Activity of some lysosomal enzymes in peritoneal macrophages of patients with end-stage renal failure treated by intermittent peritoneal dialysis.

Acid phosphatase, beta-D-Glucuronidase and N-acetyl-beta-D-glucosaminidase were assessed cytochemically in peritoneal macrophages obtained from 50 patients with end-stage renal failure treated by intermittent peritoneal dialysis and from 30 control subjects with normal renal function. A statistically significant increase in beta-D-glucuronidase activity accompanied by a decrease in acid phosphatase activity were observed in peritoneal macrophages of dialysed patients, as compared with the control group. In patients with dialysis-associated peritonitis, the activity of N-acetyl-beta-D-glucosaminidase was significantly higher than that observed in the same patients during the complication-free period of the treatment.     

The ultrastructure of the peritoneal membrane in chronically dialysed rats with spontaneous peritonitis: preliminary observations

In this paper we describe ultrastructure of the peritoneal membrane from single peritoneal biopsies collected from chronically dialysed rats with spontaneous peritonitis. The results were compared with those obtained in chronically dialysed animals without peritonitis. In rats with peritonitis, peritoneum was much thicker than in peritonitis-free animals. The increased thickness of the peritoneum during peritonitis was due to infiltration of the submesothelial tissue with oedematous fluid and to the presence of huge amount of cells in the stroma. The connective tissue cells were accumulated just underneath the peritoneal surface. In deeper parts of the interstitium, infiltrating acute inflammatory cells were present (lymphocytes, polymorphonuclear cells: neutrophils and eosinophils). Inversely, the increased thickness of the peritoneum in peritonitis-free animals was mainly due to enhanced amounts of collagen. Additionally, in rats with peritonitis, the surface was often denuded of mesothelial cells. The damaged mesothelial cells that detached from the peritoneal surface were also found. In conclusion, the morphological changes observed in rats with peritonitis are similar to those reported in humans, thus the model of peritonitis in dialysed rats can be used for the study of peritoneal remodeling during peritoneal dialysis complicated by peritonitis.     

Phagocytosis and neutrophil bactericidal capacity in patients with uremia

The phagocytic activity and bactericidal capacity of polymorphonuclear neutrophils (PMN) were evaluated in patients with advanced chronic renal failure. The studies were made in patients undergoing hemodialysis, maintenance peritoneal dialysis as well as in nondialysed patients. Evaluations were carried out by using of the recently described fluorochrome microassay which enabled these parameters to be estimate independently. The phagocytic activity was seriously diminished in nondialysed patients, whereas it was similar to controls in those hemodialysed and undergoing peritoneal dialysis patients. In all evaluated groups of patients the bactericidal capacity was significantly reduced. The lowest values could always be observed in nondialysed patients. The decrease of bactericidal capacity was significantly more evident in patients undergoing peritoneal dialysis as compared with those hemodialysed. The obtained results confirm some previous reports suggesting the impairment of PMN function in uremic patients. This results in their increased susceptibility to infection. They also reveal the existence of a close relationship between the extent of observed dysfunctions and the management applied.     

Acute and chronic influence of hemodialysis according to the membrane used on phagocytic function of neutrophils and monocytes and pro-inflammatory cytokines production in chronic renal failure patients

This work evaluated the phagocytic capacity of monocytes and neutrophils, and tumor necrosis factor-alpha, interleukin 6, 1 and 8 serum levels in chronic renal failure patients under peritoneal dialysis and hemodialysis treatment, compared with chronic renal failure patients without dialysis treatment and healthy individuals, in order to contribute to a better understanding of the action of these therapies on the evolution of chronic renal failure patients. All patients with chronic renal failure (under dialysis or not) showed decreased phagocytic capacity of neutrophils and monocytes. All those in hemodialysis (cellulose acetate or polysulfone membranes) showed a decreased phagocytic capacity. The phagocytic index for neutrophil was 13 times lower than that of the control group for both membranes, whereas for monocytes, only those using polysulfone membrane showed a significant decrease of 4.9 times in phagocytic capacity. There was an acute stimulation of the phagocytosis by neutrophils after a single session of dialysis with both types of membrane, while only cellulose acetate membrane decreased the phagocytic index of monocytes after the hemodialysis session. Patients using cellulose acetate showed a chronic increase in tumor necrosis factor-alpha serum levels, while those using polysulfone showed a chronic increase in interleukin 6. After a single hemodialysis procedure, no acute effect of the treatment on tumor necrosis factor-alpha and interleukin 6 levels was identified. The decreased phagocytic function of neutrophils and monocytes may account for the high levels of susceptibility of chronic renal failure patients to infections with pyogenic bacteria and tuberculosis. Furthermore, inflammatory activity may occur with both types of membrane studied, suggesting that it will be useful for these patients to evaluate some anti-inflammatory or anti-cytokine therapies against tumor necrosis factor-alpha and interleukin 6, in order to avoid cardiovascular complication.     

