Nutritional markers during peritoneal dialysis: data from the 1998 Peritoneal Dialysis Core Indicators Study.

OBJECTIVE: This analysis explores the nutritional status of adult U.S. peritoneal dialysis (PD) patients. DESIGN: The Peritoneal Dialysis Core Indicators Study is a prospective cross-sectional prevalence survey describing the care provided to a random sample of adult U.S. PD patients. METHODS AND POPULATION: Prevalence data were collected from a national random sample of 1381 adult PD patients participating in the United States End Stage Renal Disease (ESRD) program. RESULTS: The median age of these patients was 55 years, 61% were Caucasian; the leading cause of ESRD was diabetes mellitus. Age, sex, size, peritoneal permeability, dialysis adequacy, and nutritional indices did not differ between patients on continuous ambulatory PD and patients on automated PD. The dialysis prescriptions employed achieved mean weekly Kt/V urea (wKt/V) and creatinine clearance (wCCr) values of 2.22 +/- 0.57 and 67.8 +/- 22.5 L/1.73 m2/week, respectively. The PD patients were large, with a mean body weight of 77 +/- 21 kg and body mass index (BMI) of 27 +/- 8.6 kg/m2. The mean serum albumin of these patients was 3.5 +/- 0.51 g/dL, and 43% of values fell below the National Kidney Foundation Dialysis Outcomes Quality Initiative's desired range. The PD patients had a normalized protein equivalent of nitrogen appearance (nPNA) of 1.0 +/- 0.57 g/kg/day, a normalized creatinine appearance rate (nCAR) of 17 +/- 7.3 mg/kg/day, and an estimated lean body mass (%LBM) of 62% +/- 18% of body weight. Serum albumin correlated positively with patient size, nCAR, and nPNA, but negatively with age, the presence of diabetes mellitus, female gender, erythropoietin dose, the creatinine dialysate-to-plasma ratio results of peritoneal equilibration testing, and the dialysis portion of the wCCr. The duration of ESRD experience correlated negatively with both serum albumin and patient size, although these relationships were complex. CONCLUSION: Peritoneal dialysis patients generally have marginal serum albumin levels, a finding incongruent with alternative measures of nutritional status, such as weight, BMI, and creatinine generation. Serum albumin is reduced in patients with high peritoneal permeability (i.e., rapid transporters) and, because these patients generally have higher than average wCCr values, serum albumin is inversely correlated with the dialysis component of the wCCr. The presumptive nutritional indicators (BMI, %LBM, nPNA, and serum albumin) provide disparate estimates, varying from 10% to 50% for the prevalence of nutritionally stressed PD patients.

Cardiovascular comorbidity and mortality in patients starting peritoneal dialysis: an American midwestern center experience.

End-stage renal disease (ESRD) patients frequently have multiple comorbidities, and cardiovascular disease remains the leading cause of death in these patients. The objectives of the present study were (1) to characterize the number and severity of cardiovascular comorbidities at the start of peritoneal dialysis (PD), and (2) to determine the impact of these comorbidities on mortality. We retrospectively studied all ESRD patients starting peritoneal dialysis at our center between 1990 and 1999. The baseline cardiovascular comorbid factors were categorized as ischemic heart disease, congestive heart failure, arrhythmia, peripheral vascular disease, and cerebrovascular disease. The severity of each factor was scored from 0 to 3. The number of comorbidities and the total cardiovascular comorbidity severity scores were determined for each patient. Cardiovascular deaths included those attributed to sudden death, cardiac disease, cerebrovascular disease, and complications of peripheral vascular disease. Of the 191 patients, 105 were men, and 105 (55%) had diabetes mellitus. The mean age was 60.8 +/- 13.3 years and the mean time on PD was 18.8 +/- 16.3 months. As the number of cardiovascular comorbidities increased, the proportion of patients who died of cardiovascular causes increased eighteen-fold. At each level of cardiovascular comorbidity, diabetic patients starting dialysis were younger, and their survival time was shorter as compared with non diabetic patients. Baseline comorbidity determination is important, as comorbidities are prognostic harbingers of eventual complications.

Erythropoietin and iron use in peritoneal dialysis patients. Report from the 1997 HCFA end-stage renal disease core indicators project.

