A five-year study of the microbiologic results of exit site infections and peritonitis in continuous ambulatory peritoneal dialysis

We studied the culture results from 321 continuous ambulatory peritoneal dialysis (CAPD) related infections (exit site, tunnel infections, and peritonitis) in 137 patients over a 5-year period to determine the contribution of exit site and tunnel infections to peritonitis and catheter loss. Seventeen percent of peritonitis episodes were associated temporally and by microbiologic results with exit site or tunnel infections. Twenty-one percent of exit site and tunnel infections and 20% of peritonitis episodes resulted in catheter loss. Peritonitis due to Staphylococcus aureus was more likely to be associated with an exit site or tunnel infection and was more likely to result in loss of the catheter than peritonitis due to Staphylococcus epidermidis. Peritonitis and exit site infections due to Pseudomonas sp also frequently resulted in catheter removal. We found that exit site infections cause significant morbidity in CAPD patients. Further studies in this area are needed.     

Preventing Staphylococcus aureus infection during chronic peritoneal dialysis.

In the interest of studying the prevention of chronic peritoneal dialysis infections, serial studies of the bacterial epidemiology in peritonitis and of antibiotic prophylaxis, respectively, were carried out. For 18 months, prospective evaluation of catheter exist site cultures, performed at the time patients developed acute peritonitis, showed that Staphylococcus aureus peritonitis was associated with concordant S. aureus at the exist site in 85% of cases, significantly more frequent than that for other organisms (P less than 0.02). Furthermore, active inflammation along with concordant culture results at the exit site characterized more than 60% of S. aureus peritonitis cases, also significantly more than that for other organisms (P less than 0.01). Over the ensuing 2 yr, patients beginning chronic peritoneal dialysis with a new percutaneously placed catheter were prospectively entered into a randomized, controlled trial of long-term antibiotic prophylaxis with trimethoprim-sulfamethoxasole. Patients receiving prophylaxis tended to have fewer episodes of peritonitis; however, the lower rate of peritonitis reached statistical significance only comparing patients who were S. aureus carriers at entry into the study to patients who were not S. aureus carriers. In particular, the prophylaxis trial seemed to reduce the specific incidence of S. aureus peritonitis overall, with S. aureus appearing in only 2 of 28 total peritonitis episodes among treated patients as compared with 11 of 37 total episodes among non-treated patients (P less than 0.01). Further analysis of the time to first peritonitis suggests that the effect of prophylaxis was most prominent during the first 3 months of therapy (P less than 0.02) rather than later in the course of treatment.(ABSTRACT TRUNCATED AT 250 WORDS)     

Catheter-related infections in peritoneal dialysis patients: New aspects

SUMMARY: Catheter-related infections remain a major cause of technical dropout in peritoneal dialysis patients. Staphylococcus aureus (S. aureus) is the most important causative organism of these infections. the objective of this paper is to give an overview of recent developments in the prophylaxis and therapy of infectious catheter complications. It has been shown that prophylactic therapy, with mupirocin or rifampin, results in a decrease of catheter-related infections. However, due to clinical problems associated with long-term antibiotic therapy, prophylactic treatment should be restricted to patients at high risk of developing these infections, such as diabetic exit-site carriers, immunosuppressed patients and non-diabetic, non-immunosuppressed patients with two or more S. aureus positive nasal cultures. the prognosis of catheter-related infections depends on the respective organism and the extent of inflammation. Tunnel sonography is of major importance for early diagnosis of tunnel involvement and for estimating the outcome of tunnel infections. In patients with deep tunnel infection showing marked sonographic improvement two weeks after starting therapy, antibiotic treatment should be prolonged, whereas lack of sonographic improvement is associated with a high risk of catheter loss. In patients with tunnel infection and simultaneous peritonitis, catheter removal is recommended.     