The ultrastructure of the peritoneal membrane in chronically dialysed rats

The model to estimate peritoneal function in chronically dialysed rats was previously presented by us. The aim of the paper is to report the findings obtained in electron microscopy of peritoneal biopsies from Wistar rats dialysed for 1 month with high glucose dialysis solution. In control animals, thin mesothelial cells were covered with microvilli. The submesothelial tissue was composed of sparse bundles of parallelly oriented collagen fibers with a few resting cells. In chronically dialysed rats, mesothelial cell layer was thicker and cells were fully packed with intracellular structures, mainly secretory granules with a homogeneous content. The submesothelial tissue was expanded due to the increased amount of collagen fibers, oedema and increased amount of submesothelial cells which were activated. The use of electron microscopy to study the peritoneum in dialysed rats is an excellent supplement to the chronic functional model of peritoneal dialysis in rats.     

Factors affecting development of peritonitis in continuous ambulatory peritoneal dialysis.

A questionnaire based survey in patients receiving continuous ambulatory peritoneal dialysis showed that there was an increased incidence of upper respiratory tract symptoms (suggestive of viral illness) in the 14 days before the development of peritonitis. No other factors were identified that might distinguish patients who develop peritonitis. The possibility that viral infections predispose to peritonitis by altering host defence mechanisms in patients receiving this form of renal replacement therapy warrants further study.     

Continuous ambulatory peritoneal dialysis and renal transplantation: a five year experience.

Continuous ambulatory peritoneal dialysis is a new and increasingly popular method of routine dialysis, but its effect on renal transplantation is uncertain. A non-randomised comparison was made of the outcome of grafting in patients who had been treated before transplantation with continuous ambulatory peritoneal dialysis with that in patients treated with haemodialysis. During the five years, 1979-84, after continuous ambulatory peritoneal dialysis was introduced to Newcastle upon Tyne 220 patients have received transplants after either continuous ambulatory peritoneal dialysis (61 patients) or haemodialysis (159 patients). During follow up no significant differences occurred in survival of patients or grafts between the two treatment groups. One year after transplantation the percentages of survivors who had received continuous ambulatory peritoneal dialysis and haemodialysis were 88% and 91% respectively, and overall graft survival was 66% and 72%, respectively. A multiple regression model was used to allow for differences among patients--for example, duration of dialysis and number of preoperative transfusions--on the survival of grafts. When only first cadaver grafts were considered (in 152 patients) graft survival (non-immunological failures excluded) was not significantly different between the patients treated with continuous ambulatory peritoneal dialysis and haemodialysis. Continuous ambulatory peritoneal dialysis is not a risk factor in renal transplantation, and its continued use in treatment of potential renal graft recipients is recommended.     

The permanent Tenckhoff catheter for chronic peritoneal dialysis.

Over a 3 1/2-year period the permanent Tenckhoff catheter was used in 66 patients (32 men and 34 women) maintained on chronic peritoneal dialysis for periods from 2 1/2 to 36 1/2 months; 57 patients had dialysis in hospital for 20 to 24 hours twice a week and the other 9 had dialysis at home for 10 to 12 hours four times a week. While the Tenckhoff catheter was in place 14 patients received a renal transplant; for 13 who required peritoneal dialysis during the post-transplant phase the Tenckhoff catheter was used. In nine patients abdominal surgery did not interfere with the continuation of peritoneal dialysis via the Tenckhoff catheter. From a total of 5067 dialyses 40 positive cultures were reported (0.8%). Peritonitis was clinically evident on only 14 occasions (0.28%). Permanent catheter obstruction developed in 16 patients, in 11 of whom it was related to peritonitis. With the introduction of the permanent Tenckhoff catheter long-term peritoneal dialysis has become a simple, safe and painless procedure, suitable for virtually all patients who require maintenance dialysis.     