The HCFA ESRD Core Indicators Project is designed to assess several key indicators of care in peritoneal dialysis patients, including anemia management. Information on hematocrit levels, epoetin alfa dosing, estimates of iron stores, and iron therapy as obtained in a national sample of 1,219 peritoneal dialysis patients are described. The average hematocrit was 32.8% +/- 3.8%, and severe anemia (hematocrit < 25%) occurred in 1.4% of PD patients. The mean weekly epoetin alfa dose was 134.6 U/kg. In general, there was an inverse relationship between hematocrit and epoetin alfa doses. Most (83%) of PD patients received iron therapy, with only 8% of patients receiving intravenous iron. The mean serum ferritin was 303 ng/mL, with 64% of patients having a ferritin greater than 100 ng/mL. The mean transferrin saturation was 28%, with 60% of patients having a value of less than 20%. There was an inverse relationship between serum ferritin levels and hematocrit but no relationship between hematocrit and transferrin. It is concluded that there could be improvement in the epoetin alfa and iron management in many patients.

Trends in clinical indicators of care for adult peritoneal dialysis patients in the United States from 1995 to 1997. ESRD Core Indicators Workgroup.

BACKGROUND: This article describes the changes in four core indicator variables: dialysis adequacy, hematocrit, serum albumin, and blood pressure in peritoneal dialysis CAPD and cycler patients over a three-year period. METHODS: A national random sample of adult peritoneal dialysis patients in the United States was drawn each study period. Clinical data abstraction forms were completed by facility staff for patients selected for the sample, returned to the respective network, then forwarded to the Health Care Financing Administration for analysis. RESULTS: The mean weekly Kt/V urea for CAPD patients increased from 1.91 in 1995 to 2.12 in 1997 (P < 0.001) and for cycler patients, from 2.12 in 1996 to 2.24 in 1997 (P < 0.05). The mean weekly creatinine clearance for CAPD patients increased from 61.48 liter/week/1.73 m2 in 1995 to 65.84 liter/week/1.73 m2 in 1997 (P < 0.05). For cycler patients, it increased from 63.37 liter/week/1.73 m2 in 1996 to 67.45 liter/week/1.73 m2 in 1997 (P < 0.05). Despite this increase in adequacy values, less than 40% of peritoneal dialysis patients in 1997 had weekly Kt/V urea or creatinine clearance values that met subsequently published National Kidney Foundation's Dialysis Outcomes Quality Initiative (DOQI) guidelines. These data suggest that the dialysis prescription may not be adequately modified to compensate for increased body weight and for decreased residual renal function as years on dialysis increase. The average hematocrit value increased modestly in both CAPD and cycler patients from 1995 to 1997, and the number of patients with a hematocrit of less than 25% decreased from 6% in 1995 to 1.4% in 1997 (P < 0.001). Both serum albumin values and systolic and diastolic blood pressure values were essentially unchanged during the three-year period of observation. CONCLUSIONS: Despite improvements in dialysis adequacy and hematocrit values, there remains much room for improvement in these core indicator values.

Long-term, successful peritoneal dialysis: end-stage renal disease core indicators study data.

The proportion of U.S. dialysis patients using peritoneal dialysis (PD) continues to fall. The reasons for the decline are presumably related to reduced patient recruitment and poor patient retention (technique failure). Yet, the 1998 Peritoneal Dialysis Core Indicators Study (PD-CIS) report suggests that PD provides satisfactory "long-term" renal replacement for many patients, and, further, that this capacity is becoming more obvious and is beginning to mimic center hemodialysis results. Several patient characteristics suggest that the key to successful "long-term" PD involves the delivery of "adequate dialysis" and that increasing attention to PD prescription and dialysis delivery has been accompanied by an improvement in PD technique success.

