Peritoneal dialysis update 1994

Each year there are over 400 papers published in the field of peritoneal dialysis. In this review I have touched on only a few highlights of some of the more active areas of investigation and development. The advances in controlling peritonitis rates with the Y-set have been dramatic and have resulted in peritonitis rates in many centers less than one episode per 24 patient months. Technique survivals have also improved with lower peritonitis rates. The enormous literature on new approaches to treatment and new understandings of host defenses are beyond the scope of this review. There are also many advances in peritoneal access. We now have many new types of catheters under investigation such as the Swan-Neck Missouri catheter and the Moncrief-Popovich catheter, with complete burial of the catheter until eventual externalization for CAPD training. There have been major advances in understanding the normal healing of exit sites and the early diagnosis and treatment of exit-site infections. All the extensive literature on catheter development in the management of exit sites will be reviewed elsewhere. I have focused primarily on an update of worldwide demographics, some of the new findings in peritoneal transport, the use of low-calcium solutions, experiences with EPO, new thinking about adequacy and nutrition, and finally, on recent comparisons of CAPD and hemodialysis.     

Failure to cure Mycobacterium gordonae peritonitis associated with continuous ambulatory peritoneal dialysis

Nontuberculous mycobacteria are increasingly recognized as important pathogens in peritonitis associated with continuous ambulatory peritoneal dialysis (CAPD). Mycobacterium gordonae rarely causes human infection and is the least likely mycobacterium to produce clinical infection in CAPD patients. We describe a patient with persistent M. gordonae peritonitis acquired while undergoing CAPD. During 18 months of treatment, clinical improvement occurred but a microbiological cure could not be achieved. Principles of therapy for mycobacterial peritonitis developing during CAPD are reviewed, and potential explanations for our patient's failure to respond to therapy are discussed.     

Host defences in continuous ambulatory peritoneal dialysis and the genesis of peritonitis

Continuous ambulatory peritoneal dialysis (CAPD) has come to be extensively used for the treatment of end-stage renal failure in children, and especially infants, such that now more than half of children on dialysis worldwide receive treatment by this means. Peritonitis, however, is commoner in children than in adults receiving treatment, and is a major source of morbidity and treatment failure in children started on CAPD. Only recently has the immunology of the normal peritoneum been studied extensively, with the need to assess the impact of the installation of large volumes of fluid into the peritoneal sac during dialysis. The main phagocytic defences of the peritoneum depend upon a unique set of macrophages which are present free in the peritoneal fluid but also in the submesothelium and in perivascular collections together with B lymphocytes in the submesothelial area. Both the number of macrophages per unit volume and the concentration of opsonic proteins, such as IgG, complement and fibronectin, are reduced to between only 1% and 5% when dialysis fluid is continuously present in the peritoneal sac. In addition, the fluids used for CAPD are toxic to both macrophages and to mesothelial cells. Thus minor degrees of contamination frequently lead to peritonitis and in addition the majority of patients have catheters inserted in their peritoneum which become colonised with organisms capable of producing exopolysaccharide (slime), which promotes adhesion of the organism to the plastic and protects them against phagocytic attack and the penetration of antibiotics. Thus the peritoneum is in a state of continual inflammation, as well as being a markedly more vulnerable site than the normal peritoneum to the entry of organisms. Whether clinical peritonitis appears in this state of chronic contamination probably depends on perturbation in the balance between host defences and the organism. Whilst Staphylococcus epidermidis is the commonest cause of peritonitis, Staphylococcus aureus and Gram-negative organisms are much more serious and more frequently lead either to temporary catheter removal or discontinuation of dialysis altogether. This review describes the peritoneal defences in relation to the genesis of peritonitis.     