Evaluation of loss of active heparin in the peritoneal cavity during intermittent peritoneal dialysis]

Our studies aimed at determining a loss of active heparin from the peritoneal cavity after its intraperitoneal administration (250 JU/l of dialysis fluid) in 16 patients treated because of the end-stage renal failure with intermittent peritoneal dialysis and at comparing heparin influx clearance with that of glucose. It has been shown that heparin used in this dose loses 60-70% of its activity after 20-minute equilibration of dialysis fluid in the peritoneal cavity. Heparin influx clearance is higher than that of glucose but it depends on utilization of heparin in peritoneal cavity rather than on its penetration to the blood circulation.     

维持性腹膜透析患者并发真菌性腹膜炎的易感因素和结局分析

目的分析腹膜透析相关性真菌性腹膜炎(FP)发生率、致病菌、治疗情况和预后。方法回顾性分析2010年1月至2019年10月陆军军医大学第二附属医院腹膜透析中心发生的18例FP,选择与同期收治非真菌性腹膜炎113例比较,记录所有FP患者的临床资料,治疗方法和转归,分析FP发生的易感因素和结局。结果腹膜透析相关性腹膜炎共389例次,FP 18例次,占4.6%。其中白念珠菌6例(33.3%)、近平滑念珠菌5例(27.8%)、无名念珠菌3例(16.7%)、光滑念珠菌2例(11.1%)、热带念珠菌1例(5.6%)和克柔念珠菌(5.6%)1例。与非真菌性腹膜炎相比较,FP组腹透时间更长(P<0.001)、既往抗生素使用率高(P<0.001)、血浆白蛋白(ALB)更低(P<0.001)、C反应蛋白(CRP)更高(P<0.001)、甲状旁腺激素(PTH)和血磷(P)水平更高(P<0.001)。Logistic回归分析结果显示腹透时间越长、1个月内使用抗生素、低ALB和高CRP是发生FP的危险因素(P<0.05)。18例次FP中,14例患者拔管转血透(77.8%),4例患者死亡(22.2%),FP组腹膜透析技术失败率和死亡率明显高于BP组。结论腹透时间越长、既往使用抗生素、低ALB和高CRP是FP的易感因素。FP是腹膜透析的严重并发症,是导致技术失败的主要原因,确诊后早期拔管可降低死亡率。     

Renal transplantation in patients treated with haemodialysis and short term and long term continuous ambulatory peritoneal dialysis.

Forty two adult patients who had been treated with continuous ambulatory peritoneal dialysis for one to 142 weeks (mean (SD) 38 (36)) received a total of 44 allografted kidneys. Twenty one had been treated with continuous ambulatory peritoneal dialysis for less than 26 weeks (mean 11 (8)) and the other 21 for longer than 26 weeks (mean 64 (35)). These two groups were compared with 55 patients who had been treated with haemodialysis and received a total of 63 grafts. In the group of patients treated with continuous ambulatory peritoneal dialysis azathioprine and low dose prednisolone were used as the immunosuppressive regimen for 20 transplantations in 18 patients, and 24 patients receiving 24 grafts were treated with cyclosporin A and low dose prednisolone. In the group of patients treated with haemodialysis 38 patients receiving 43 grafts were treated with azathioprine and low dose prednisolone, and 20 patients receiving 20 grafts were treated with cyclosporin A and low dose prednisolone. Actuarial survival of patients and grafts at two years was 95% and 72%, respectively, in the continuous ambulatory peritoneal dialysis group compared with 89% and 58%, respectively, in the haemodialysis group. No difference was found in graft survival between short term treatment with continuous ambulatory peritoneal dialysis (72% graft survival) and long term treatment (65% graft survival). In conclusion, continuous ambulatory peritoneal dialysis is suitable treatment for patients awaiting renal transplantation.     