1996 Peritoneal Dialysis Core Indicators Study: report on nutritional indicators.

OBJECTIVE: The 1996 Peritoneal Dialysis Core Indicators Study illustrates the conduct of peritoneal dialysis in the United States during 1996. DESIGN AND PATIENT POPULATION: The survey is a medical records audit of 1317 randomly selected adult U.S.A. Medicare patients using peritoneal dialysis during 1996. OUTCOME MEASURES: Abstracted data included basic demographic characteristics, dialysis prescription, delivered dialysis dose, residual renal function, serum albumin, hematocrit, anemia management, and patient status. RESULTS: The survey included 785 patients using continuous ambulatory peritoneal dialysis (CAPD) and 423 using automated peritoneal dialysis (APD) primarily in the form of continuous cycling peritoneal dialysis (CCPD). Except for the prescription mechanics and a greater likelihood that African-Americans would use CAPD, the groups did not differ substantially from one another. Evaluation of patient weight (W), body mass index (BMI), residual renal function, average serum albumin, protein equivalent of nitrogen appearance (nPNA), and dialysis efficiency as weekly fractional urea nitrogen removal (wKt/Vurea) and weekly creatinine clearance (wCrCl) revealed a picture of reasonable dialysis delivery and marginal protein nutrition. Additionally, there was little evidence that "dialysis efficiency," over the range assessed, had a major influence on nutritional status. Despite a tendency toward obesity (body weight = 76.6+/-20.0 kg and BMI = 27+/-7), 47% of patients had an average serum albumin below"normal" (3.5 g/dL by bromcresol green) and 70% had a nPNA below 1.0 g/kg/day. CONCLUSIONS: Peritoneal dialysis patients appear to have marginal protein reserves despite surfeit energy stores.

Nephrology nurses' perceptions of barriers and facilitators to using research in practice.

OBJECTIVE: The purpose of this study was to determine nephrology nurses' perceptions of barriers to research utilization and to identify effective ways to facilitate integration of research findings in nephrology nurses' practice. DESIGN: This was an explorative, descriptive study. SAMPLE/SETTING: Four hundred ninety-eight nephrology nurses participated in the study. The primary areas of clinical practice were hemodialysis (36%), peritoneal dialysis (29%), transplantation (15%), pediatric nephrology (3%), or various combinations (18%). METHODS: Participants completed a demographic data form and the previously validated instrument, Barriers and Facilitators to Using Research in Practice. Descriptive statistics were used to analyze the data. RESULTS: The majority of respondents (52%) were staff nurses. The other respondents included 30% in management, 12% in advanced practice roles, and 6% in education. The barriers to research utilization most frequently identified were insufficient time on the job to implement new ideas and not enough time to read research. The most effective facilitators identified were increased administrative support and encouragement, increased time available for reviewing and implementing research findings, and improved understandability of research reports. CONCLUSIONS: Additional nursing and nonnursing administrative support for research activities and designated time to read research and implement research-based clinical practices may facilitate the development of research-based nephrology nursing practice.

Six-year experience with Swan neck presternal peritoneal dialysis catheter.

BACKGROUND: The presternal peritoneal catheter is composed of two silicone rubber tubes joined by a titanium connector at the time of implantation, and has an exit on the chest. OBJECTIVE: Comparison of survival and complication rates of Swan neck abdominal catheters with those of the presternal catheter. DESIGN: Nonrandomized study with prospective collection of data between August 1991 and October 1997. SETTING: Tertiary referral center. PATIENTS: In 57 patients, 58 presternal catheters and, in 81 patients, 86 abdominal catheters were implanted. Patients chose the type of catheter; however, obese individuals and those with ostomies and previous catheter problems were encouraged to opt for the presternal catheter. Others chose the presternal catheter in order to take tub baths or use a whirlpool. MAIN OUTCOME MEASURES: Life-table analyses of catheter survival censored for transplant, transfer, and death; reasons for catheter removal due to complications; and patient satisfaction. RESULTS: Two-year survival probabilities were 0.95 and 0.75 for presternal and abdominal catheters, respectively. Nine abdominal catheters were removed due to exit/tunnel infections (including five with peritonitis), and four due to peritonitis. External cuff shaving in four presternal catheters has extended survival for more than 1 year. Four presternal catheters were removed due to peritonitis. No catheters in either group were lost due to leakage or obstruction. The peritonitis rate was 1 episode per 37.4 patient-months and 1/20.5 patient-months for presternal and abdominal catheters, respectively. These differences are not significant. Patient acceptance of the presternal catheters was excellent; in the latest period, from January to October 1997, presternal catheters were chosen by 15/24 patients. CONCLUSIONS: The trend to improved outcomes in presternal catheters continues to validate the rationale for presternal catheter design. Decreased frequency of exit/tunnel infection may be due to more effective immobilization on the chest, less trauma, and avoidance of submersion in stagnant water. No specific contraindications to use of the presternal catheter have been identified.