Comparative experience of a simple technique for laparoscopic chronic ambulatory peritoneal dialysis catheter placement

BACKGROUND: Chronic ambulatory peritoneal dialysis (CAPD) is now an established technique for renal dialysis. Patients with renal failure cope poorly with major surgery and it is vital that the dialysis catheter tip is sited accurately in the pelvis if long-term catheter function is to be achieved. Laparoscopic placement of CAPD catheters may have potential advantages for renal patients by avoiding the morbidity of a laparotomy. METHODS: A retrospective audit was performed of all CAPD catheters inserted at the John Hunter Hospital over a 2-year period. Results of laparoscopically inserted catheters and those placed at laparotomy were compared. RESULTS: Sixty catheters were inserted, 30 laparoscopically and 30 at laparotomy. The mean operative time was 41 min in the laparoscopic patients and 57 min in the laparotomy patients (P = 0.0001). The mean total dose of narcotic administered postoperatively was significantly less in the laparoscopic group (5 mg vs 65 mg, P = 0.00002). There were three minor peri-operative complications in the laparoscopic group and seven peri-operative complications in the laparotomy group, three required reoperation and one resulted in the patient's death. There were no significant differences in the incidence of exit-site infection, catheter blockage, peritonitis, and overall catheter survival, although the laparoscopically placed catheters had been followed up for a shorter period (10 vs 16 months). CONCLUSIONS: This laparoscopic technique is safe and effective. Postoperative pain was less than for open placement. Laparoscopically placed catheters had a low incidence of peri-operative complications. Medium-term patency is similar to conventionally placed catheters. This procedure requires no additional equipment to that available for laparoscopic cholecystectomy and takes less time than the open operation.     

Prevention of peritonitis with disconnect systems in CAPD: a randomized controlled trial. The Mexican Nephrology Collaborative Study Group

BACKGROUND: Recently, disconnect systems for CAPD that are associated with a reduced frequency of peritonitis have been introduced. Our objective was to compare the incidence of peritonitis using three current CAPD systems in a high-risk population with low educational and socioeconomic levels, and high prevalence of malnutrition. METHODS: In a prospective controlled trial, 147 patients commencing CAPD were randomly assigned to one of three groups: 29 to the conventional, 57 to the Y-set, and 61 to the twin bag systems. The number of peritonitis episodes was registered, and patients were followed up for an average of 11.3 months. RESULTS: The average peritonitis-free interval for the conventional group was 6.1 months, for the Y system was 12.0 months, and for the twin bag was 24.8 months (P < 0.001). By multivariate analysis, the only factor associated with peritonitis was the CAPD system. Peritonitis-related hospitalization was 5.3 +/- 2.0, 2.7 +/- 1.0, and 1.5 +/- 0.9 days/patient/year in the conventional, Y system, and twin bag groups, respectively. The cost per bag was similar for the conventional and Y system, but higher for the twin bag. However, the total costs of treatment (pesos/patient/year) were lower for twin bag (62,159 for the conventional, 70,275 for the Y system, and 54,387 for the twin bag), due to the lower peritonitis incidence and associated hospitalizations. CONCLUSIONS: Y system and twin bag use was associated with a reduction of 50 and 75% peritonitis incidence, respectively, in patients on CAPD. The cost of the twin bag was actually lower, because of savings from a decreased usage of antibiotics and fewer hospitalizations.     

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.     

Continuous ambulatory peritoneal dialysis--an effective method of treatment in chronic renal failure

The authors evaluate the results of treatment of continuous ambulatory peritoneal dialysis (CAPD) in seven patient with chronic renal failure during a 12-month period. The baseline examination was made one month before CAPD was started, one day before insertion of a Tenckhoff catheter and then after 1, 3, 6 and 12 months of treatment. The highest assessed mean serum urea concentrations during treatment were 19.8 +/- 2.3 mmol/l (arithmetic mean +/- SE of the mean), creatinine 815.1 +/- 43.1 mmol/l. The haematocrit improved significantly due to CAPD. From the mean value of 22.5 +/- 1.7% recorded one month before treatment it increased to 32.8 +/- 2.5% after 12 months of therapy. In five patients CAPD made it possible to discontinue and in two to reduce antihypertensive medication. During the investigation period the authors did not detect a drop of total protein and albumin in serum. Serum cholesterol increased significantly during treatment. Peritonitis was recorded four times during the total period of 70 months of treatment, i.e. on average one episode during 17.5 months of treatment. Based on their results the authors conclude that CAPD is at present one of the very effective methods of treatment of chronic renal failure. The incidence of peritonitis was already during the first year when treatment was initiated comparable with the results in departments where it is commonly used and after further experience it declined to one episode per 38.8 months of treatment. The method deserves wider application than hitherto.     