Potential use of tuftsin in treatment of candida peritonitis in a murine model

A major complication of continuous ambulatory peritoneal dialysis (CAPD) is peritonitis caused by Candida albicans. Increasing the activity of the peritoneal macrophages, the predominant cell type found in the peritoneal cavity, may be a promising treatment for this infection. Tuftsin was found to increase thioglycollate-elicited mouse peritoneal macrophage activity. 2x10(-7) M tuftsin enhanced two-fold cell association with radiolabelled candida, superoxide aniom production, and killing activity. Thus, a model consisting of mice undergoing peritoneal dialysis was developed in order to study the use of tuftsin as a therapeutic drug against peritoneal candidiasis. Administration of tuftsin (50 micrograms/mouse) before candidiasis induction with a lethal dose of candida (7x10(8) candida per mouse) improved mouse survival up to 70%, compared with 10% in the control group. The potential of tuftsin as a treatment for candidiasis was shown when the infection was induced with a sublethal dose of candida. Daily intraperitoneal injections of tuftsin (50 micrograms) to the sublethally infected mice caused a significant decrease in the number of candida recovered from the peritoneal cavity and from the blood (from 700 +/- 190 to 110 +/- 26 CFU/ml and from 100 +/- 26 CFU/ml to 17 +/- 8 CFU/ml, respectively). In addition, a larger number of peritoneal macrophages with greater phagocytic and killing activity were found in the tuftsin-treated mice. The effect of tuftsin may promote its potential use in the therapy of peritonitis in patients undergoing chronic peritoneal dialysis.     

Bactericidal activity of human peritoneal macrophages from patients undergoing peritoneal dialysis

Peritoneal macrophages (PM) play an essential role in the pathogenesis of bacterial peritonitis, the main complication of peritoneal dialysis (PD). We determined the antibacterial activity of PM from 31 PD patients using gram-positive (Staphylococcus aureus, Staphylococcus epidermidis) and gram-negative (Escherichia coli, Pseudomonas aeruginosa) test organisms. In an 8-hour test assay, PM revealed the highest antibacterial activity against E. coli [median bactericidal index (Bi) = 5.46 representing 0.74 log growth inhibition compared to controls] and the lowest against P. aeruginosa (Bi = 1.63, 0.21 log growth inhibition, p less than 0.05). The antibacterial activity against S. aureus (Bi = 1.99, 0.3 log growth inhibition) and S. epidermidis (Bi = 2.0, 0.31 log growth inhibition) was within this range. When compared to peripheral blood polymorphonuclear leukocytes, PM reached only 4% (S. aureus) and 8.1% (E. coli) of their antibacterial activity (p less than 0.05). Using E. coli as a test organism, PM isolated after a 4-hour dialysis period revealed the highest antibacterial activity when compared to PM isolated after longer dialysis periods (p less than 0.05). Increasing the duration of PD to 6 and 8 h subsequently decreased the antibacterial activity of PM, suggesting that unphysiologic concentrations of toxic metabolites in the peritoneal effluent might have a harmful influence on PM functions.     

Use of the Deane prosthesis in patients on long-term peritoneal dialysis

The Deane peritoneal prosthesis has been used successfully in the treatment of 21 patients with chronic renal failure who were maintained on peritoneal dialysis for periods of up to 20 months. All patients were dialyzed for 24 hours twice weekly. While the prosthesis was still in place, transplantation was carried out in seven patients and laparotomy in three. The prosthesis was also used temporarily whenever a permanent peritoneal catheter (Tenckhoff''s) failed because of infection; it was used until the signs of infection disappeared, then the permanent catheter could be replaced safely. From a total of 1136 dialyses 36 positive cultures were reported. Clinical peritonitis was found on only four occasions.     

Morphological and phagocytic characteristics of peritoneal exudate cells in tilapia, Oreochromis niloticus (Trewavas), and carp, Cyprinus carpio L.

The morphology and phagocytic activity of peritoneal exudate cells (PEC) obtained by an intraperitoneal injection of liquid paraffin into tilapia, Oreochromis niloticus , and carp, Cyprinus carpio , were studied with light and electron microscopy. PEC consisted of monocyte-macrophage series cells (M-Mø), neutrophils, eosinophils (granular cells) and others. Cells exhibiting the same morphology as mammalian macrophages but different from monocytes of the same species were identified with light and electron microscopy and designated as peritoneal macrophages. Light and electron microscopy revealed that M-Mø, neutrophils and eosinophils (granular cells) phagocytozed foreign materials added in vivo and in vitro. Eosinophils appeared later in the peritoneal exudate and less actively phagocytic as compared with M-Mø and neutrophils. Small and large phagosomes were formed in M-Mø, neutrophils and eosinophils (granular cells). Large phagosomes were common in neutrophils. Fusion of cytoplasmic granules with the phagosome membrane was observed. The in vitro experiment on phagocytosis revealed that the phagocytic rates in M-Mø and neutrophils were positively correlated with the doses of foreign materials. The results indicated that these two cell types have the highest capacity of phagocytosis.     