Prevention of infectious complications in peritoneal dialysis: best demonstrated practices

Peritoneal dialysis (PD) related infections continue to be a serious complication for PD patients. Peritonitis can be associated with pain, hospitalization and catheter loss as well as a risk of death. Peritonitis risk is not evenly spread across the PD population or programs. Very low rates of peritonitis in a program are possible if close attention is paid to the causes of peritonitis and protocols implemented to reduce the risk of infection. Protocols to decrease infection risk in PD patients include proper catheter placement, exit-site care that includes Staphylococcus aureus prophylaxis, careful training of patients with periodic retraining, treatment of contamination, and prevention of procedure-related and fungal peritonitis. Extensive data have been published on the use of antibiotic prophylaxis to prevent exit site infections. There are fewer data on training methods of patients to prevent infection risk. Quality improvement programs with continuous monitoring of infections, both of the catheter exit site and peritonitis, are important to decrease the PD related infections in PD programs. Continuous review of every episode of infection to determine the root cause of the event should be routine in PD programs. Further research is needed examining approaches to decrease infection risk.     

Xanthomonas maltophilia infection in chronic peritoneal dialysis patients

Xanthomonas maltophilia infection has only been occasionally reported in patients receiving chronic peritoneal dialysis. We describe four cases of Xanthomonas maltophilia infection associated with chronic peritoneal dialysis. Two patients presented with peritonitis and two with exit site infection. All patients were diabetics, who immediately prior to the study had not received antibiotic therapy. Failure to respond to multiple antibiotic therapy resulted in catheter removal in both patients with peritonitis. In those patients with only exit site infections, dialysis could be continued following antibiotic therapy and catheter replacement in one. Catheter loss in our patients was directly attributed to peritonitis with Xanthomonas maltophilia infection.     

Randomized, double-blind trial of antibiotic exit site cream for prevention of exit site infection in peritoneal dialysis patients

Infection is the Achilles heel of peritoneal dialysis. Exit site mupirocin prevents Staphylococcus aureus peritoneal dialysis (PD) infections but does not reduce Pseudomonas aeruginosa or other Gram-negative infections, which are associated with considerable morbidity and sometimes death. Patients from three centers (53% incident to PD and 47% prevalent) were randomized in a double-blinded manner to daily mupirocin or gentamicin cream to the catheter exit site. Infections were tracked prospectively by organism and expressed as episodes per dialysis-year at risk. A total of 133 patients were randomized, 67 to gentamicin and 66 to mupirocin cream. Catheter infection rates were 0.23/yr with gentamicin cream versus 0.54/yr with mupirocin (P = 0.005). Time to first catheter infection was longer using gentamicin (P = 0.03). There were no P. aeruginosa catheter infections using gentamicin compared with 0.11/yr using mupirocin (P < 0.003). S. aureus exit site infections were infrequent in both groups (0.06 and 0.08/yr; P = 0.44). Peritonitis rates were 0.34/yr versus 0.52/yr (P = 0.03), with a striking decrease in Gram-negative peritonitis (0.02/yr versus 0.15/yr; P = 0.003) using gentamicin compared with mupirocin cream, respectively. Gentamicin use was a significant predictor of lower peritonitis rates (relative risk, 0.52; 95% confidence interval, 0.29 to 0.93; P < 0.03), controlling for center and incident versus prevalent patients. Gentamicin cream applied daily to the peritoneal catheter exit site reduced P. aeruginosa and other Gram-negative catheter infections and reduced peritonitis by 35%, particularly Gram-negative organisms. Gentamicin cream was as effective as mupirocin in preventing S. aureus infections. Daily gentamicin cream at the exit site should be the prophylaxis of choice for PD patients.     

