipating outcomes and support needs for patients receiving either PD or HD.

Continuous Peritoneal Dialysis-Associated Peritonitis of Nosocomial Origin

Objective

To describe our experience with nosocomial continuous peritoneal dialysis (CPD)-associated peritonitis focusing on the incidence, possible risk factors, spectrum of organisms, and outcome.

Design

Retrospective review of the medical records of our CPD patients admitted to an acute-care hospital between November, 1993 and December, 1994.

Setting

University-associated acute-care hospitals in New Haven, Connecticut.

Patients

One hundred and eighty-eight patients maintained on CPD therapy and admitted to an acute-care hospital.

Results

Nineteen patients (5%) developing nosocomial peritonitis (NP) were identified from the 408 admissions occurring during the study period. Patients developing NP were older than the hospitalized CPD patients not developing NP(65.5± 14.6vs58.4± 14.7years, p<0.05). Comorbid diseases including diabetes, peripheral vascular disease, gastrointestinal disease, cardiovascular disease, and human immunodeficiency virus seropositivity were not more common in the patients developing NP. Patients developing NP were hospitalized significantly longer than the CPD patients not developing NP (39.5 ± 46.5 days vs 12.7 ± 12.4 days, p < 0.001). The mean serum albumin was lower in the NP patients than in the CPD patients not developing NP (2.35 ± 0.52 g/dL vs 3.02 ± 0.60 g/dL, p < 0.001). Antecedent antibiotic use and performance of invasive procedures were noted in 89% and 68% of the patients developing NP, respectively. Staphylococcal species, enterococcal species, and gram-negative organisms accounted for 26%, 21 %, and 53% of the episodes of NP, respectively. Furthermore, two strains of Enterococcus resistant to vancomycin were cultured. Eight patients developing NP expired, 8 patients continued CPD therapy, 2 patients transferred to hemodialysis, and one patient recovered renal function.

Conclusion

We conclude that NP is uncommon. Increased age, increased length of hospital stay, and hypoalbuminemia may predispose patients to the development of NP. Further studies with case controls should help to clarify whether antecedent antibiotics or prior performance of invasive procedures predispose patients to the development of nosocomial peritonitis. The spectrum of organisms accounting for NP is different than the spectrum of organisms causing community-acquired CPD-associated peritonitis. Some of these organisms may be resistant to standard antibiotic therapies. Patients developing NP do poorly, with 42% expiring while being treated for NP.

First-year outcomes of incident peritoneal dialysis patients in the United States

BACKGROUND

Patterns of early outcomes in peritoneal dialysis (PD) are not well studied and dialysis providers need to establish a baseline of key outcomes for continuous quality improvement initiatives.

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS

Incident PD patients from Fresenius Medical Care, North America from January 1 through December 31, 2009.

FACTORS

Case-mix, comorbid illness, and baseline laboratory values.

OUTCOMES

Death, hospitalization, peritonitis, and switch to hemodialysis (HD) within the first year on PD therapy.

MEASUREMENTS

Event rates and outcome predictors.

RESULTS

Of 1,677 incident PD patients, 1,313 started on PD therapy and 367 switched from HD therapy within the first 90 days. Normalized first-year event rates for mortality, switch to HD therapy, peritonitis, and hospitalization were 10, 27, 42, and 128 per 100 patient-years, respectively. 336 of 463 (72.6%) first peritonitis episodes and 637 of 939 (67.8%) first hospitalizations occurred within the first 6 months of PD treatment. Black race, higher body mass index, non-Hispanic ethnicity, peripheral vascular disease, and low weekly Kt/V associated with peritonitis risk. Dialysis vintage, female sex, diabetes, congestive heart failure, peripheral vascular disease, and history of limb amputation along with lower laboratory values for albumin, hemoglobin, and phosphorus and weekly Kt/V associated with hospitalization. Switchers to HD therapy (n=350) used central venous catheters 81.4% of the time as initial access (still 78.3% at 90 days later) because of lack of permanent access.

LIMITATIONS

Residual confounding from unmeasured variables and exclusion of patients with a training day but who never started home PD therapy.

CONCLUSIONS

Despite low first-year mortality, incident PD patients had high morbidity, particularly within the first 3-6 months. Increased focus to identify patients at greatest risk for peritonitis and hospitalization, as well as evaluation of care processes and implementation of preventive strategies, is required. Access planning for transition to HD therapy needs more attention, even during the first PD year.

Prospective safety study of bardoxolone methyl in patients with type 2 diabetes mellitus, end-stage renal disease and peritoneal dialysis

Patients on peritoneal dialysis experience inflammation associated with advanced chronic kidney disease and the therapy itself. An important consequence of the inflammation may be acceleration of the rate of decline in residual renal function. The decline in residual renal function has been associated with an increased mortality for patients in this population. Bardoxolone methyl is a synthetic triterpenoid. To date, the effects of bardoxolone methyl on kidney function in humans have been studied in patients with type 2 diabetes mellitus. A large-scale event-driven study of bardoxolone methyl in patients with type 2 diabetes mellitus with stage 4 chronic kidney disease is underway. The safety of bardoxolone methyl has not been evaluated in patients with more advanced (stage 5) chronic kidney disease or patients on dialysis. This report describes a proposed double blind, prospective evaluation of bardoxolone methyl in patients with type 2 diabetes mellitus receiving peritoneal dialysis. In addition to assessing the safety of bardoxolone methyl in this population, the study will evaluate the effect of bardoxolone methyl on residual renal function over 6 months as compared to placebo.

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.

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.

Catheter-related bacteremia in hemodialysis patients: the role of the central venous catheter in prevention and therapy

Infections are a leading cause of morbidity and mortality in patients with end-stage renal disease. Infections in hemodialysis patients are strongly associated with the use of an indwelling central venous catheter. S. aureus, coagulase-negative staphylococci and Gram-negative rods account for the majority of these infections. The outcome of catheter-related bacteremia depends on appropriate antibiotic therapy and management of the hemodialysis catheter. Most studies note that there is no difference in outcome if the catheter is changed over a guidewire in addition to antibiotic therapy or if the catheter is completely removed and reinserted at a later date. However, bacteremia with certain organisms, particularly S. aureus, is associated with complications. Thus, the data suggests that the catheter needs to be promptly removed in patients developing S. aureus bacteremia.Bacterial biofilm likely has a critical role in the pathogenesis of these infections. Numerous in vitro and in vivo studies have demonstrated both a reduction in infection rate with the use of antibiotic catheter locks as well as a reduction in the production of or eradication of bacterial biofilm. Future studies ought to target, firstly, a reduction in the reliance on central venous catheters; and secondly, the formulation of practical strategies to reduce patient risk for developing catheter-related bacteremia.