1996 peritoneal dialysis--core indicators report.

The 1996 Peritoneal Dialysis-Core Indicators Study (PD-CIS) retrospectively reviews a random sample of peritoneal dialysis patients from the United States End-Stage Renal Disease (ESRD) program. Peritoneal dialysis (PD) patients are more likely to have a primary diagnosis of glomerulonephritis, less likely to be of African-American heritage, and are younger than hemodialysis patients. One third of PD patients now perform some form of automated peritoneal dialysis (APD) rather than continuous ambulatory peritoneal dialysis (CAPD). The dialysis prescriptions currently employed do not appear to be based on kinetic principles, and the intensity of dialysis achieved is below the proposed minimal guidelines for 30% of patients. In 1996, the mean dialysis index or wKt/Vurea for CAPD patients was 2.0 +/- 0.5 and was not significantly altered from the 1995 value of 2.1. Eighty-four percent of CAPD patients perform four or fewer exchanges daily, and only 27% of patients have prescriptions using infusion volumes greater than 2 L. Although hematocrits have improved since 1995, 30% of PD patients have a hematocrit below 30%. The mean serum albumin for PD patients is 3.5 g/dL, and 25% of patients have a 6-month average serum albumin value below 3.2 g/dL. In general, the indices monitored as predictive of health and well-being of PD patients afford significant opportunity for improvement.

Repair of chronic peritoneal dialysis catheter.

BACKGROUND: Damage to the peritoneal dialysis catheter may be due to wear from long-term use, exposure to antibacterial agents (strong oxidants), and accidental injury from sharp objects. Repair of such catheter, if not associated with subsequent complications, would extend catheter life and reduce costs and patient inconvenience related to catheter replacement. OBJECTIVE AND DESIGN: Retrospective analysis of seven peritoneal catheters repaired 11 times over a 15-year period by splicing the old catheter with an extension tube using the Peri-Patch Repair Kit (Quinton Instrument Co., Bothwell, WA, U.S.A.). RESULTS: The life of these seven catheters was extended by a mean of 26 months (range 1-87 months), without increasing infection rates after splicing. The peritonitis rate after catheter splicing was 0.40 per year, not higher than the overall rate (0.76 per year) in our center during the same time period. Exit-site infections occurred in 6 patients after catheter splicing. Only one infection was related to trauma during the procedure and resulted in chronic exit infection; the catheter was eventually removed. In this patient, damage to the catheter was less than 1.5 cm from the exit site. CONCLUSIONS AND RECOMMENDATIONS: Splicing of the damaged peritoneal catheter, if properly done, is a safe procedure and can significantly prolong catheter life. We recommend that measures to prevent catheter damage, such as avoiding the use of scissors and other sharp objects, should be emphasized during the initial patient education and training. Alcohol and iodine should not be used on silicone rubber catheters. We suggest that the patient should report catheter damage immediately and come to the clinic within a few hours for catheter splicing (if possible) and prophylactic antibiotic to prevent peritonitis. Finally, we recommend that repair of the catheter should not be attempted if the breakage is less than 2 cm from the exit site, unless done as an emergency procedure if immediate catheter replacement cannot be performed.

Toward targets for initiation of chronic dialysis.