Prevention of Peritonitis in Peritoneal Dialysis

Reducing the frequency of peritonitis for patients undergoing peritoneal dialysis (PD) continues to be a challenge. This review focuses on recent updates in catheter care and other patient factors that influence infection rates. An experienced nursing staff plays an important role in teaching proper PD technique to new patients, but nursing staff must be cognizant of each patient's unique educational needs. Over time, many patients become less adherent to proper dialysis technique, such as washing hands or wearing a mask. This behavior is associated with higher risk of peritonitis and is modifiable with re‐training. Prophylactic antibiotics before PD catheter placement can decrease the infection risk immediately after catheter placement. In addition, some studies suggest that prophylaxis against fungal superinfection after antibiotic exposure is effective in reducing fungal peritonitis, although larger randomized studies are needed before this practice can be recommended for all patients. Over time, exit site and nasal colonization with pathogenic organisms can lead to exit‐site infections and peritonitis. For patients with Staphylococcus aureus colonization, exit‐site prophylaxis with either mupirocin or gentamicin cream reduces clinical infection with this organism. Although there are limited data for support, antibiotic prophylaxis before gastrointestinal, gynecologic, or dental procedures may also help reduce the risk of peritonitis.     

A review of Staphylococcus aureus exit-site and tunnel infections in peritoneal dialysis patients

Staphylococcus aureus peritoneal exit-site and tunnel infections are a source of considerable morbidity for peritoneal dialysis patients. These infections are difficult to resolve, can lead to peritonitis, and often require removal of the peritoneal catheter. Staphylococcal nasal carriage is the major risk factor for S aureus exit-site infections and peritonitis episodes. In the future, the identification of patients who are S aureus nasal carriers and then treatment of the carriage state with rifampin may prove to be a means of decreasing infection rates. The best treatment for S aureus exit-site and tunnel infections has not been established. Treatment regimens in general use include oral antibiotics or intraperitoneal vancomycin. The optimal length of therapy is also unclear. Since the development of the disconnect peritoneal dialysis system, S aureus, rather than the Staphylococcus epidermidis, is the leading cause of peritonitis. To further decrease peritonitis rates, attention must now be directed at catheter-related peritonitis episodes, with S aureus the most common cause of such episodes. Controlled, prospective studies designed to investigate methods of preventing and treating S aureus exit-site infections in peritoneal dialysis patients are needed.     

Ultrasound as a tool in the diagnosis and management of exit-site infections in patients undergoing continuous ambulatory peritoneal dialysis

Ultrasonographic examination of the subcutaneous course and exit site of the Tenckhoff catheter in patients undergoing continuous ambulatory peritoneal dialysis (CAPD) was performed to evaluate catheter-related infections. Real-time ultrasound studies were performed in 24 patients with initial exit-site infections; clinically suspected tunnel infections were excluded from analysis. A peri-catheter sonolucent fluid collection, considered a positive study, was demonstrated in 13 ultrasound examinations and tended to be organism-specific; eight of 12 Staphylococcus aureus exit-site infections and three of four gram-negative exit-site infections had positive studies. Only two of seven Staphylococcus epidermidis exit-site infections were initially positive on ultrasound examination. Nine of 13 patients with positive ultrasound studies ultimately lost their catheters to infection despite weeks of parenteral antibiotic therapy and local incision and drainage. There were 11 negative ultrasound studies. Only one of these patients' catheters was lost because of infection. In some episodes of CAPD-associated exit-site infections, especially those caused by S aureus and gram-negative organisms, ultrasound examination of the catheter course may be useful to diagnose unsuspected tunnel infections, direct early therapy, and confirm resolution or persistence of the infections.     

Nontuberculous mycobacterial exit-site infection and abscess in a peritoneal dialysis patient

Nontuberculous mycobacterial infections of peritoneal dialysis catheter exit sites have rarely been reported in patients on peritoneal dialysis. We report here a case of Mycobacterium abscessus exit site infection with abdominal wall abscess formation in an adolescent on peritoneal dialysis, which required long-term antibiotic therapy, peritoneal dialysis catheter removal, and surgical debridement of the abscess. Nontuberculous mycobacteria should be considered as a possible causative organism for an exit site infection that fails to respond to usual antibiotic therapy. Nontuberculous mycobacterial exit site infections may require peritoneal dialysis catheter removal and surgical debridement.     