Tidal PD: its role in the current practice of peritoneal dialysis

The role of tidal peritoneal dialysis (TPD) has been the subject of several studies over the past 30 years. The use of the newest generation of cyclers combined with the increasing number of chronic peritoneal dialysis (CPD) patients being maintained on cycler therapy has stimulated a reexamination of the role of TPD in the care of CPD patients. Several studies over the past decade have examined solute clearances with TPD in patients. These studies suggest that TPD does not result in an increase in clearances when compared to conventional intermittent peritoneal dialysis (IPD). TPD is now primarily used for comfort in patients who experience pain at the start of inflow and/or at the end of outflow. In TPD, the presence of at least some fluid in the abdomen during the exchanges generally eliminates these episodes of pain. It has recently been suggested that accurate assessment of drain and fill phases during automated PD may be helpful in redefining a role for TPD in CPD patients. If the 'slow' drainage time can be kept to a minimum, then it is possible that the efficiency of PD could be enhanced. Defining the critical volume and then optimizing the TPD regimen could perhaps increase the clearances noted with TPD.

Metabolic lung disease: diffuse metastatic pulmonary calcifications with progression to calciphylaxis in end-stage renal disease

The goal of the present case report is to enhance recognition of the incidence of tissue calcifications, which are quite common in patients with end-stage renal disease. We focus on pulmonary metastatic calcifications and the potential progression of this condition to tissue necrosis and lung cavitations in the setting of severe electrolyte imbalance. This case highlights the importance of early identification of the causes and potential risk factors leading to visceral calciphylaxis.

Structural requirements for a successful chronic peritoneal dialysis program

Recently, there has been a decline in chronic peritoneal dialysis (CPD) utilization in several countries. And, in these countries, the percent of patients with end-sage renal disease maintained on CPD is less than nephrologists think is appropriate. The reasons for these problems are uncertain, but it is likely that difficulties with the structural organization of CPD facilities play a contributory role. This paper discusses the structural requirements for a successful CPD program, focusing attention on the following domains: (1) adequate chronic kidney disease education, (2) provision and support of physician training in the principles and practice of CPD, (3) adequate size and organization of CPD centers, (4) development of appropriate support systems within the CPD facility, and (5) development of appropriate continuous quality improvement programs to monitor a variety of domains, including adequacy of dialysis, peritonitis rates, catheter infections and problems, psychosocial status of patients, etc.

The impact of various cycling regimens on phosphorus removal in chronic peritoneal dialysis patients

BACKGROUND

The National Kidney Foundation Dialysis Outcome Quality Initiative clinical practice guidelines have suggested that serum phosphate levels be maintained at < or =5.5 mg/dL in patients maintained on dialysis. Over 45% of anuric patients maintained on CAPD have serum phosphate levels >5.5 mg/dL. The present study was designed to address the question whether phosphate removal could be enhanced by increasing the dialysate volume during cycler peritoneal dialysis therapy.

METHODS

Medically stable patients maintained on chronic peritoneal dialysis therapy, who were high or high-average transporters and had serum phosphate levels > or =5.5 mg/dL, were invited to participate in the study. The protocol involved measuring phosphate and creatinine clearances at weekly intervals on three different cycler prescriptions consisting of 7 and 12 full cycles or 24 cycles with 50% tidal PD (TPD) over 9 hours. Ten patients agreed to participate. Those patients (n=7) with a BMI > 22 had 2 liter (L) fill volumes and 14 L of total dialysate (7 cycles of 2 L) or 24 L total dialysate (12 cycles of 2 L or 50% TPD with 24 cycles).The patients (n=3) with a BMI < 20 had 1.2 L fill volumes and 8.4 L total dialysate (7 cycles) or 14.4 L total dialysate (12 cycles of 1.2 L or 50% TPD with 24 cycles).

RESULTS

The mean age (+/- SD) of the study patients was 50.8 (+/- 9.3) years. There were 6 females, 6 Caucasians and 4 African-Americans. The mean weight of the patients was 71.5 (+/- 24.2) kg and mean height 1.65 (+ 7.6) meters. The mean BMI was 18.3 (+/- 1.27) in the < 20 BMI group and 30.3 (+/- 6.6) in the > 22 BMI group. The mean phosphate clearance (L/night/1.73m 2 ) increased from 3.96 (+/- 1.16) with 7 cycles to 4.71 (+ 1.81) with 12 cycles and 4.51 (+/- 1.61) with 50% TPD. Creatinine clearance (L/night/1.73m 2 ) was 4.74 (+/- 1.74) with 7 cycles, 6.06 (+/- 2.04) with 12 cycles and 5.61 (+/- 2.01) with TPD.

CONCLUSION

The present study indicates that there is a significant, 19% (P < 0.005) rise in phosphate clearance by increasing dialysate volume 71% from 7 cycles to 14 cycles compared to a 27% increase in creatinine clearance. With tidal PD, phosphate clearance increased by 12% (p=NS) and creatinine clearance increased 18 % (p, 0.02). This increase in phosphate clearance translates into <50 mg net phosphate removal in 9 hours, assuming a serum phosphate of 6 mg/%. Thus, increasing dialysis cycles and volume results in only a minimal increase in net phosphate removal.

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.

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.

Erectile dysfunction in chronic peritoneal dialysis patients: incidence and treatment with sildenafil

OBJECTIVES

Sexual and erectile dysfunction (ED) have been reported to occur frequently in male patients with end-stage renal disease maintained on dialysis. Numerous etiologies for this ED have been suggested. Although a variety of therapies for the ED of the dialysis patient have been suggested, most clinicians indicate that patients report a poor response to therapy. Recently, sildenafil has been reported to be beneficial in treating patients with ED of both organic and psychogenic causes. The present study was designed to document the incidence of ED in male patients maintained on chronic peritoneal dialysis (CPD) and to determine the efficacy of prescribing sildenafil therapy to treat their ED.

METHODS

All male patients in our CPD unit were notified by letter of the availability of sildenafil as a treatment modality for ED. A sexuality/erectile dysfunction assessment was conducted in all male patients by their primary nephrologist. Patients who reported ED and who had no medical contraindication to sildenafil were offered this therapy. Those patients who were interested in this treatment were interviewed by a social worker, and patients were asked to complete the International Index of Erectile Function questionnaire. Sildenafil was prescribed at a starting dose of 25 mg and increased to a maximum of 100 mg during a 12-week study trial. Patients were re-evaluated 6 and 12 weeks after the start of therapy.