Interleukin-8 in chronic renal failure and dialysis patients

A total of 105 patients participated in this study, including 10 with chronic glomerulonephritis with normal renal function (CGN patients), 36 uraemic patients (CRF patients), 19 continuous ambulatory peritoneal dialysis patients (CAPD) without peritonitis, three CAPD patients with peritonitis, 37 patients undergoing chronic haemodialysis (HD) divided into short-term HD, 15 patients; medium-term HD, 12 patients; and long-term HD, 10 patients. IL-8 and two other proinflammatory cytokines, IL-6 and TNF alpha were tested using a specific immunoassay. IL-8, IL-6, and TNF alpha serum levels were significantly increased in patients with chronic renal failure compared to their levels in normal individuals (P < 0.0001, P < 0.05 and P < 0.0001 respectively). The most pronounced increment in IL-8, IL-6 and TNF alpha serum levels was observed in CAPD patients (P < 0.0001). CAPD patients without peritonitis showed relatively low levels of IL-8 or IL-6 in peritoneal dialysate effluents (PDE), whereas PDE-TNF alpha were not detectable in almost all patients tested. Patients with peritonitis showed very high serum and PDE levels of IL-8, IL-6 and TNF alpha. The clinical recovery from peritonitis was characterized by a rapid fall in IL-8, IL-6 and TNF alpha in serum and dialysate. HD patients showed a significant increase in serum levels of IL-8 and also IL-6 and TNF alpha compared to normal individuals (P < 0.05, P < 0.05 and P < 0.01 respectively).(ABSTRACT TRUNCATED AT 250 WORDS)     

Nystatin prophylaxis: its inability to prevent fungal peritonitis in patients on continuous ambulatory peritoneal dialysis

OBJECTIVE: To evaluate the potential effectiveness of nystatin as prophylaxis for fungal peritonitis (FP) in patients on continuous ambulatory peritoneal dialysis (CAPD). DESIGN: This historically controlled study was designed to investigate the effectiveness of nystatin in the prevention of FP. For this purpose we compared the incidence of FP among 240 (new and prevalent) CAPD patients between January 1996 and November 1996 (period A) with its incidence in 240 new and prevalent CAPD patients in our program between January 1997 and November 1997 (period B) when nystatin prophylaxis was used. There were 2400 patient-months in each period. Nystatin (500,000 IU four times per day), was given orally at the beginning of other antibiotic therapy (usually for peritonitis) and continued for 5 days after the end of the antibiotic therapy. RESULTS: During period A, 133 peritonitis episodes were recorded, and during period B, 99 episodes were recorded. Six episodes of FP were identified in over 2400 patient-months of period A, and 12 in over 2400 patient-months of period B. This difference was not statistically significant. Three episodes of antibiotic-related FP were seen in period A, and four in period B. The remaining episodes arose de novo, that is, unrelated to the use of antibiotics. We observed no side effects for nystatin. CONCLUSION: In CAPD patients the use of nystatin, a nonabsorbable antifungal agent, as prophylaxis in every instance of peritonitis or other indications for antibiotics, did not lower the incidence of fungal peritonitis.     

Simultaneous amoebic liver abscess and hepatitis A infection

Continuous ambulatory peritoneal dialysis (CAPD) is associated with various problems, including damage to the CAPD catheter. We encountered catheter rupture around the titanium adaptor in a patient who had been on CAPD for 7 years. The area near the adaptor generally suffers damage secondary to deterioration of the silicon composing the catheter. However, stereoscopic and electron microscopic observation of the surface of the catheter revealed no deterioration. Instead, there were fine scratches around the site of rupture and the broken surface was rough. Since the patient did not protect the catheter with gauze near the titanium adaptor, it was probably damaged by the adaptor and then ruptured by some external force.     

