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.

The incident patient cohort study design with uncontrolled dose. Substantial over-estimation of mortality as a function of peritoneal dialysis dose?

In the Canada-USA (CANUSA) Study, the dialysis dose was neither randomized nor held constant, was measured at 6 month intervals, and the relative risk of mortality (R) was found to correlate linearly to mean values of weekly peritoneal plus renal urea clearance normalized to volume, (KprT/ V)m, ranging from 1.5 to 2.3. A risk/dose (R/D) function was derived for continuous ambulatory peritoneal dialysis from kinetic criteria for dose equivalency in hemodialysis (HD) and peritoneal dialysis (PD) and the HD R/D function. This PD R/D function was nonlinear with breakpoint from steep to shallow slope at (KprT/V)ud = 2.00, where ud refers to uniform single doses in contrast to mean doses with wide variances on the mean. The predicted decrease in renal urea clearance KrT/V per 6 months of CANUSA follow-up was computed from serial measured KrT/V in the Randomized Dialysis Prescription and Clinical Outcomes Study and showed it to be 0.21 +/- 0.34. The CANUSA (KprT/V)m values were corrected for the distributed values of 3 months decrements in KrT/V, and the population mortality risk at each (KprT/V)m dose level reported in CANUSA was computed from summation of the product of the R/D curve and fractional distribution of (KprT/V)ud values. From these calculations, the authors conclude that maximum (KprT/V)ud level achieved in CANUSA was 2.00, and the study does not define R/D response above this level.

CAPD prescription in current clinical practice.

A total of 132 patients from 15 dialysis centers were studied. Analyses were made of each drained dialysate exchange over 24 hours to determine total peritoneal urea clearance (KpT, liters/day), and a 24-hour urine was collected to determine total renal urea clearance (KrT, liters/day) and the sum of KpT+KrT or KprT, liters/day. Body water volume (V, L) was estimated from gender and surface area, and daily fractional urea clearance (KprT/V) was calculated. Normalized protein catabolic rate (PCRN, grams/kilogram/day) was also calculated from the urea data. Major results were the following: KrT comprised 25% of KprT; the mean KprT/V was 0.28, but ranged from 0.10-0.50; an equivalent thrice-weekly hemodialysis KT/V was calculated from the KprT/V values and showed mean KT/V = 1.07, but 67% of values were less than 1.0. In contrast, the Health Care Finance Administration (HCFA) consensus criteria indicated 91% of prescriptions were adequate. These data indicate the need for clinical outcome studies with KprT/V randomized over the range 0.20-0.30 to better define the domain of adequate CAPD.

End-stage renal disease and the practice of nephrology.

Data from a national survey of 336 nephrologists who provide dialysis care on capitation reimbursement show differences in practice activity associated with the proportion of patients with end-stage renal disease (ESRD). On the average, ESRD patients account for 53% of patients seen by these physicians. Nephrologists who have the majority of their visits with ESRD patients average more than 120 patient encounters per week, approximating the practice workloads of primary care physicians. Nephrologists spend comparable amounts of time providing treatment for ESRD and non-ESRD patients in the same settings, schedule additional office visits for facility dialysis patients, and provide treatment and advice for problems not related to dialysis. Whereas care for acute renal failure patients is primarily based on consultations and involves a narrow focus, treatment for ESRD involves the provision of comprehensive primary medical care by nephrologists to their patients being treated with dialysis.

Case-mix and treatment in end-stage renal disease: hemodialysis v peritoneal dialysis.

The University of Southern California School of Medicine conducted a nationwide survey of 336 nephrologists to obtain demographic and clinical data on 6,411 patients with end-stage renal disease (ESRD). Patient demographic data, along with ESRD etiology and comorbid conditions noted by the physician, were compared across various modalities of dialysis. Characteristics of the treatment provided were differentiated by the mode of dialysis and the location of the patient encounter. Results of the analysis show that patients on peritoneal dialysis are more likely to be female and have higher rates of diabetes compared with hemodialysis (HD) patients. Statistically, patients on intermittent peritoneal dialysis are older, more likely to be black, and have a higher incidence of cardiovascular conditions. Continuous ambulatory peritoneal dialysis patients have greatest problem severity and require more physician time and more complex services, whereas home HD patients require the greatest number of diagnostic tests and therapeutic procedures. Hospital inpatient care shows greater case-mix severity and more intensive treatment, but this does not differ by the mode of dialysis. Finally, patients of freestanding dialysis facilities are more likely to have hypertensive renal disease, whereas patients at hospital-based facilities are older, more likely to be seen in the hospital, have more urgent and severe problems during dialysis rounds, and require more physician time, more complex services, and more diagnostic tests and therapeutic procedures.