RESULTS

There were 68 male patients maintained on CPD at the time of the study. Mean age of all patients was 60.8 +/- 15.3 years and mean duration on PD was 32.6 +/- 25.6 months. Thirty-three patients had diabetes, 66 hypertension, 35 peripheral vascular disease, and 32 coronary artery disease. Thirty-two of 68 male patients in the CPD unit were assessed to have ED. Only 17 of the 32 patients expressed interest in pursuing sildenafil therapy. Two of these patients were excluded because they were receiving nitrate therapy. Of the 15 patients who agreed to take sildenafil, only 6 completed the 12-week study. Two of these patients responded to sildenafil.

CONCLUSION

Erectile dysfunction is common in male patients maintained on CPD. Only about half of patients with ED in the present study were willing to consider sildenafil therapy to treat the ED and, of those who agreed to treatment, only a minority completed the 12-week trial; 2 of these 6 patients reported a satisfactory response.

Identification and treatment of depression in a cohort of patients maintained on chronic peritoneal dialysis

Depression is the most commonly encountered psychological problem in patients with end-stage renal disease (ESRD). Depression has recently been shown to significantly impact on the morbidity and mortality of patients undergoing therapy for ESRD. The present study was designed as a pilot study to evaluate the feasibility of screening a large cohort of patients maintained on chronic peritoneal dialysis (CPD) for depression and then pharmacologically treating those patients assessed to have clinical depression. One hundred thirty-six patients maintained on CPD in our CPD unit were screened for depression using the Beck Depression Inventory (BDI), a self-administered questionnaire. Patients with scores of 11 or greater were referred to a trained psychiatric interviewer for further evaluation to confirm the diagnosis of clinical depression and determine whether the patient was a candidate for antidepressant medication. Sixty-seven patients had BDI scores of 11 or greater, and 60 of these patients were asked to participate in further evaluation and possible therapy. Only 27 patients agreed to further study and were evaluated by a trained psychiatric interviewer for clinical depression. Twenty-three of these patients were assessed to have clinical depression, and 22 patients were eligible for antidepressant medication based on their scores on the Hamilton Depression Scale and psychiatric interview. Eleven patients completed a 12-week course of therapy with antidepressant medication, and their BDI scores decreased from a mean of 17.1 +/- 6.9 (SD) to a mean of 8.6 +/- 3.2. Seven patients were treated with sertraline, 2 patients with bupropion, and 2 patients with nefazodone. It is concluded that (1) depression is commonly present in patients maintained on CPD, (2) the BDI is a useful tool to use to screen for clinical depression, and (3) clinical depression is treatable with medication in this patient population.

Continuous peritoneal dialysis and the extended care facility

The projected disproportionate increase in the number of elderly patients reaching end-stage renal disease constitutes a dramatic change in dialysis demographics. The nursing home or extended care facility (ECF) will become an increasingly important feature of care for both rehabilitation and long-term patient management. For continuous peritoneal dialysis (CPD), the ECF has been critically evaluated in only a single specialized, university-based, geriatric facility that included trained peritoneal dialysis nurses providing care. We have trained multiple ECF personnel in 10 community-based ECFs to provide all CPD-related therapy for 93 patients between November 1993 and December 1998, for a total of 289.3 patient-months. All ECFs have maintained their CPD program. Outcome measures, including hospitalization, mortality, technique failure, and peritonitis rates, show the success and feasibility of using community-based ECFs for CPD. The use of multiple ECFs for CPD appears to offer distinct advantages over solo structured ECF programs without jeopardizing outcomes. A highly structured CPD education program for ECF personnel by nephrology staff is manageable and appears critical for the success of maintaining CPD in the ECF.

Method for studying development of colonization and infection of dialysis catheters

Microbial colonization and infection of dialysis catheters is the major cause of catheter failure. The present study aimed to develop a method to permit the study of microbial biofilm formation and antibiotic prophylaxis and therapy. Standard silicon rubber and silver-impregnated catheters were sectioned into 1 mm slices and placed into 1-cm x 2-cm culture slide chambers. Fresh clinical isolates were obtained from infected patients and suspended in concentrations of 10(3), 10(6), and 10(9) colony forming units (CFU) per milliliter in a variety of liquid suspending culture media, which included serum protein constituents. Antibiotics could be added to the suspending fluid to determine prophylactic activity, or at any time thereafter to determine therapeutic activity. The catheter sections were incubated with the microbial challenge for 6 hours, 12 hours, 24 hours, and 48 hours and then washed in flowing distilled water to remove unattached biofilm. They were then stained with acridine orange, which fluoresces microbial DNA, and were examined by confocal scanning laser microscopy. Biofilm formation, representing colonization and infection, were quantified by comparing the fluorescent pixel analysis of the uninoculated control with the challenged catheter. The method was reproducible and permitted quantitative analysis. Standard silicon rubber catheters demonstrated greater biofilm formation than silver-impregnated catheters. The method examines the factors involved in microbial colonization and infection, and in antibiotic prophylaxis and therapy.

Incidence of peritonitis in chronic peritoneal dialysis patients infused with intravenous iron dextran

BACKGROUND

The Dialysis Outcomes Quality Initiative (DOQI) guidelines, published in 1997, emphasize the need for careful monitoring of iron stores and for provision of adequate iron replacement therapy to achieve target goals of hemoglobin concentration in end-stage renal disease (ESRD) patients, especially those treated with recombinant erythropoietin (rHuEPO). Intravenous iron dextran (IVID) therapy, which has long been used in hemodialysis patients, is increasingly being used in chronic peritoneal dialysis (CPD) patients. In 1997, we began using this form of iron therapy for our CPD patients. However, because considerable data exists to show a relationship between iron metabolism and acute infections, we questioned whether IVID infusion placed our patients at greater risk for peritonitis, the leading cause of death and patient drop-out from CPD therapy.

OBJECTIVE

To evaluate the relationship between iron and infection, we studied episodes of peritonitis in CPD patients who were infused with IVID.

DESIGN

In a retrospective study of adult CPD patients who received IVID during 1998, we investigated the occurrence of peritonitis episodes and the spectrum of causative organisms. Patients with a hemoglobin level of < 12.5 g/dL who also had a ferritin level < 100 ng/mL or a transferrin saturation level < 20% (or both) and who did not respond to oral iron therapy, were administered between 0.5 g and 1.0 g of IVID in an outpatient hospital setting. We calculated the expected and observed number of peritonitis episodes in these patients within 30, 60, and 90 days after infusion of IVID.