Charge selectivity of peritoneal transport in CAPD patients under stable states and during peritonitis

To investigate charge selectivity of peritoneal transport in CAPD, dialysate/plasma concentration ratios (D/P) were calculated for creatinine (Cr) and 3 amino acids with almost the same molecular weight but quite different charges: glutamic acid (Glu: negatively charged), glutamine (Gln: near neutrally charged) and lysine (Lys: positively charged). The study population consisted of 23 stable patients and 11 patients with peritonitis on CAPD. In the stable patients, the samples of dialysate were taken at 2 and 4 hours and blood samples were obtained at 4 hours after the infusion of 2 liters of 2.27 or 2.5% glucose CAPD dialysate; the samples of patients with peritonitis were obtained at 4.1 +/- 1.1 hours of dwell time. In stable patients, D/P of Glu was much lower than the values for Gln, Lys and Cr at both 2 and 4 hours (p < 0.01), and D/P of Lys was significantly lower than that of Gln (p < 0.01). There was no significant difference in D/P between Gln and Cr. In patients with peritonitis, D/P of Glu was also significantly lower than the values for Gln and Cr (p < 0.05 and p < 0.01), however, no significant differences were found between D/P of Lys and the values of Glu and Gln. Ratios of both [D/P Glu]/[D/P Lys] and [D/P Glu]/[D/P Gln] were much higher in peritonitis patients than in stable patients. In conclusion, peritoneal transport in stable CAPD patients shows charge selectivity, and the order of molecular charge for transperitoneal mobility among small solutes is neutral > positive > negative. The selectivity, however, is decreased or lost during peritonitis.     

Optimum electrode geometry for spinal cord stimulation: the narrow bipole and tripole

From a pathophysiological perspective, several studies have been performed on cytokines in chronic renal failure patients treated with continuous ambulatory peritoneal dialysis (CAPD). Because the peritoneal macrophages in CAPD patients produce some cytokines and the urinary secretion route for cytokines lost in those patients, CAPD patients are considered to have different plasma cytokine levels. Among the various cytokines, research on certain inflammatory cytokine levels has been reported. In studies of CAPD patients, peripheral blood and dialysate can be used as specimens. There are two methods of research. One involves determining the cytokine concentration in specimens and culture supernatant, while the other is to determine the mRNA expression of mononuclear cells in specimens and cultured mononuclear cells. The plasma levels of macrophage colony stimulating factor (M-CSF), granulocyte macrophage colony stimulating factor (GM-CSF) and granulocyte colony-stimulating factor (G-CSF) were measured in CAPD patients without peritonitis. Plasma M CSF, GM CSF and G-CSF levels in CAPD patients were higher than those in healthy volunteers (p < 0.0001).     

Peritonitis in continuous ambulatory peritoneal dialysis. Culture of peritoneal dialysate fluid

Conventional aerobic and anaerobic culture of peritoneal dialysate effluent from patients in continuous peritoneal dialysis (CAPD) was compared to culture in a semiautomated blood culture system. During a two-year period 78 of 79 consecutive episodes of peritonitis among 45 Danish CAPD patients were cultured and the etiology of the infection found in 73 (94%). The sensitivity of the blood culture system was 88%, whereas the sensitivity of the conventional culture of the dialysate effluent was 81%. This difference is not significant (McNemar test; 0.5 > p > 0.3). The majority of isolates were Gram-positive bacteria dominated by coagulase-negative staphylococci (38%). In comparison, only 2% of the cultures of peritoneal dialysate effluent taken within the same period from patients without clinical signs of peritonitis were positive. All the Gram-positive aerobic bacteria were sensitive to vancomycin whereas 97% of the Gram-negative aerobic bacteria were sensitive to gentamicin. An initial empiric treatment of peritonitis with a combination of vancomycin and gentamicin is recommended.     