OBJECTIVES: To better define the targets for initiation of chronic dialysis, we compared the relationship between the normalized protein equivalent of nitrogen appearance (nPNA, g/kg standard weight/day) and weekly urea clearance (Kt) normalized to total body water (V) in predialysis chronic renal failure (CRF) patients and in patients on continuous ambulatory peritoneal dialysis (CAPD) and hemodialysis (HD). We also studied the relationships of other nutritional parameters to weekly Kt/Vurea in CRF patients. DESIGN: This cross-sectional study was a prospective observational design meant to study each patient once. SETTING: The University Hospital and Clinics and Harry S. Truman VA Medical Center, Columbia, Missouri. PATIENTS: Forty-five consecutive predialysis CRF patients were enrolled and the results compared with patients on CAPD and HD. RESULTS: In CRF, the nPNA calculated from urea appearance correlated with the weekly Kt/Vurea (r = 0.57, p < 0.0001) and, using exponential best-fit, nPNA = 1.217 x (1-e-0.769Kt/V). This exponential relationship was similar to that for CAPD and both were different from that in patients on HD. Likewise, nPNAs, calculated from Kjeldahl nitrogen output, and weekly Kt/Vurea were correlated (r = 0.37, p = 0.014) and, using exponential best-fit, nPNA = 1.102(1-e-0.867Kt/V), similar to the relationship in patients on CAPD. Evidence is presented that these relationships are not explained only by mathematical coupling. There was a significant correlation between the weekly Kt/Vurea and 24-hour urinary creatinine excretion. CONCLUSIONS: The findings suggest that in CRF, as in CAPD, a weekly Kt/Vurea less than 2.0 is likely to be associated with a nPNA less than 0.9 g/kg standard weight. In CRF patients, initiation of chronic dialysis should be considered if weekly renal Kt/Vurea falls below 2.0 and a nPNA greater than 0.8 is desired.

Report from the 1995 Core Indicators for Peritoneal Dialysis Study Group.

The 1995 Peritoneal Dialysis Core Indicators Study was conducted by the Health Care Financing Administration to ascertain standard practices and outcomes in chronic peritoneal dialysis patients. Data from 1,202 patients who did not receive hemodialysis but who were on chronic ambulatory peritoneal dialysis (CAPD) for at least part of the 6-month period between November 1, 1994, and April 30, 1995, are reported. The mean serum albumin level for this cohort was 3.5 g/dL by the bromcresol green method and 3.2 g/dL by the bromcresol purple method. Data sufficient to calculate a weekly Kt/V(urea) or weekly creatinine clearance were available for only 34% of patient submissions. In these patients, the median weekly Kt/V(urea) was 1.7 using a fixed value for V of 0.58 x body weight and was 2.0 using the Watson equation to calculate V; the median weekly creatinine clearance was 60.7 L/wk/1.73 m2. The mean hematocrit for this cohort was 32% and the average weekly recombinant human erythropoietin (rHmEPO) dose was 115 u/kg. Hematocrit values < or = 30% were found in 50% of black patients and 31% of white patients. The average blood pressure among peritoneal dialysis patients was 139/80 mm Hg, with 29% of patients having a systolic blood pressure exceeding 150 mm Hg and 18% a diastolic blood pressure greater than 90 mm Hg. In summary, serum albumin levels were significantly lower in peritoneal dialysis patients than in hemodialysis patients. Approximately one third of peritoneal dialysis patients did not have an adequacy measure obtained during the 6-month observation period. A significant minority of patients had either inadequately treated anemia of chronic renal disease or hypertension. There is an opportunity to substantially improve the medical care provided to chronic peritoneal dialysis patients.

Calculation of 6-hour D/P creatinine ratio from the 4-hour peritoneal equilibration test. The effect of dwell duration on the results.