RESULTS

During the study period, 56 patients received 77 doses of IVID, with 14 patients requiring 2 or more infusions. Of the 77 doses, 71 were given as a 1-g bolus. The IVID was well tolerated by all patients. Within 90 days of IVID administration, 14 patients developed peritonitis: 6 episodes occurred within 30 days, 7 episodes occurred between 31 and 60 days, and 1 episode occurred between 61 and 90 days after the IVID dosing. The peritonitis rate for patients not receiving IVID was 1 episode per 13.7 patient-months. Taking this rate as the "expected" rate, the expected number of episodes of peritonitis for the study population was 5.6 episodes within 30 days, 11.2 episodes within 60 days, and 16.8 episodes within 90 days following IVID administration. The difference between the expected and observed rates of peritonitis in patients who were dosed with IVID was not statistically different. The spectrum of organisms seen in the peritonitis episodes in the study population was not significantly different from that seen in the peritonitis episodes in our CPD unit population.

CONCLUSIONS

There is evidence that IVID infusion therapy can improve anemia and reduce rHuEPO requirements in CPD patients, usually without adverse reaction and without exposing patients to an increased risk of peritonitis. More research is needed in the area of potential increased risk of infection in ESRD patients who are (1) infused with large doses of IVID, and (2) iron-overloaded.

Revascularization of renal artery stenosis in patients with renal insufficiency

The incidence and prevalence of end-stage renal disease (ESRD), particularly in the elderly population, have continued to increase in the United States. It is estimated that 10% to 20% of the elderly patients with ESRD have potentially remediable renal vascular disease. The purpose of the present study is to examine the results of renal artery revascularization in 20 patients aged older than 55 years with chronic renal failure (serum creatinine level >2 mg/dL) with proximal renal artery stenosis (RAS) diagnosed by magnetic resonance angiography (MRA) who underwent surgical or percutaneous revascularization. Patients were followed up closely in the postrevascularization period; renal function was monitored and potential complications of the procedure were carefully noted. Four of the 20 patients developed serious complications, including 3 patients with clinically significant atheroembolic disease and 1 patient with renal artery dissection. Seven patients developed greater than 5% eosinophilia. Five of the 20 patients had a deterioration in renal function 3 to 6 months after the procedure, and only 5 patients had a reduction in serum creatinine concentration 3 to 6 months after the procedure. The present study suggests that in elderly patients with chronic renal failure and proximal RAS, revascularization of renal vessels is associated with a high complication rate, and improvement in renal function occurs in only 25% of the patients. Whether revascularization can slow the rate of progression of renal failure remains uncertain and can only be answered by a large prospective trial.

Tidal peritoneal dialysis: comparison of different tidal regimens and automated peritoneal dialysis

BACKGROUND

The National Kidney Foundation Dialysis Outcomes Quality Initiative (DOQI) clinical practice guidelines have suggested minimal weekly Kt/V urea and creatinine clearance goals for peritoneal dialysis patients maintained on continuous ambulatory peritoneal dialysis (CAPD) and automated peritoneal dialysis (APD). Achieving these goals may present problems, particularly in larger patients whose residual renal function declines. Thus, modifications of the dialysis regimen, such as tidal peritoneal dialysis (TPD), have been developed. However, the ability of TPD to improve the efficiency of the dialysis procedure remains uncertain.

METHODS

Stable, cycling peritoneal dialysis patients were placed into two groups to study the effectiveness of different TPD prescriptions on peritoneal clearances of urea and creatinine. The volume of dialysis solution used and the duration of therapy were fixed in the two groups. Comparisons were made to conventional APD using multiple hourly cycles in which spent dialysis solution was completely drained with each cycle. Group I patients received a total of 15 L of PD solution over 9.5 hours in the dialysis unit. These patients received 10, 25, and 50% TPD and APD on four separate days. Group II patients received 24 L of PD solution over 9.5 hours. These patients received 25 and 50% APD on separate days in the dialysis unit. Peritoneal dialysis clearances for urea (pKt/V) and creatinine (pCCr) levels were calculated for both groups. The results were then analyzed to determine whether there was any significant difference among the various prescriptions.

RESULTS

The data in the group I patients indicated a mean daily pKt/V of 0.22 +/- 0.03 with 10% TPD, 0.23 +/- 0.02 with 25% TPD, 0.25 +/- 0.02 with 50% TPD, and 0.26 +/- 0.02 with APD. Paired t-test analysis for pKt/V demonstrated that 10 and 25% TPD resulted in significantly lower values than 50% TPD and APD (P < 0.05). Mean daily pCCr L/24 h/1.73 m2 was 6.03 +/- 0.72 for 10% TPD, 6.34 +/- 0.83 for 25% TPD, 6.65 +/- 0.51 for 50% TPD, and 7.01 +/- 0.96 for APD; these differences were not significantly different. The data in the group II patients demonstrated a mean daily pKt/V of 0.28 +/- 0.03 with 25% TPD, 0.29 +/- 0.05 with 50% TPD, and 0.30 +/- 0.05 for APD. The mean daily pCCr was 6.69 +/- 0.47 for 25% TPD, 8.09 +/- 1.30 for 50% TPD, and 7.63 +/- 1.13 for APD. There were no statistical differences for pKt/V and pCCr within the 24 L group.

CONCLUSION

When the duration of therapy and volume of dialysate volume are kept constant, TPD does not result in an improvement in clearances compared with conventional APD, at least with dialysate volumes up to 24 L.

Tidal peritoneal dialysis to achieve comfort in chronic peritoneal dialysis patients

Patients with end-stage renal disease on chronic peritoneal dialysis (CPD) can usually tolerate continuous ambulatory peritoneal dialysis (CAPD) or continuous cycling peritoneal dialysis (CCPD) without abdominal discomfort or pain. In some patients, pain or discomfort occurs with complete drain of the peritoneal dialysis solution or upon initiation of dialysis filling when the peritoneal cavity is empty. We report on the use of tidal peritoneal dialysis (TPD) as a modality to alleviate this pain. Of 136 patients in our CPD unit, 18 (13%) were complaining of pain with complete drain or upon instillation of PD fluid. All were placed on TPD after other causes for abdominal pain were excluded. Six patients were placed on 25% TPD, and 12 patients on 50% TPD. The mean Kt/V of the patients on TPD was 2.46 +/- 0.68. With TPD, all patients had complete relief of abdominal discomfort. Patients who develop abdominal pain with complete drain or fill when the abdominal cavity is empty would benefit from TPD and be able to continue with CPD.