Interleukin-10, interferon gamma, interleukin-2, and soluble interleukin-2 receptor alpha detected during peritonitis in the dialysate and serum of patients on continuous ambulatory peritoneal dialysis

OBJECTIVE: To analyze interleukin (IL)-10, interferon gamma (IFN-gamma), IL-2, and soluble IL-2 receptor alpha (sIL-2R alpha) in the dialysate and serum of patients on continuous ambulatory peritoneal dialysis (CAPD). DESIGN AND PATIENTS: Samples from dialysate bags were collected during the initial month of dialysis. During peritonitis, samples were collected from the first three bags on the day of admittance to the hospital and from the night bags on days 3 and 10. Serum samples were drawn on days 1 and 10. RESULTS: IL-10 was detected in all dialysate samples except one on the first day of infection, with a peak median level of 50 pg/mL and a slow decrease thereafter. In serum the median levels never exceeded detectable levels. Patients infected with Escherichia coli or Staphylococcus aureus had higher IL-10 levels in dialysate on day 3 as compared to the remaining patients (p < 0.05). If the catheter had to be drawn, because of persistent cloudy dialysate, the IL-10 levels remained elevated for a longer time (p < 0.05). IFN-gamma and IL-2 were detected only in the dialysate of patients infected with either S. aureus or S. epidermidis. Only one serum sample showed increased IFN-gamma. SIL-2R alpha was found in all the serum and dialysis samples from the first day of infection. Contrary to the analyzed cytokines, the receptor showed severalfold higher levels in serum as compared to the dialysate. During the infection the receptor levels in the dialysate increased, while they remained stationary in the serum, indicating a local production. CONCLUSION: This is the first time IL-10 has been demonstrated in the dialysate during peritonitis in CAPD patients. In view of its role as a suppressor of the immune and inflammatory responses, it is a potentially important observation, which might have clinical implications in the future.     

Schizophrenia, schizophrenia-like disorders and delusional disorders in patients with anorexia nervosa: literature review and report of 3 cases

This study compared specific phenotypic and potential virulence characteristics of Staphylococcus aureus isolates from invasive infections and nasal carriers. Three hundred and sixty isolates were studied; 154 from septicaemia (69 line associated, 85 non-line), 79 from continuous ambulatory peritoneal dialysis (CAPD) peritonitis, 64 from bone/joint infections and 64 from healthy nasal carriers. The isolates were tested for production of enterotoxins (SE) A, B, C or E, toxic shock syndrome toxin-1 (TSST-1) protein A, and also for lipolytic, proteolytic, fibrinolytic and haemolytic activities. In addition phage typing, crystal violet reaction, urease and galactose breakdown were studied. Seventy-one percent of isolates were enterotoxigenic. Production of SEA was significantly lower amongst the bone/joint isolates. Production of SEB, was lower among the control group compared with CAPD, bone/joint, and non-line septicaemia isolates. SEE production was higher among the bone/joint isolates compared with the CAPD and non-line septicaemias and production of TSST-1 was significantly higher among nasal isolates compared with isolates causing infection. Almost all of the isolates were lipolytic, with highest activity amongst nasal and bone/joint isolates. Fibrinolytic activity was similar in the five groups of isolates. Proteolytic activity ranged from 35 to 62% of isolates with the lowest frequency among septicaemia isolates. In all, 80-90% of isolates were haemolytic, although CAPD isolates were less likely to be haemolytic. Isolates from the control and CAPD group more frequently belonged to phage group I. TSST-1 does not appear to be an important requirement for invasive infections, but SEB may be. Proteolysis and intensity of lipolysis appear to be less important in septicaemia, and haemolysis may not be important in CAPD peritonitis.     

NT/3M National Nursing Awards. Crisis management

The increasing number of patients on CAPD (continuous ambulatory peritoneal dialysis) offers multiple challenges to the home dialysis unit. During the last year we have changed our nursing practice and have successfully trained five visually impaired clients to perform CAPD exchanges utilizing a disconnect system without a helper or caregiver. In this article we will discuss the methods we used, the assist devices and the patient outcomes in our population. We measured our success in terms of peritonitis rate, adequacy of dialysis and lifestyle considerations for this population.     

