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Technique survival in continuous ambulatory peritoneal dialysis (CAPD) depends mostly on clearances in relation to body size and residual renal function (RRF). Our clinical impression has been that when RRF fails, larger patients leave CAPD sooner than smaller patients do. Peritoneal equilibration tests (PETs) and 24-hour adequacy evaluations performed in 277 patients in a single center from 1986 through 2009 were abstracted from the existing peritoneal dialysis adequacy database. A PET (using 2 L of 2.5% dextrose dialysis solution) was performed in 272 patients during the first 4 months of dialysis. Every 3 months, the patients brought their 24-hour urine and dialysate collections for adequacy evaluations and had height and weight recorded. Body surface area (BSA), body mass index (BMI), and total body water (TBW) were calculated. There were 1372 adequacy evaluations abstracted. The number of patients gradually declined over time because of death (28%) or transfer to other peritoneal regimens (25%) or to hemodialysis (23%). A small number of patients received a kidney graft (6%) or left CAPD for other reasons (12%); only 6% of patients remained on CAPD after 80 months of treatment. The mean (+/- standard deviation) PET 4-hour values were 0.652 +/- 0.128 for dialysate-to-plasma (D/P) ratio of creatinine (Cr), 0.403 +/- 0.0969 for 4-hour dialysate-to-initial dialysate (D/D0) glucose concentration ratio, and 2336 +/- 211 mL for the drain volume. There was no correlation between PET D/P Cr and BSA (r = 0.0051, p = 0.934), PET D/D0 glucose and BSA (r = 0.0042, p = 0.945), or PET drain volume and TBW. The correlations with other size indicators were very poor. None of the large patients (BSA > 1.9 m2, weight > 75 kg, BMI > 25 kg/m2) remained on CAPD for more than 80 months once they lost RRF. These results confirm our impression that, with declining RRF, larger patients do not continue CAPD as long as smaller patients do.

The Tenckhoff catheter was developed in 1968 and has been widely used since for chronic peritoneal dialysis (PD) patients. Variations of the Tenckhoff catheter have been designed over the years in a search for the ideal PD catheter--an access that can provide reliable dialysate flow rates with few complications. Currently, data derived from randomized, controlled, multicenter trials dedicated to testing how catheter design and placement technique influence long-term catheter survival and function are scarce. As a result, no firm guidelines exist at the national or international levels on optimal PD catheter type or implantation technique. Also, no current statistics on the use of PD catheters are available. The last survey was carried out using an audience response system at the Annual Peritoneal Dialysis Conference in Orlando, Florida, in January 1994. The present analysis is based on a new survey done at the 2005 Annual Dialysis Conference in Tampa, Florida. It is a snapshot of preferences in catheter design and implantation technique in 2004 from an international sample of 65 respondent chronic PD centers. The Tenckhoff catheter remains the most widely used catheter, followed closely by the swan-neck catheter in both adult and pediatric respondent centers. Double-cuff catheters continue to be preferred over single-cuff catheters, and coiled intraperitoneal segments are generally preferred over straight intra-peritoneal segments. Surgical implantation technique remains the prevailing placement method in both pediatric and adult respondent centers.

Peritoneal dialysis (PD)-associated peritonitis contributes significantly to morbidity and modalityfailure. The number of patients on PD is declining in Western countries, and peritonitis is a potential deterrent to the therapy. Here, we present a clinically significant decline in the rate of peritonitis at a single center over a 28-year period, with current rates significantly lower than the national average, and we review several factors that have contributed to those outcomes. Peritonitis and duration of follow-up have been recorded for all patients followed in our program since 1977. Introduction of important technological changes into the program were also recorded. All peritonitis rates are expressed as episodes/patient-year or episodes/n patient-months. Data are summarized for each calendar year since 1977. We followed 682 patients for a total follow-up duration of 15,435 patient-months. Glass bottles were changed to plastic bags in 1978. Straight connecting tubes were replaced by Y-sets in 1988. The presternal dialysis catheter was introduced in 1991 and has been the primary PD access since 1995. The peritonitis rate in 1977 was 5.8 episodes/patient-year, and that rate has progressively declined over the past 27 years to 0.35 episodes/patient-year in 2004. Technical improvements that contributed to the decline in overall peritonitis rates have been adopted nationwide. The largest improvement occurred with the switch from glass bottles to plastic bags, and to the closed-system Y-set that incorporated the flush-before-fill principle. Advances in catheter technology have also played a key role. Quality improvement in the program and long years of experience in overall care of PD patients are significant factors that cannot be measured quantitatively. Improvements have been made to exit-site care protocols, to exit-site evaluation and diagnosis, and to treatment strategies. Patient education and training in catheter care remain the important factor in a PD program. Many factors have contributed to the reduction of PD-associated peritonitis rates at our center Improved connectology, catheter care, and patient education play key roles in the reduction of peritonitis.