Morbidity and mortality of continuous ambulatory peritoneal dialysis: regional experience and long-term prospects.

The Network Coordinating Council (NCC) #4 continuous ambulatory peritoneal dialysis (CAPD) study was designed to gather basic demographic information and analyze selected outcome parameters on all patients started on CAPD in Southern California/Southern Nevada. Between early 1979 and Dec 31, 1983, 775 patients were enrolled in the study for a total experience of 878.5 patient-years. Demographic data revealed 25% of patients were over 60 years old and 17.4% were less than 20 years old at the start of CAPD, 65% were white, and 28% had chronic glomerulonephritis as a cause of end-stage renal disease (ESRD). Compared to all NCC #4 patients on dialysis (hemo and peritoneal), the young (less than 20 years old) and whites were overrepresented on CAPD. Patient outcome was assessed by life table analysis which revealed 90%, 80%, 70%, and 70% patient survival at 12, 24, 36, and 43 months, respectively; and technique success of 80%, 60%, 48%, and 40% for the same time periods, respectively. Over half of the dropout from CAPD and one third of the hospitalizations were related to recurrent infection. Few patients transferred from CAPD because of dissatisfaction with the technique or because of peritoneal membrane failure. CAPD is an excellent form of therapy for ESRD that controls uremia adequately and improves the quality of life for many patients. Long-term application of CAPD is hampered, however, by the high frequency of recurrent infections.

Interlaboratory evaluation of the AOAC method and the A-1 procedure for recovery of fecal coliforms from foods.

An interlaboratory evaluation was made of the 96 h AOAC method and the 24 h A-1 procedure for the enumeration of fecal coliforms in samples of yellow corn meal, rye flour, mung beans, raw ground beef, and raw oyster homogenate. Results indicated that the efficiency of the A-1 procedure, measured in terms of recovery of fecal coliforms, and the reproducibility of that recovery were dependent on the particular food being analyzed. Accordingly, until its efficiency can be more fully demonstrated, the A-1 procedure is recommended only as a screening procedure for fecal coliforms in foods.

Hemodialysis and renal transplantation in patients with hypernephroma.

Of five patients with hypernephroma who were maintained on hemodialysis after nephrectomy, four died with metastic disease after having been on hemodialysis for an average of 13.7 months (range 8 to 19). The fifth patient had no evidence of malignancy after 21 months of dialysis; he then received a renal allograft from his sister, and did well for 24 months before he developed liver metastasis. We believe hemodialysis is an appropriate mode of treating the renal failure of patients with hypernephroma after therapeutic nephrectomy. These patients may be considered for renal transplantation after a period of hemodialysis, and we suggest the currently recommended 12-month waiting period before transplantation be extended to 18 to 24 months. Use of living related donor renal allograft in these patients is questionable.

Usefulness of the stomacher in a microbiological regulatory laboratory.

The relative efficiency of the Waring blender, the Stomacher 400, and the Stomacher 3500 for preparing food samples for microbiological analysis was studied. Comparative aerobic plate count (APC) values were determined on 671 samples, representing 30 categories of foods. Of the 26 categories of nonfatty foods, the blender gave significantly higher geometric mean APC values than those given by the Stomacher 400 and the Stomacher 3500 in 65 and 69 percent of the categories, respectively. In a comparison of the two Stomacher models, the Stomacher 400 gave significantly higher geometric mean APC values than these given by the Stomacher 3500 in 73 percent of the food categories. Addition of Tween 80 to four categories of fatty foods at concentrations of 0.5, 1.0, and 2.0 percent did not raise the APC values given by either model of stomacher to the levels given by the Waring blender. Overall, the efficiency of both models of Stomacher, relative to the blender and to each other, was specific and depended upon the particular food being analyzed.