Adverse outcomes among Aboriginal patients receiving peritoneal dialysis

Background

The Aboriginal population in Canada experiences high rates of end-stage renal disease and need for dialytic therapies. Our objective was to examine rates of mortality, technique failure and peritonitis among adult aboriginal patients receiving peritoneal dialysis in the province of Manitoba. We also aimed to explore whether differences in these rates may be accounted for by location of residence (i.e., urban versus rural).

Methods

We included all adult patients residing in the province of Manitoba who received peritoneal dialysis during the period from 1997–2007 (n = 727). We extracted data from a local administrative database and from the Canadian Organ Replacement Registry and the Peritonitis Organism Exit-sites/Tunnel infections (POET) database. We used Cox and logistic regression models to determine the relationship between outcomes and Aboriginal ethnicity. We performed Kaplan–Meier analyses to examine the relationship between outcomes and urban (i.e., 50 km or less from the primary dialysis centre in Winnipeg) versus rural (i.e., more than 50 km from the centre) residency among patients who were aboriginal.

Results

One hundred sixty-one Aboriginal and 566 non-Aboriginal patients were included in the analyses. Adjusted hazard ratios for mortality (HR 1.476, CI 1.073–2.030) and adjusted time to peritonitis (HR 1.785, CI 1.352–2.357) were significantly higher among Aboriginal patients than among non-Aboriginal patients. We found no significant differences in mortality, technique failure or peritonitis between urban- or rural-residing Aboriginal patients.

Interpretation

Compared with non-Aboriginal patients receiving peritoneal dialysis, Aboriginal patients receiving peritoneal dialysis had higher mortality and faster time to peritonitis independent of comorbidities and demographic characteristics. This effect was not influenced by place of residence, whether rural or urban.The Canadian Aboriginal population suffers from a high burden of illness,^1,2 low socio-economic status and geographic isolation.³ A high prevalence of diabetes mellitus, obesity and hypertension in this population is resulting in rapid growth in rates of kidney disease and renal failure (i.e., end-stage renal disease).^4–6 The escalation in demand for dialytic services and care of patients with end-stage renal disease care will require appropriate planning and allocation of health care resources.Hemodialysis is resource-intensive and requires residence in proximity to a dialysis centre. In Canada, roughly 18% of all dialysis patients are receiving peritoneal dialysis.⁷ These patients are responsible for their own dialysis therapy and are seen periodically in an ambulatory clinic setting. No clear mortality-related benefit is associated with choice in modality of dialysis; each method has its own risks and benefits.^8–10 Complications of peritoneal dialysis include technique failure, which often requires conversion to hemodialysis and relocation of the patient, and peritonitis.Dosage of peritoneal dialysis is determined by the combined clearance of solutes from the peritoneum (termed the peritoneal Kt/V) and, if applicable, by residual renal function (termed renal Kt/V). The peritoneal equilibration test is a marker of the peritoneal membranes solute transport characteristics and high peritoneal equilibration test values have been associated with inflammation, volume overload, technique failure and mortality.¹¹Compared with non-Aboriginal patients who have end-stage renal disease, Aboriginal patients with end-stage renal disease are younger on average and more likely to reside in geographically remote locations.¹² Use of home-based dialysis modalities, such as peritoneal dialysis, would be well suited to this population because it allows patients to continue to live in their communities. However, residing far from a dialysis centre or a patient’s primary nephrologist is associated with increased mortality, poor compliance and impaired quality of life.^12,13 Previous studies have found that Aboriginal patients receiving peritoneal dialysis have similar mortality and rates of technique failure to patients of other ethnicities. But whether this is true in a contemporary cohort is not known.^14,15Our objective was to examine differences in mortality and in rates of technique failure and peritonitis among Aboriginal patients versus non-Aboriginal patients receiving peritoneal dialysis and to explore whether differences may be accounted for by urban versus rural residence.     

Continuous ambulatory peritoneal dialysis after the honeymoon: review of experience in Newcastle 1979-84.