Patient assessment of quality of care in a chronic peritoneal dialysis facility

The percentage of patients with end-stage renal disease (ESRD) maintained on chronic peritoneal dialysis (CPD) in the United States remains well less than the percentage in several other countries. Furthermore, there has recently been a decline in the percentage of patients with ESRD in the United States undergoing CPD. The reasons for this decline are uncertain, and investigators have implicated problems with the kinetics of peritoneal dialysis, peritonitis and exit-site infections, and psychosocial stresses imposed by the therapy. Few studies, however, have considered the role of the dialysis facility itself and patient perceptions of the facility as contributing to problems with the long-term acceptance of CPD. This study is designed to examine patients' perceptions of the organization and structure of the peritoneal dialysis facility and their interactions with the facility, focusing attention on areas of patient satisfaction and dissatisfaction with the facility. The study was conducted in a large, freestanding peritoneal dialysis program in an urban area that currently treats 140 patients undergoing CPD. Thirty patients were randomly selected to participate in the present study. A structured interview that included open-ended questions was administered and tape-recorded by a trained interviewer not affiliated with the dialysis unit. Patient responses were then reviewed by two investigators, and a taxonomy of patient satisfaction and dissatisfaction was developed, using a modification of the classification proposed by Concato and Feinstein. Patient responses were then categorized according to the taxonomy. The most frequently cited areas of patient satisfaction included the amount of information and instruction provided by the staff (n = 30), personal atmosphere of the facility (n = 30), efficiency of delivery of the dialysis supplies (n = 23), and availability of the primary nurse (n = 18). The importance of the nurse-patient interaction was emphasized by all 30 patients, whereas the physician-patient interaction was cited by only 14 patients. The most frequently cited area of dissatisfaction noted by all 30 patients concerned the dialysis regimen itself. The present study focuses attention on patient perceptions of their CPD facility, identifying areas of satisfaction and dissatisfaction. The analysis is important not only in providing a framework for CPD facilities with which to review their own interactions with CPD patients, but also for identifying those areas that require attention to maintain the long-term viability of CPD therapy.

Hyperparathyroidism: a seven-year follow-up

Hyperparathyroidism (HPT) is a common finding in patients with end-stage renal disease (ESRD). Most chronic peritoneal dialysis (CPD) patients with HTP can be successfully managed with phosphate binders, calcium supplements, and calcitriol therapy. Noncompliance with diet, prescribed binder, or calcitriol therapy may also lead to HPT. We reviewed New Haven CAPD unit patients who failed medical therapy and required parathyroidectomy (PTX) for control of severe HPT [sustained immunoreactive parathyroid hormone (iPTH) level > 600 pg/mL]. From 1990 to 1997, 18 out of 620 patients (3.0%) required PTX. Time on dialysis prior to PTX was 44.8 +/- 17.5 (mean +/- SD) months with a range of 13 to 71 months. The mean age was 43.6 +/- 11.8 years with a range of 30 to 66 years. There were 10 females and 8 males. Of the 18 patients, 14 had total parathyroidectomy with arm implants, and 4 had subtotal PTX. Seven of 18 patients had iPTH levels of < 100 pg/mL at 1 year post-PTX (5 patients with arm implants, 2 with subtotal PTX). Three patients required partial arm implant PTX to correct recurrent HPT. Pulse oral calcitriol (POC) was prescribed in 10 patients post PTX to maintain iPTH at target levels. Parathyroidectomy was necessary to correct HPT in 18 of 620 CPD patients from 1990 to 1997. The majority of these patients had excellent results after their PTX. Intact PTH levels of < 100 pg/mL for 1 year or more were noted in 5 of 14 patients with arm implants, and 2 of 4 patients with subtotal PTX. The significance of a persistent iPTH of < 100 pg/mL has yet to be determined in CPD patients.

Peritonitis in the extended-care facility

Many patients with end-stage renal disease (ESRD) require admission to an extended-care facility (ECF). Few data are available concerning the development of peritonitis among continuous peritoneal dialysis (CPD) patients residing in an ECF. We retrospectively reviewed the charts of 77 CPD patients admitted to an ECF between November 1993 and 31 August 1997. A total of 25 episodes of peritonitis developed among CPD patients in the ECF during this period for an overall peritonitis rate of 1 episode in 19.8 patient-months. The CPD patients developing peritonitis in the ECF were similar in age and gender to the CPD patients residing in the ECF not developing peritonitis. There were more African-Americans among the group of CPD patients residing in the ECF who developed peritonitis than among the ECF residents who did not develop peritonitis (41% vs. 23%, respectively; P < 0.05). Patients developing peritonitis in the ECF resided in the ECF significantly longer than the remaining CPD patients not developing peritonitis in the ECF (106 vs. 77 days, respectively; P < 0.05). The overall rate of peritonitis in the ECF was lower than that seen in the community (1 episode in 19.8 patient-months vs. 1 episode in 10.0 patient-months, respectively). The rate of gram-positive peritonitis was lower than the rate of gram-positive peritonitis seen in the community setting (1 episode in 54.9 patient-months vs. 1 episode in 14.9 patient-months, respectively). The rate of culture-negative peritonitis was higher among the ECF patients than among patients developing community-acquired peritonitis (1 episode in 61.9 patient-months vs. 1 episode in 106.2 patient-months, respectively). The spectrum of organisms in the ECF was different than the spectrum noted among patients developing hospital-acquired peritonitis. Eleven of the 25 episodes of peritonitis were treated successfully at the ECF while the remaining 14 episodes of peritonitis were treated at an acute-care hospital. Continuous PD therapy was continued following 19 of the 25 episodes (76%), 1 patient transferred to hemodialysis, and 5 patients expired. We conclude that patients develop peritonitis in the ECF less frequently than in the community setting, with the spectrum of organisms different than the spectrum seen in the community and hospital settings. Seventy-six percent of the patients continue CPD therapy following an episode of peritonitis.

Bilateral renal infarction secondary to paradoxical embolism

Paradoxical embolism is an uncommon but increasingly reported cause of arterial embolic events. Involvement of the kidney is rarely reported. Autopsy studies suggest, however, that embolic renal infarction is underdiagnosed antemortem. We report a case of bilateral, main renal artery occlusion and acute renal failure secondary to paradoxical embolism. Clinical and laboratory data at presentation were not suggestive of renal infarction. Support for the diagnosis of paradoxical embolism, which most commonly occurs across a patent foramen ovale, was made by contrast echocardiography, which provides a sensitive method for detecting right-to-left intracardiac shunts. The often subtle presentation of renal infarction suggests patients with peripheral or central arterial embolic events should be carefully observed for occult renal involvement. Contrast echocardiography should be performed when renal infarction occurs without a clear embolic source to evaluate for paradoxical embolism.