Management of bacterial peritonitis and exit‐site infections in continuous ambulatory peritoneal dialysis*

SUMMARY: Peritonitis and exit‐site infections remain the most important limitations to the delivery of continuous ambulatory peritoneal dialysis (CAPD). Contamination of the peritoneum, from endogenous or exogenous sources, is responsible for most peritonitis episodes. Patients usually present with a cloudy bag, although other causes should be distinguished. Clinical suspicion of peritonitis should be followed rapidly by microbiological examination and empirical treatment. Microbiological confirmation allows for subsequent treatment based on sensitivities. Other interventions such as catheter removal may be appropriate in some patients. Exit‐site infections should also be identified and treated early. Peritonitis may be further prevented by adequate exit‐site care, hygienic methods, and techniques to minimise early contamination of the exit site. Mupirocin may also have a role in preventing infections caused by Staphylococcus aureus.     

Use of pulsed-field gel electrophoresis in the analysis of recurrent Staphylococcus aureus infections in patients on continuous ambulatory peritoneal dialysis

BACKGROUND/AIM: The purpose of this study was to evaluate pulsed-field gel electrophoresis (PFGE) for distinguishing between relapse and reinfection of Staphylococcus aureus infections in patients on continuous ambulatory peritoneal dialysis (CAPD). METHODS: Between July 1993 and May 1997, 4 patients with recurrent CAPD-associated infections caused by S. aureus we enrolled in this study. There were nine episodes of peritonitis, one episode of temporary double lumen catheter infection, and one episode of Hickman catheter infection. A total of eleven S. aureus isolates were collected from peritoneal fluid (n = 9) and blood (n = 2). PFGE typing was applied. RESULTS: In our study, from PFGE typing, the 11 S. aureus isolates were classified into seven patterns. Antibiogram profiling classified only four patterns. Patient A had a reinfection by another strain of S. aureus, and patient B had three episodes of peritonitis caused by the same strain of S. aureus due to exit site infections. Patient C had two episodes of CAPD peritonitis caused by two different strains, respectively. Patient D had four episodes of S. aureus infection (three CAPD peritonitis and one bacteremia); the first two episodes of peritonitis were caused by an identical strain of S. aureus, whereas the subsequent two infections were caused by other organisms. CONCLUSION: PFGE has a high discriminatory power and can be an assistant method to antibiogram profiling for distinguishing relapse from reinfection in CAPD-associated peritonitis.     

Do topical antibiotics reduce exit site infection rates and peritonitis episodes in peritoneal dialysis patients? The Pan Thames Renal Audit

Background and objectives: Peritonitis is the major cause of peritoneal dialysis (PD) technique failure. Prophylactic topical antibiotics have been reported to reduce peritoneal dialysis catheter exit site infections (ESI) and peritonitis rates. Methods: We audited the effect of different exit site practices in the 12 Pan Thames and South East England PD centres, on ESIs and peritonitis between 2005 and 2008. Results: PD patients used prophylactic mupirocin (n=1,270), gentamicin (n=502) and no prophylactic antibiotics (n=1,203); annualised ESI rates were reduced with mupirocin (median 0.18, interquartile range [IQR] 0.13-0.23, patient episodes per year, vs. median 0.32, IQR 0.24-0.69, for no antibiotic prophylaxis, p<0.01). Gentamicin treatment was not significantly lower (median 0.29, IQR 0.21-0.47). Staphylococcal ESIs accounted for 39.6% in the no antibiotic group and fell to 25.7% with mupirocin and 28.2% with gentamicin. Despite the reduction in ESIs, there was no significant reduction in peritonitis rates (no antibiotics: median 0.56, IQR 0.5-0.65; mupirocin: median 0.55, IQR 0.53-0.75; and gentamicin: median 0.47, IQR 0.32-0.65). In particular, mupirocin did not reduce Staphylococcus aureus peritonitis rates. Conclusions: Topical antibiotics have been reported to reduce both ESI and peritonitis rates in controlled trials, and although in this audit of routine clinical practice, topical mupirocin did reduce overall ESI rates and both mupirocin and gentamicin reduced S. aureus ESIs, neither reduced overall peritonitis rates.     