In the original peritoneal equilibration test (PET), which established standard values for membrane categorization in 1987, the dwell time of the preceding exchange was approximately 8 hours. Basing the test on an 8-hour prior exchange was convenient when almost all patients were on continuous ambulatory peritoneal dialysis (CAPD); however, many patients are now on some form of automated peritoneal dialysis (PD), and an 8-hour exchange before the PET requires a change in the dialysis schedule. Our goal in the present study was to determine whether the dialysate-to-plasma ratio (D/P) of solutes and the final dialysate to initial dialysate ratio (D/D0) of glucose in the short PET (2-hour equilibration time) are similar whether a 3-hour exchange or an 8-hour exchange precedes the test. The PETs were performed in 9 stable PD patients using 2 L of 2.5% dextrose dialysis solution (Baxter Healthcare, Deerfield, IL, U.S.A.). Before the equilibration exchange, the patients were on a randomly selected long (approximately 8-hour) or short (3-hour) dwell. During the equilibration exchange, dialysate samples were collected at 0.30, and 60 minutes of dwell time and from the drain bag (120-minute sample). Within a week, the PET was repeated in each patient after the alternate-length exchange. The values for D/P creatinine and urea and for D/D0 glucose were almost identical throughout the 2-hour PET after either the long or the short exchange. The D/P protein values tended to be higher in the PET after the long exchange. The short PET can be used for clinical purposes, and the creatinine and glucose results can be used for membrane categorization. Any dwell time between 3 and 12 hours is acceptable for the preceding exchange, and the equilibration test may be performed with either a 2-hour or a 4-hour dwell. The protein values obtained after a 3-hour prior dwell differ from those obtained after a long prior dwell. Protein values must therefore be standardized in a larger number of patients.

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.

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.

Peritonitis is known to acutely affect the transport characteristics of the peritoneal membrane, however, the long-term effects are not known. We studied the effect of peritoneal inflammation on mean dialysate-to-plasma creatinine concentration ratio (D/P), dialysate protein losses (DPL, g/week), and dialysate albumin losses (DAL, g/week), done at six weeks or more postepisode, in 152 patients [102 (67%) males, mean age 57 years (range 21-91)]. These patients were on continuous ambulatory peritoneal dialysis for a mean of twelve months (range 1-97). A total of 94 distinct peritonitis episodes were managed in 47 patients (31%). The number of patients with 0, 1, 2, 3, 4, and 5 episodes of peritonitis were 105, 29, 3, 6, 4, and 5. These episodes were treated with a standard protocol. There were no statistically significant differences between the D/P, DPL, or DAL between the groups. The parameters did not show any correlation to time on dialysis. Thus, in conclusion, peritonitis, if promptly treated, does not cause any permanent change in D/P, DAL, or DPL.

A previous study showed that silver-coating peritoneal catheters tended to decrease the incidence of early exit-site infections in rats. This study was designed to further evaluate the healing, biocompatability, and external tunnel morphology of standard and silver-coated catheters. Catheters were coated with silver by an ion beam-assisted process. Fourteen male Sprague-Dawley rats underwent implantation of either a standard or silver-coated double-cuff peritoneal catheter. Weekly observation and photographs documented exit-site characteristics. Erythema, exudate, loose fit, and poor hair growth were evidence of an inflamed exit. Overt infection was indicated by the presence of three or more of the following: erythema, purulent exudate, exuberant granulation tissue, loose fit, and poor hair growth. Animals were sacrificed at six weeks, and catheters were removed and processed for histology of the external tunnel. Multiple measurements were taken using a Filar eyepiece, and data were expressed as a mean of several readings. Inflammation, vascularity, and fibrosis were judged semiquantitatively. At the end of six weeks, six of the seven exits of the silver catheters showed excellent healing, while one exit site had signs of excessive inflammation. Four of the exit sites of the standard catheters healed well, two were inflamed, and one was overtly infected. The sinus tract of the standard and silver catheters had similar characteristics: keratinized and nonkeratinized epithelium lined the external part of the sinus tract and merged into granulation tissue. A fibrous sheath was noted in some sinus tracts between the granulation tissue and the cuff. The cuff evoked a foreign body reaction, with fibrosis, multiple giant cells, and vascularization. Poorly healing or infected sinus tracts had highly vascular granulation tissue with overlying exudate. The cuff of these catheters had marked inflammation and scanty giant cells, although collagen bundle thickness was similar to the well-healing catheters. In conclusion, silver-coating potentially enhances healing of the exit sites of peritoneal catheters. Additionally, the similarity of the tunnel histomorphology of standard and silver catheters confirms the favorable biocompatibility of silver.