Effect of duration of chronic peritoneal dialysis therapy on the development of peritonitis

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 < or = 12 months; group 2, patients maintained on CPD therapy for 13-36 months; and group 3, patients maintained on CPD therapy for > or = 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.

Value of scintigraphy in chronic peritoneal dialysis patients

BACKGROUND

A variety of factors can adversely impact chronic peritoneal dialysis (CPD) as an effective renal replacement therapy for patients with end-stage renal disease. These factors include peritonitis, poor clearances, loss of ultrafiltration, and a variety of anatomic problems, such as hernias, peritoneal fluid leaks, loculations, and catheter-related problems caused by omental blockage. This study reviews our experience with peritoneal scintigraphy for the evaluation of some of these difficulties.

METHODS

From 1991 to 1996, 50 peritoneal scintigraphy scans were obtained in 48 CPD patients. Indications for scintigraphy were evaluated, and the patients were placed into four groups: group I, abdominal wall swelling; group II, inguinal or genital swelling; group III, pleural fluid; and group IV, poor drainage and/or poor ultrafiltration. A peritoneal scintigraphy protocol was established and the radiotracer isotope that was used was 2.0 mCi of 99mtechnetium sulfur colloid placed in two liters of 2.5% dextrose peritoneal dialysis solution.

RESULTS

Ten scans were obtained to study abdominal wall swelling, with seven scans demonstrating leaks; six of these episodes improved with low-volume exchanges. Twenty scans were obtained to evaluate inguinal or genital swelling, and 10 of these had scintigraphic evidence for an inguinal hernia leak (9 of these were surgically corrected). One of four scans obtained to evaluate a pleural fluid collection demonstrated a peritoneal-pleural leak that corrected with a temporary discontinuation of CPD. Sixteen scans were obtained to assess poor drainage and/or ultrafiltration. Five of these scans demonstrated peritoneal location, and all of these patients required transfer to hemodialysis. The other 11 scans were normal; four patients underwent omentectomies, allowing three patients to continue with CPD.

CONCLUSION

Peritoneal scintigraphy is useful in the evaluation and assessment of CPD patients who develop anatomical problems (such as anterior abdominal, pleural-peritoneal, inguinal, and genital leaks) and problems with ultrafiltration and/or drainage.

Evaluating patients with renal failure for renal artery stenosis with gadolinium-enhanced magnetic resonance angiography

The incidence and prevalence of end-stage renal disease (ESRD) continues to increase, especially in the elderly population. The role of renovascular disease in contributing to ESRD is still not well defined. The objective of this study was to determine the utility of gadolinium (Gd)-enhanced magnetic resonance angiography (MRA) in evaluating elderly patients with renal insufficiency for renal artery stenosis (RAS). A 7-month prospective study conducted in a tertiary referral center evaluated 40 consecutive patients with progressive renal insufficiency (18 men and 22 women; mean age, 70 +/- 5.6 [standard deviation] years) and high clinical suspicion for renovascular disease with Gd-enhanced MRA. Digital subtraction angiography (DSA) was obtained in only those patients with significant RAS detected by MRA. Twelve patients had significant RAS. Six of these patients had percutaneous transluminal renal angioplasty (PTRA), five patients had renal artery bypass surgery, and one patient had a stent placed after PTRA. Seventy-eight renal arteries were satisfactorily evaluated by MRA. Twenty-two renal arteries were evaluated by both MRA and DSA. Of the 12 significant stenoses detected by the MRA, 11 were confirmed by DSA and 1 was confirmed at the time of surgical revascularization. It is concluded that Gd-enhanced MRA is a useful test for the evaluation of RAS in patients with compromised renal function.

Continuous cycler therapy, manual peritoneal dialysis therapy, and peritonitis

An increasing number of patients are prescribed a continuous-cycling regimen because standard manual peritoneal-dialysis exchanges alone are not sufficient in achieving adequate dialysis as defined by the Dialysis Outcome Quality Initiative. Consequently, the number of patients on continuous-cycler therapy is increasing. There is controversy as to whether there are differences in the development of peritonitis between patients maintained on manual therapy and those on continuous cycling therapy. As a result, we retrospectively reviewed the charts of all cycler peritoneal dialysis (CPD) patients maintained on either manual peritoneal dialysis (Baxter UltraBag; Group I) or continuous cycler peritoneal dialysis (Baxter HomeChoice Cycler; Group II) between 1 June 1994 and 31 December 1996. A total of 239 patients were in Group I and 106 in Group II. Both groups were similar in age, race, gender, and presence of diabetes mellitus, coronary artery disease, peripheral vascular disease, and gastrointestinal disease. There was no difference in the overall rate of peritonitis between the two groups of patients [1 episode in 10.4 patient-months (Group I) vs. 1 in 10.0 patient-months (Group II); -0.01843 to 0.02619]. The rates of Staphylococcus aureus peritonitis [1 episode in 48.5 patient-months (Group I) vs. 1 in 141.8 patient months (Group II); -0.06152 to -1.1689]; polymicrobial peritonitis [1 episode in 278.8 patient-months (Group I) vs. 1 in 1134 patient months (Group II): -0.0079 to -0.0478], and fungal peritonitis (1 episode in 202.7 patient-months (Group I) vs. no episodes (Group II); 0.00202 to 0.00785] were significantly lower among patients maintained on the Baxter HomeChoice Cycler. The rate of gram-negative peritonitis was higher among patients maintained on the Baxter HomeChoice Cycler, but this difference was not statistically significant [1 episode in 82.6 patient-months (Group I) vs. 1 episode in 45.4 patient months (Group II); 0.4723 to -0.0248]. We conclude that individual rates of peritonitis were different for patients maintained on either manual or continuous CPD therapy, while the overall rate of peritonitis was found to be similar for both groups of patients. The finding that there may be a difference with the gram-negative peritonitis rate is important since gram-negative peritonitis has been shown to have a more severe outcome in terms of morbidity, mortality, and patient dropout from CPD therapy. A larger, randomized, multicenter study comparing the rates of gram-positive, gram-negative, fungal, and polymicrobial peritonitis is warranted.