Decrease in infections with the introduction of mupirocin cream at the peritoneal dialysis catheter exit site

Staphylococcus aureus associated peritonitis and catheter exit site infections (ESI) are an important cause of hospitalization and catheter loss in the patients undergoing chronic peritoneal dialysis (PD). We aimed to determine the potential effectiveness of the application of mupirocin cream at the catheter exit site in preventing exit site infection and peritonitis. METHODS: This prospective historically controlled study was done in a total of 86 patients who entered our PD program from April 1999 to January 2001. They were instructed to apply Mupirocin cream 2% to the exit site daily or on alternate days. The patients were not screened to determine whether they were staphylococcus aureus carriers. One hundred and thirteen patients on PD prior to April 1999 acted as historical controls. Both groups were followed prospectively for a period of 22 months. RESULTS: In the study group application of mupirocin lead to a significant reduction in the incidence rate of both exit site infections overall (0.43 vs. 0.09; p<0.0001) and ESI due staphylococcus aureus (0.14 vs. 0.02; p=0.004) amounting to a relative reduction of 79% and 85% respectively. Although the overall incidence of peritonitis did not change (0.28 vs. 0.26; p=0.7) there was a significant reduction in peritonitis caused by staphylococcus aureus (0.07 vs. 0; p=0.01) Although only one catheter required removal in the mupirocin group as against 5 in the control group, this was not statistically significant. CONCLUSIONS: Mupirocin application at the exit site significantly lowers the incidence of ESI and peritonitis caused by staphylococcus aureus without any significant side effects.     

Clinical course of peritonitis due to Pseudomonas species complicating peritoneal dialysis: a review of 104 cases

BACKGROUND: Peritonitis due to Pseudomonas species is a serious complication in continuous ambulatory peritoneal dialysis (CAPD) patients. The clinical course of peritonitis due to Pseudomonas complicating CAPD remains unclear. METHODS: All of the Pseudomonas species episodes of peritonitis in our dialysis unit were studied from 1995 to 1999. During this period, there were 859 episodes of peritonitis recorded, 113 of which were caused by the Pseudomonas species. Nine episodes were excluded because they were mixed growth. The remaining 104 episodes in 68 patients were reviewed. RESULTS: The underlying renal diagnosis and prevalence of comorbid conditions of the 68 patients were similar to those found in our entire dialysis population. There was a history of antibiotic therapy within 30 days of the onset of peritonitis due to the Pseudomonas species in 69 episodes (66.3%). In 47 episodes (45.2%) there was a concomitant exit site infection. The overall primary response rate was 60.6% and the complete cure rate was 22.1%. The presence of exit site infection was associated with a lower primary response rate (22 in 47 vs. 41 in 57 episodes, P < 0.01) and a lower complete cure rate (5 in 47 vs. 18 in 57 episodes, P < 0.02). The episodes that had received recent antibiotic therapy had a significantly lower complete cure rate than the de novo cases (8 in 69 vs. 15 in 35 episodes, P < 0.001). Episodes receiving third-generation cephalosporin as part of the initial antibiotic regimen had a significantly higher primary response rate than the ones that initially received aminoglycoside (54 in 81 episodes vs. 8 in 22 episodes, P < 0.05), but their complete cure rates were similar. Twenty-four cases failed to respond to antibiotics and the Tenckhoff catheter was removed. The chance of returning to CAPD was higher when the Tenckhoff catheter was removed on day 10 than on day 15 (9 in 14 cases vs. 5 in 10 cases), although the result was not statistically significant. The Tenckhoff catheter was removed and replaced at another site simultaneously in another 14 cases after the effluent cleared up. None of these patients had a relapse of peritonitis within three months. CONCLUSIONS: Recent antibiotic therapy is the major risk factor for peritonitis due to the Pseudomonas species. Exit site infection and recent antibiotic therapy are associated with poor therapeutic response to antibiotics. When the therapeutic response is suboptimal, early Tenckhoff catheter removal may help preserve the peritoneum for further peritoneal dialysis. Elective Tenckhoff catheter exchange after clearing up the peritoneal dialysis effluent may also reduce the likelihood of relapse. It is desirable to use third-generation cephalosporin in the initial antibiotic regimen for peritonitis treatment in localities with a high incidence of peritonitis due to the Pseudomonas species.     