Silver is known to have powerful antibacterial properties against a variety of micro-organisms and has a low toxicity and a favorable biocompatibility profile. This study was designed to evaluate the effectiveness of silver-coated catheters in preventing early exit-site infection and to assess tunnel morphology. Seven male Sprague-Dawley rats underwent simultaneous implantation of two double-cuffed, silver-coated silicone rubber and standard silicone rubber catheters. Weekly observations and photographs documented exit-site characteristics. The animals were sacrificed and catheters removed and processed for histopathology of the external tunnel at 5 weeks. Exit sites of silver-coated catheters tended to have less inflammation and infection and healed better than those of uncoated catheters; however, these data did not achieve significance using the Wilcoxon signed-rank test. Sections of the external tunnel of well-healing exit sites showed an epithelialized tract with granulation tissue near the cuff and significant invasion of the external cuff by collagen with a mild neutrophilic inflammatory response. In contrast, the histology of the external tunnel of infected exists revealed exudate overlying inflammatory granulation tissue and a variable degree of fibrosis of the cuff. When the exit sites appeared similar, no significant histopathological differences in sinus tract and cuff morphology were noted with either silver or standard catheters. In conclusion, these findings suggest that silver coating of catheters may decrease the incidence of early exit-site infections and allow better ingrowth of the catheter.

A computer interaction session conducted during the 14th Annual Peritoneal Dialysis Conference in Orlando, Florida, on January 24, 1994, revealed the preferences and practices of 650-690 respondents voting on questions related to peritoneal catheters. Compared to the surveys conducted in 1987 and 1989, the most striking change was an increase in the use of catheters with the bent intramural segment, particularly the Swan neck catheter, and an increase in the use of catheters with the coiled intraperitoneal segment. The Tenckhoff catheter continued to be the most popular, although its use was decreasing. The remaining catheters were used in small numbers. The vast majority of nephrologists remain convinced of the superiority of double cuff catheters over single cuff ones, and the use of the former continued to exceed 70%. Essentially no change occurred in the method of catheter placement; surgical dissection (72.7%) remained the most popular implantation method. Surgeons were primarily responsible for catheter implantations (87.4% of votes). The use of prophylactic antibiotics prior to catheter implantation seems to be increasing. The majority of respondents did not consider a Staphylococcus aureus nasal carrier status as important in the development of catheter-related infections, as indicated by the small number of centers where routine culture of nares was performed. The majority of institutions delayed ambulatory peritoneal dialysis after catheter implantation, but ambulatory peritoneal dialysis was started in some centers (5.7% of votes) in the immediate postimplantation period.

Over 700 people attending the Opening Session of the Fourteenth Annual Peritoneal Dialysis Conference participated in the computer interaction exercise as keyboard responders. Responders were 50.5% nurses and 40.4% physicians. Of these, 70.4% were from North America and 19.6% were from Europe. Only 9.5% had been involved in chronic peritoneal dialysis for less than one year. Over half (56%) worked in programs with more than 30 chronic peritoneal dialysis patients. Their own personal choice of dialysis therapy was a form of chronic peritoneal dialysis in 82%. Serum albumin concentration was indicated as the main monitor of nutritional status by 79.1%. Dietary protein intake ranging from 1-1.2 was considered the preferred goal by 84.4% of responders, even though the majority of chronic peritoneal dialysis patients probably do not achieve dietary protein intake in this range. A minimum weekly KT/V urea of 1.7 was chosen as a minimum target by 53.4%. An increase in exchange volume was the most frequently chosen approach to the large, anuric, low-peritoneal transporter. Numerous other questions dealing with adequacy and nutrition were posed to the audience, and the findings are summarized herein.