Adequacy of CPD: comparing Kt/V and creatinine clearance

Presently, adequate dialysis in continuous peritoneal dialysis (CPD) patients is assessed by monitoring urea kinetics (Kt/V) or by measuring the total creatinine clearance (CC). Target Dialysis Outcome Quality Initiative (DOQI) goals are a weekly Kt/V of at least 2.0, and a CC of at least 60 L/wk per 1.73 m2. One hundred and four CPD patients in the New Haven continuous ambulatory peritoneal dialysis (CAPD) unit had their most recent Kt/V and CC reviewed. Of these patients, 58.7% attained the DOQI goals for Kt/V and CC, 14.4% had an acceptable Kt/V but low CC, 11.5% had an acceptable CC but low Kt/V, and 15.4% had both low Kt/V and low CC. A CC > 60 L/week per 1.73 m2 was associated with a residual renal function of > 25 L/wk per 1.73 m2. For a Kt/V of > 2.0, good residual renal function was helpful but not essential. A question left unanswered is whether patients with a low Kt/V and an adequate CC or low CC and acceptable Kt/V need more dialysis.

Psychosocial factors and clinical outcome on CAPD

Patient dropout from chronic peritoneal dialysis (CPD) and transfer to hemodialysis remains a major problem with patients on CPD. Peritonitis, exit-site infections, and medical complications requiring hospitalization often adversely affect the outcome of CPD. The role of psychosocial factors in determining patient outcome and influencing the rates of these complications is not clear. Our group has employed a variety of instruments, including the Patient Related Anxiety Scale (PRAS), Beck's Depression Inventory (BDI), Kupfer-Detre System II somatic symptom scale (KDS-II), and a patient self-assessed quality of life (PAQOL) questionnaire to assess quality of life and to objectively evaluate the psychosocial status of the patient treated with CPD. The present study extends previous observations by relating the results of these psychosocial instruments to the incidence of various complications in 103 patients maintained on CPD. Patients were divided into low-scoring (lowest symptoms of depression, anxiety, somatic symptoms, and best quality of life evaluation), intermediate, and high-scoring (highest symptoms of depression, anxiety, somatic symptoms, and worst quality of life) categories. The peritonitis rates, exit-site infection rates, and days of hospitalization of the three categories were then compared. The results demonstrate significantly higher complication rates in the high-scoring when compared to the low-scoring patients. Thus screening patients maintained on CPD with objective measures of psychosocial functioning may enable caregivers to more accurately predict which patients are at greater risk for developing medical complications.

Quality of life assessment in chronic peritoneal dialysis patients

Previous studies by our group have attempted to examine quality of life (QoL) issues in a cohort of end-stage renal disease (ESRD) patients maintained on chronic peritoneal dialysis (CPD) by assessing a variety of psychological tests and by asking patients to rate their own QoL. The present study was undertaken to extend previous observations by asking patients to spontaneously select those domains of life experience that they think are most important in determining their quality of life. Sixty-eight medically stable CPD patients were asked to spontaneously select those three to five domains felt to be most important to them in defining their QoL. The 307 responses were then grouped into 22 broad categories by three investigators. The most frequently selected domains focused on interpersonal relationships. Domains that enhance the quality of one's day and add meaning to one's life were selected with a midrange frequency. Some domains that might intuitively seem to be important for a patient's QoL were selected with a surprisingly low frequency. These findings suggest that to understand what CPD patients value in assessing their QoL can best be determined by asking them directly and not by using predetermined variables.

Nine episodes of CPD-associated peritonitis with vancomycin resistant enterococci

Nine episodes of chronic peritoneal dialysis (CPD)-associated peritonitis with vancomycin resistant enterococci (VRE) were described between November 1993 and February 1996 in our dialysis unit. During the time period, 216 patients were treated for 227 episodes of peritonitis. Of the patients developing peritonitis with VRE the mean age +/- SD was 56.3 +/- 9.7 years. There were 5 females, 4 males, 5 Caucasians and 4 African-Americans. Diabetes mellitus, cardiovascular disease and gastrointestinal disease were present in 7, 8 and 7 of the 9 patients with VRE peritonitis, respectively. Patients were maintained on CPD therapy for an average of 29.9 +/- 19.2 patient months before developing VRE peritonitis. The prior rate of CPD associated peritonitis in the patients developing VRE peritonitis was significantly higher than the rate noted in the CPD patients not developing peritonitis with VRE (1 episode in 6.3 patient months vs. 1 episode in 12.5 patient months, P < 0.05). All 9 patients had used vancomycin in the six months prior to the development of VRE peritonitis and 78% had used a cephalosporin. The antimicrobial therapy used to eradicate peritonitis with VRE varied among the 9 patients with chloramphenicol used in 4 patients. The Tenckhoff catheter was removed in 6 of the 9 patients and was successfully reinserted in one patient. The catheter was not removed in 3 patients and 2 of these patients expired. Five of the 9 patients expired while being treated for VRE, 2 transferred to hemodialysis and 2 continued CPD therapy. VRE peritonitis is a major concern for patients maintained on CPD therapy. Future studies are needed with case controls to determine the significance of prior vancomycin and cephalosporin therapy, fecal VRE carriage and certain demographic data on the acquisition of VRE peritonitis. Furthermore, the optimal therapy and outcome may be better clarified through such a review.

Continuous peritoneal dialysis-associated peritonitis of nosocomial origin

OBJECTIVE

To describe our experience with nosocomial continuous peritoneal dialysis (CPD)-associated peritonitis focusing on the incidence, possible risk factors, spectrum of organisms, and outcome.

DESIGN

Retrospective review of the medical records of our CPD patients admitted to an acute-care hospital between November, 1993 and December, 1994.

SETTING

University-associated acute-care hospitals in New Haven, Connecticut.

PATIENTS

One hundred and eighty-eight patients maintained on CPD therapy and admitted to an acute-care hospital.

RESULTS

Nineteen patients (5%) developing nosocomial peritonitis (NP) were identified from the 408 admissions occurring during the study period. Patients developing NP were older than the hospitalized CPD patients not developing NP (65.5 +/- 14.6 vs 58.4 +/- 14.7 years, p < 0.05). Comorbid diseases including diabetes, peripheral vascular disease, gastrointestinal disease, cardiovascular disease, and human immunodeficiency virus seropositivity were not more common in the patients developing NP. Patients developing NP were hospitalized significantly longer than the CPD patients not developing NP (39.5 +/- 46.5 days vs 12.7 +/- 12.4 days, p < 0.001). The mean serum albumin was lower in the NP patients than in the CPD patients not developing NP (2.35 +/- 0.52 g/dL vs 3.02 +/- 0.60 g/L, p < 0.001). Antecedent antibiotic use and performance of invasive procedures were noted in 89% and 68% of the patients developing NP, respectively. Staphylococcal species, enterococcal species, and gram-negative organisms accounted for 26%, 21%, and 53% of the episodes of NP, respectively. Furthermore, two strains of Enterococcus resistant to vancomycin were cultured. Eight patients developing NP expired, 8 patients continued CPD therapy, 2 patients transferred to hemodialysis, and one patient recovered renal function.