Pseudomonas exit site infections in continuous ambulatory peritoneal dialysis patients.

The purpose of this study is to examine the natural history of Pseudomonas aeruginosa exit site infections in continuous ambulatory peritoneal dialysis (CAPD) patients treated with oral ciprofloxacin and local exit site care. A retrospective view was undertaken of 18 episodes of P. aeruginosa exit site infections developing in 17 patients maintained on CAPD during 1989 and 1990. Standardized therapy for the exit site infection consisted of oral ciprofloxacin (500 mg twice daily) and local exit site care with antiseptic agents. Fifteen (83%) of 18 of the pseudomonas exit site infections resolved with therapy. Three episodes (17%) required catheter removal to successfully eradicate the infection. Four of the 15 patients whose exit site infections resolved developed P. aeruginosa peritonitis 2 to 9 months after the clinical resolution of the exit site infection. The majority of pseudomonas exit site infections in CAPD patients can be successfully treated with oral ciprofloxacin and local care. Approximately 17% of the patients in this study required catheter removal to successfully eradicate the infection and an additional 22% of the patients developed pseudomonas peritonitis several months after the resolution of the exit site infection.     

New insights on preventing and managing peritonitis

Methods to prevent peritonitis are an essential component of any successful peritoneal dialysis (PD) program. Careful attention to training of the parents and child on the proper technique of PD and avoidance of manual spiking by using an assist device for the cycler, or use of the double-bag system for continuous ambulatory PD, should decrease risk of peritonitis from touch contamination. Secondly, reduction of peritonitis can be achieved through reduction of exit site infections by use of mupirocin antibiotic cream at the exit site of the PD catheter as part of routine care. If an exit site infection develops and is refractory to therapy, then the PD catheter can be successfully replaced as a single procedure, to reduce the risk of peritonitis. The third step in reducing the risk of peritonitis is to avoid repetitive episodes with the same organism. This may again involve replacing the catheter; as long as the effluent can be cleared, this again can be performed as a single procedure, thus allowing the child to avoid the trauma of hemodialysis. The focus in pediatric PD programs must always be on preserving the peritoneal membrane, and not on preservation of the catheter. With careful attention, peritonitis can become an uncommon event.     

Effect of a silver device in preventing catheter-related infections in peritoneal dialysis patients: silver ring prophylaxis at the catheter exit study

Catheter-related infections remain a significant cause of method failure in chronic peritoneal dialysis (PD) therapy. Given the increasing antibiotic resistance, such nonpharmacological strategies as local silver devices attract more interest. To establish whether a silver ring device (designed by Grosse-Siestrup in 1992) mounted onto the PD catheter and placed at the exit site at skin level is effective in preventing exit-site and other catheter-related infections, a prospective 12-month, multicenter, controlled study stratified by diabetes status was conducted. The study subjects were assessed by an extensive structured inventory, including a broad spectrum of control variables, such as age, body mass index (BMI), Staphylococcus aureus carrier status, catheter features, mode and quality of PD therapy, comorbidity, and psychosocial rehabilitation. Ten experienced German outpatient dialysis centers (seven adult, three pediatric) participated in the trial. All eligible patients (n=195) from the study area without catheter-related infections during the ascertainment period were included (incidental subjects undergoing PD therapy for at least 3 months). The main outcome measures were the occurrence of first exit-site infections (primary study end point), sinus tract/tunnel infection, and peritonitis. Ninety-seven patients were assigned to the silver ring and 98 patients to the control group. Baseline characteristics of age, sex, proportion of pediatric and incidental patients, S aureus carrier status, and other variables were similar in both groups. The incidence of infections in the silver ring group versus the control group was as follows: 23 of 97 versus 16 of 98 patients had exit-site infections, 12 of 97 versus 12 of 98 patients had sinus tract/tunnel infections, 16 of 97 versus 18 of 98 patients had peritonitis, respectively. Kaplan-Meier analysis for the probability of an infection-free interval showed no statistical difference (log-rank test) between the two groups. Displacement of the silver ring contributed to study termination in 6% of the study group patients, including two patients with catheter loss. Univariate analysis and multiple logistic regression identified younger age (<50 years), low serum albumin level (<35 g/L), number of previously placed PD catheters, short cuff-exit distance (<2 cm), and S aureus nasal carriage as risk factors for the development of exit-site infections. In conclusion, our study does not show any benefit of the silver ring in preventing catheter-related infections in PD patients. Thus, prevention of infection-related method failure in PD still has to rely on conventional antibiotic treatment strategies and less so on alternative methods.     