Two hundred and twenty nine consecutive patients (129 men, mean age 45) were reviewed 12 to 65 months after starting treatment with continuous ambulatory peritoneal dialysis (CAPD) from January 1979 to December 1983. They received CAPD for a mean of 19.8 (range 0.5-62) months. Actuarial patient survival was 79% at 24 months and 72% at 36 months. Half of the 46 deaths were related to cardiovascular disease, while eight patients died of abdominal complications, including three patients with peritonitis. Peritonitis occurred at a rate of one episode per 35 patient weeks, and 88% of episodes were cleared by one or more courses of antibiotics. This still left peritonitis as the commonest cause of failure of CAPD, leading to a permanent change of treatment in 44 patients and temporary interruption in a further 25. CAPD remains a reasonable medium term treatment in chronic renal failure. Despite the persisting problem of peritonitis the results are comparable with those achieved by haemodialysis, and CAPD has become the treatment of first choice for end stage renal failure in Newcastle. In younger patients judged unsuitable for transplantation and facing long term dialysis, however, haemodialysis is preferred.     

Impact of continuous ambulatory peritoneal dialysis on treatment of renal failure in patients aged over 60.

Thirty eight patients aged over 60 with end stage renal disease were treated by continuous ambulatory peritoneal dialysis for up to three years. Most of these patients, because of their age or coexisting diseases, had been considered to be unsuitable for haemodialysis by the criteria used before the advent of continuous ambulatory peritoneal dialysis in 1980. Actuarial patient survival at one and two years was 72% and 61% respectively, and only two patients were permanently transferred to haemodialysis. Twenty one of the 23 survivors were fully rehabilitated, the remaining two being partially disabled but living at home. Continuous ambulatory peritoneal dialysis permits more liberal selection of patients with end stage renal disease for renal replacement treatment with excellent survival and rehabilitation and without overburdening scarce hospital haemodialysis facilities.     

The professional phagocytes of sea bass (Dicentrarchus labrax L.): cytochemical characterisation of neutrophils and macrophages in the normal and inflamed peritoneal cavity

In order to identify the phagocytic cells of sea bass, the peritoneal leucocyte population of fish injected intraperitoneally with Photobacterium damselae subspecies piscicida was studied by light microscopy using cytocentrifuge preparations stained by the Antonow technique for peroxidase detection. Among the leucocytes present in the peritoneal exudate of the infected fish (macrophages, neutrophils, eosinophilic granular cells, lymphocytes and thrombocytes), macrophages and neutrophils were the only phagocytic cells. Neutrophils were easily distinguished from macrophages in Antonow stained preparations by the pattern of peroxidase positivity. Using ultrastructural cytochemistry, neutrophils were found to have abundant cytoplasmic granules positive for peroxidase and arylsulphatase and were negative for alpha-naphthyl butyrate (ANB) esterase. In contrast, ANB esterase activity was detected in macrophages. These leucocytes were typically negative for peroxidase, but ocasionally, some macrophages with peroxidase or arylsulphatase-positive vacuoles were observed. Both phagocytes had cytoplasmic granules positive for acid phosphatase. Glycogen particles were found in the cytoplasm of the two phagocytic cells, but they were much more abundant in neutrophils. Macrophages were much more abundant than neutrophils in the peritoneal cavity of non-injected sea bass but early after the intraperitoneal injection of bacteria, the number of neutrophils increased quickly and extensively. Higher numbers of intraperitoneally injected bacteria were found inside macrophages as compared to neutrophils because macrophages strongly predominated in the peritoneal population at the time of injection. However, when the bacteria were injected into peritoneal cavities with high numbers of neutrophils (attracted by a previous injection of 12% casein), the percentage of neutrophils with phagocytosed bacteria increased, approaching that of infected macrophages. Taken together, these results show that in sea bass, as in many other organisms, in addition to macrophages, neutrophils are important phagocytic cells, the relative participation of each of the two phagocytes in defense mechanisms against infection depending on the opportunity to encounter the invading infectious agents.     

Peritonitis prevented in continuous ambulatory peritoneal dialysis by using the Hong Kong connection.

Based on the hypothesis that air contamination is an important cause of peritonitis in continuous ambulatory peritoneal dialysis, a simple and cheap connection system was developed whereby a clear polyethylene bag containing an antiseptic gauze was used as a sterilising chamber, effectively enclosing the connection procedure. Seven modifications to the connection technique were introduced over 32 months in 28 patients during 27.9 patient years of experience. The overall rate of peritonitis was 0.6 episode/patient year, but after a final modification at the beginning of the third year the rate fell to 0.17, without a single case of peritonitis occurring attributable to a connection failure in 11.5 patient years. These findings show that in patients receiving continuous ambulatory peritoneal dialysis peritonitis may be prevented by enclosing the connection process and sterilising the introduced air and tubing ends.