CONCLUSION

We conclude that NP is uncommon. Increased age, increased length of hospital stay, and hypoalbuminemia may predispose patients to the development of NP. Further studies with case controls should help to clarify whether antecedent antibiotics or prior performance of invasive procedures predispose patients to the development of nosocomial peritonitis. The spectrum of organisms accounting for NP is different than the spectrum of organisms causing community-acquired CPD-associated peritonitis. Some of these organisms may be resistant to standard antibiotic therapies. Patients developing NP do poorly, with 42% expiring while being treated for NP.

Sexual experience of the chronic peritoneal dialysis patient

The actual and desired frequency of intercourse was studied in 68 randomly selected chronic peritoneal dialysis (CPD) patients. The results were correlated with standard measures of depression (Beck Depression inventory), anxiety (Patient Related Anxiety Scale), physical symptoms (Kupfer-Detre System 2), adequacy of dialysis (KT/Vurea) and nutrition (serum albumin level). In addition, patients assessed their quality of life (PAQOL) using an 1 to 10 analog scale. The mean +/- SD age of all patients studied was 54 +/- 11 yr, the mean dialysis duration was 24 +/- 24 months; 46% of the patients were female, and 34% were diabetic. Sixty-three percent of the patients reported never having intercourse (Group 1), 19% reported having intercourse < or = two times per month (Group II), and 18% reported having intercourse > two times per month (Group III). Dialysis duration, serum albumin level, KT/Vurea, and age were not significantly different among the three groups. Nearly 50% of patients in Group I desired to have intercourse, and 54% of the patients in Group II desired to have intercourse more frequently, Group I patients had significantly higher depression and anxiety scores, more physical symptoms, a poorer overall PAQOL, and less satisfaction with their sexual activity than Group III patients. These results suggest that there is a high prevalence of sexual difficulties in CPD patients. Patients not having intercourse have a poorer quality of life and higher degree of depression and anxiety than patients having intercourse more than two times per month.

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.

Quality of life in peritoneal dialysis patients

In 49 patients receiving continuous ambulatory peritoneal dialysis, we assessed the relative influences of adequacy of dialysis (assessed by kinetic transfer/volume urea) and psychological symptoms (depression and anxiety) upon the patients' evaluation of their overall quality of life (QoL). Subjects completed self-rating forms for anxiety, depressive, and somatic symptoms, for discrete areas relevant to QoL, and for overall QoL; clinicians also rated QoL. Depressive symptoms proved a much stronger correlate of overall QoL than did the biochemical measure of dialysis adequacy, and they remained influential even after adjustment for anxiety, kinetic transfer/volume, and somatic symptoms. In contrast, the effects of kinetic transfer/volume, anxiety symptoms, and somatic symptoms dropped sharply when adjusted for the other variables. Because psychological (especially depressive) symptoms may be stronger determinants of patients' overall QoL than is adequacy of dialysis, assessing QoL and psychological status should be part of the care of end-stage renal disease patients.

Outcome of polymicrobial peritonitis in continuous ambulatory peritoneal dialysis patients

Polymicrobial peritonitis is a relatively uncommon, but potentially serious complication that develops in continuous ambulatory peritoneal dialysis (CAPD) patients. Its cause and optimal management remain controversial. The authors reviewed the frequency and natural history of polymicrobial peritonitis in 432 CAPD patients. Of 1,405 episodes of peritonitis, 80 were polymicrobial (6%). Patients with polymicrobial peritonitis were similar to all CAPD patients in age, gender, race, and underlying renal disease. Diabetes mellitus, human immunodeficiency virus (HIV) status, and clinically apparent gastrointestinal disease did not predisposes patients to polymicrobial peritonitis. Thirty days after the polymicrobial peritonitis, 64 patients remained on CAPD (80%), and at 180 days 48 patients continued CAPD. Prior exit-site infections were present in 12 patients (14%) with polymicrobial peritonitis. Only 22% of patients required catheter removal to treat the infection. We conclude that polymicrobial peritonitis accounts for 6% of the total episodes of peritonitis; diabetes, HIV infection, and underlying gastrointestinal disease are not more prevalent in patients with multiorganism infections. Most patients continue CAPD therapy at 30 and 180 days after the episode of polymicrobial peritonitis.

Abdominal abscesses complicating peritonitis in continuous ambulatory peritoneal dialysis patients

Ten patients with end-stage renal disease maintained on continuous ambulatory peritoneal dialysis therapy developed abdominal abscesses between 1982 and 1992. During this period, 537 patients cared for in our continuous ambulatory peritoneal dialysis unit developed 1,345 episodes of peritonitis. All abdominal abscesses were attributed to concomitant or antecedent peritonitis, suggesting that abscesses developed in 0.7% of peritonitis episodes. Abdominal pain, tenderness, fever, and nausea and vomiting were the most common presenting symptoms and signs. Radiographic findings that were helpful in establishing the diagnosis included abnormalities on computed tomography (CT) scanning, ultrasound, and Indium scanning. Seven patients developed intraperitoneal abscesses, two developed abdominal wall abscesses, and one developed both abdominal wall and intraperitoneal abscesses. Drainage of the abscesses was performed in all cases either surgically or percutaneously. Two patients died. The remaining eight patients have been maintained on hemodialysis therapy. The present data suggest that abdominal abscesses are uncommon complications of continuous ambulatory peritoneal dialysis-associated peritonitis. Prompt diagnosis by clinical criteria and radiographic techniques is important to permit appropriate drainage of the abscess cavity.

Outcome of HIV infected patients on continuous ambulatory peritoneal dialysis

A retrospective analysis of 39 HIV infected patients with ESRD cared for in New Haven from 1987 to June 1992 was performed. All patients had evidence for HIV infection at the start of CAPD therapy. Cumulative technique survival at one and two years was 43% and 27%, respectively. Only eight patients transferred to center dialysis. One and two year patient survival on CAPD was 58% and 54%, respectively. Mortality was higher in patients with advanced infection than in those with asymptomatic HIV infection. Hospitalization rates were also higher in patients with advanced infection. HIV infected patients had higher rates of peritonitis (3.9 episodes/outpatient CAPD year) compared to non-HIV infected patients (1.5 episodes/CAPD year), especially for pseudomonal and fungal infections. Active injection drug use and use of the "straight set" system were associated with increased rates of peritonitis. CAPD deserves consideration as a therapy for HIV infected patients with ESRD.