Frequent involvement of the internal cuff segment in CAPD peritonitis and exit-site infection--an ultrasound study

BACKGROUND.: The extent of involvement of the subcutaneous Tenckhoff cathetertract in CAPD peritonitis and catheter-related infections isof major therapeutic importance. By definition, both peritonitisand exit-site infections do not involve the catheter tract.However, diagnosis of these infections as well as the more sinistertunnel infection is based mainly on clinical signs. METHODS.: We examined the usefulness of ultrasound examination (US) ofthe catheter tract in delineating catheter-related (exit-siteand tunnel) infections, and their relationship to each otherand to peritonitis. CAPD patients with no evidence of peritonitisor catheter-related infections for 6 months prior to examinationserved as controls. US were performed by one of two experiencedradiologists using the Acuson 128XP/10 scanner with a 7-MHzlinear transducer. A positive US was defined as an area of hypoechogenicity(indicative of fluid collection) >2 mm in width along anyportion of the catheter tract. Findings were localized intosegments (S) as follows: S1, limited to external cuff; S2, intercuffsegment adjacent to the external cuff; S3, intercuff segmentadjacent to the internal cuff; S4, limited to the internal cuff;and S5, involvement extending throughout the catheter tract. RESULTS.: Between March 1993 and January 1995, 39 CAPD patients, all witha double-cuff straight Tenckhoff catheter with the exit sitesituated above the point of entry into the peritoneum were studied.A total of 56 US were performed divided among 26 episodes ofperitonitis, four tunnel infections, 13 exit-site infections,and 13 controls. There were 30 positive US distributed among16 peritonitis, four tunnel, eight exit site infections andtwo control patients. The two positive controls went on to develop peritonitis within1 month of the US. The majority of the US findings (13/16 inepisodes of peritonitis and 5/8 exit site infections) were localizedto segment 4, that is, to the internal cuff region. Apart from a significant increase in width in all infected segmentsversus a normal tunnel, no differences in size were seen betweenperitonitis, exit-site, or tunnel infections, nor were thereany differences in size and localization in these infectionswhen comparing the offending organism (Gram-positive, negative,or culture negative). CONCLUSIONS.: We conclude that peritonitis and exit-site infections are frequentlyaccompanied by involvement of the catheter tract. The localizationof infection to the internal cuff region in cases of exit-siteinfection probably occurred as a result of downward migrationalong the catheter tract. This supports the notion that ideallythe exit site should be pointing caudally or that the peritonealcatheter have a swan-neck configuration. With regard to peritonitis,infection within the peritoneal cavity appears to extend andinvolve the internal cuff region. Thus both the internal andexternal cuffs do not seem to pose an effective barrier againstthe spread of infection. Based on our data, we recommend thatUS be performed as a routine investigation in all cases of exit-siteinfection and in cases of refractory or relapsing peritonitis.     

Prevention of peritoneal dialysis-related infections

Despite substantial advances in peritoneal dialysis (PD) as a renal replacement modality, PD-related infection remains an important cause of morbidity, technique failure, and mortality. This review describes the microbiology and outcomes of PD peritonitis and catheter infection, followed by a discussion of several strategies that may reduce the risk of PD-related infections. Strategies that are reviewed include use of antibiotics at the time of PD catheter insertion, selection of PD catheter design and insertion technique, patient training, PD connectology, exit site prophylaxis, periprocedural prophylaxis, fungal prophylaxis, and choice of PD solutions.