OBJECTIVES: Since the introduction of the peritoneal equilibration test (PET), the 4-hour dialysate/plasma creatinine (D/P Cr) has been used by several authors for determining continuous ambulatory peritoneal dialysis (CAPD) prescriptions. However, the results have been unsatisfactory because the 4-hr D/P Cr does not accurately reflect the D/P Cr in 24-hr collections. The PET and the 24-hr dialysate collections differ in the duration of dwell and the tonicity and volume of dialysate, all of which influence the equilibrated D/P Cr. It can be assumed that the D/P Cr in 24-hr collections in these patients is closer to a 6-hr D/P Cr. Because a 6-hr PET is inconvenient, we developed a mathematical model to calculate the 5- and 6-hr D/P using the results of a standard PET. DESIGN: In a retrospective analysis, D/P Cr ratios in 24-hr collections and D/P Cr ratios calculated from a mathematical formula were correlated. Using a mathematical model, the data collected fit an exponential relation of the type D/P = a(1-e-t/tau). The values of a and tau are unique for a given patient and were determined using a nonlinear regression technique. The formula performed well on our published data-the true and predicted 6-hr D/P Cr being 0.696 and 0.71, respectively. SETTING: The University Hospital and Clinics, Dalton Cardiovascular Research Center and Dialysis Clinic, Inc., Columbia, Missouri. PATIENTS: All CAPD patients on four 2-L exchanges/day at the time of the 24-hr collections were included. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Closeness of 4-hr and 6-hr D/P Cr values to those of 24-hr ratios. RESULTS: The study group comprised 74 patients (age, mean +/- SEM: 56.4 +/- 1.8 yr) with 80 PETs and 145 (24-hr) collections. The interval between the two tests was 8.3 +/- 0.9 months (0-48.7 months). The median 24-hr D/P Cr of 0.760 did not differ significantly from the predicted median 6-hr D/P Cr of 0.755. A subgroup analysis, based on transport type, showed that this relationship was most precise in the high-average transporters. The predicted 6-hr D/P Cr was within 10% of the 24-hr D/P Cr in 48% of patients and within 20% in 77% of patients. The margin of error was greatest in the low transporters. CONCLUSIONS: To conclude, the 4-hr D/P Cr from a PET cannot be used interchangeably with the D/P Cr in the 24-hr dialysate collections, hence, the clearances calculated thereof will be inaccurate. Using the proposed model, it is feasible to use the 4-hr PET results to obtain 5- and 6-hr D/P Cr values. In our study, using this model, the extrapolated 6-hr D/P Cr is similar to the D/P Cr in 24-hr dialysate collections only in the high-average transporters. Hence, the best way to determine clearances in peritoneal dialysis patients is still by collecting 24-hr dialysates.

Nursing practice related to peritoneal catheter exit site care and infections.

OBJECTIVE: The purpose of the study was to obtain information from nephrology nurses on existing policies and protocols related to peritoneal catheter exit site care and treatment of exit site infections. DESIGN: This was an explorative, descriptive study. SAMPLE/SETTING: Fifty-four nurses who attended the 1995 Consensus Conference on Peritoneal Dialysis at the 26th Annual American Nephrology Nurses' Association National Symposium completed a survey questionnaire on exit site care and management of exit site infections. METHODS: A survey was mailed to nephrology nurses preregistered to attend the 1995 ANNA Consensus Conference related to peritoneal dialysis at the 26th National Symposium. Surveys were also collected at the meeting. RESULTS: Hydrogen peroxide and povidone iodine are frequently used in the nursing care of both healing and chronic exit sites. Almost all of the dialysis units require patients to stabilize or secure the catheter. The majority of respondents had a standardized method of assessing exit sites. Risk factors for exit site infections are presented for both the immediate post-catheter insertion period and the well-healed exit site. There were many different combinations of cleansing agents used to treat inflamed and infected exit sites. CONCLUSIONS: Procedures for exit site care vary widely. Prospective, randomized studies of exit site care protocols and cleansing agents are necessary to determine the most effective procedures to promote healthy exit sites.

Nursing interventions related to peritoneal catheter exit-site infections.

Nursing interventions related to peritoneal catheter exit-site infection include an emphasis on prevention and early diagnosis as well as exit-site care. The key elements to prevention of exit-site infections are avoiding trauma to the exit-site and tunnel, avoiding gross contamination of the exit-site, and cleaning a wet or dirty exit-site as soon as possible. Early diagnosis of exit-site infection is promoted by (1) teaching the patient or caregiver to assess the exit-site and tunnel routinely and to promptly recognize and report signs and symptoms of inflammation, and (2) routine exit-site evaluation by health care providers in the outpatient clinic. Care of the infected exit-site should focus on preventing cross contamination, keeping the exit-site dry, avoiding trauma and irritation, and in addition to routine care, may require removal of stubborn crusts and cauterization of proud flesh. Topical soaks and therapy have been recommended, but improvement of infected exit-sites has not been consistently documented.

Nursing interventions related to peritonitis.

Effective management of peritonitis in chronic peritoneal dialysis patients requires a multidisciplinary approach. Nursing's role begins with the prevention of peritonitis by the development of sound program policies and procedures and effective patient education. Nursing activities at the time of infection focus on assessment and patient education. Nurses are also responsible for maintaining peritonitis data as well as directing or participating in related quality improvement activities.