Sonographic determination of the thickness of the peritoneum in healthy children and paediatric patients on CAPD

BACKGROUND: Prolonged peritoneal dialysis and frequent episodes of peritonitis lead to structural changes and thickening of the peritoneum. Ultrasonography investigations may provide the opportunity to detect morphological changes early, but no systematic investigations have been performed yet. METHODS: Normal values of peritoneal thickness were obtained by systematically examining 131 healthy children (0-15 years) by ultrasound. Parietal peritoneal thickness was best measured at the sternal-umbical line distal from the xiphoid. Growth charts with 95% intervals were prepared. The data of 26 patients with end-stage renal failure (5-18 years) were compared to those of the normal children. RESULTS: The variation coefficient for the consecutive measurements was only 5%, interobserver error was approximately 7%. Whereas gender did not have any influence, peritoneal thickness was significantly correlated to age, weight and most obviously to height (r = 0.81; P<0.001). Children treated only by haemodialysis had normal values, while an increased thickness, loss of movement, and adhesion of the two peritoneal layers were found in children on CAPD. These changes were only noted in patients who had a history of peritonitis. CONCLUSION: Ultrasound examination is a simple, noninvasive and precise method to measure the peritoneal changes in children on CAPD.     

Clinical experience of automated peritoneal dialysis

For uremic patients on continuous ambulatory peritoneal dialysis who are complicated with peritonitis, hernia or burn out of meticulous procedure, automated peritoneal dialysis (APD) is a new alternative therapy. We started our APD program by continuous cyclic peritoneal dialysis (CCPD) method from October, 1991 and this study included 3 CAPD patients. Our studies showed high dose CCPD was better than CAPD in ultrafiltration and urea clearance with similar weekly creatinine clearance and weekly KT/V urea. During the one year treatment course, there was no signs of fluid overload. We performed once to twice day time exchange by low volume dialysate (1500-1600ml) There was no events of abdomen discomfort due to increase intraabdominal pressure or recurrent hernia in susceptible patient. The decrease in day time exchange frequency obviously reduced patients'loading. One patient changed to high dose CCPD due to underdialysis after stand CCPD therapy. Two patients returned to hemodialysis due to severe peritonitis and technique method, but careful assessment of dialysis adequacy with PET test and KT/V evaluation is mandatory.     

Icodextrin use in CCPD patients during peritonitis: ultrafiltration and serum disaccharide concentrations

BACKGROUND AND METHODS: In a randomized study on the biocompatibility of icodextrin (I) versus glucose (G) in CCPD we used icodextrin or glucose for the long daytime dwell. During the night-time dwells glucose was used in all patients. In case of peritonitis icodextrin was continued. In all patients ultrafiltration (UF) was recorded and serum icodextrin metabolites were determined every 3 months and during peritonitis in I-users when available. RESULTS: Thirty-eight patients ( 19 G, 19 I) entered the study and suffered 30 peritonitis episodes (16 G, 14 I). During peritonitis (P), daytime dwell UF decreased significantly in G (P=0.001), but remained stable in I patients compared to non-peritonitis (NP) episodes. Total 24-h UF decreased in G (P=0.001) and in I patients (P=0.04), as the result of a decreased daytime UF and night-time UF, respectively. There was no difference in the used glucose concentrations during the P versus NP episodes. In five I-patients serum disaccharides increased from 0.05+/-0.01 to 1.26+/-0.23mg/ml during follow up. During peritonitis serum disaccharide concentrations did not increase further (1.47+/-0.24 mg/ml, P= 0.56). In I patients total carbohydrate minus glucose rose to 5.72 +/- 1.2 mg/ml during follow up, and to 6.63 +/- 1.04 mg/ml during peritonitis (P=0.7). These concentrations are comparable to CAPD patients despite the longer dwelltime in CCPD (8-10 versus 14-16 h, respectively). Adverse reactions attributable to icodextrin were not encountered. CONCLUSIONS: In contrast to glucose, icodextrin preserved the daytime dwell ultrafiltration during peritonitis. Serum icodextrin metabolites increased during icodextrin use, but remained stable during peritonitis. Adverse effects were not observed.