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.     

Cuff-shaving procedure. A rescue treatment for exit-site infection unresponsive to medical therapy

We performed 41 cuff-shaving procedures in 38 patients on continuousambulatory peritoneal dialysis (CAPD) with exit-site infectionunresponsive to medical treatment. Cuff shaving was performedon three patients with two catheters each. This procedure waseffective in eliminating 50% of S. aureus exit-site infectionand all S. epidermidis exit-site infection, but was ineffectivein Gram-negative exit-site infection. After cuff-shaving procedure,20 catheters (49%) were removed; 11 for persistent tunnel infectionand nine because of development of secondary peritonitis. Theprobability of catheter survival at 1 year was 50% and remainedstable thereafter. Cuff-shaving procedure may be a valuablemode of therapy for treating patients with S. aureus and/orS. epidermidis exit-site infection unresponsive to medical treatment.     

Surgical salvage of peritoneal dialysis catheters from chronic exit-site and tunnel infections

BACKGROUND: Chronic exit-site and tunnel infections of the peritoneal dialysis catheter are significant causes of catheter loss. Surgical salvage procedures that can effectively resolve the infection and preserve dialysis are of major importance. METHODS: Thirteen patients with chronic exit-site and tunnel infections underwent surgical salvage consisting of unroofing the tunnel tract and shaving of the superficial catheter cuff. A control group of 138 patients implanted during the same time span as the study group was used for infection rate and survival comparisons. RESULTS: The salvage procedure cured the infection in all patients. No dialysate leaks occurred. Peritoneal dialysis was not interrupted. Surgical salvage provided successful long-term peritoneal dialysis that was equivalent to the cohort dialysis population. CONCLUSION: Surgical salvage by unroofing/cuff shaving is an effective long-term solution for chronic exit-site and tunnel infection.     

Randomized controlled trial of prophylactic rifampin for peritoneal dialysis-related infections

Staphylococcal infections are a major cause of catheter infections and peritonitis in peritoneal dialysis patients. Since catheter-related infections are associated with nasal carriage of Staphylococcus aureus in this population, we studied the effect of intermittent rifampin, an antibiotic known to decrease S aureus nasal carriage, on catheter-related infections and peritonitis. We randomly assigned 64 patients to receive either rifampin 300 mg twice daily for 5 days every 3 months or no treatment. The rifampin-treated patients had a significant delay in time to first catheter-related infection (P less than 0.015) and significantly fewer catheter-related infections overall (P less than 0.001). The catheter-related infection rate in rifampin-treated patients was .26 per patient-year versus .93 per patient-year in untreated patients. Multivariate analysis defined baseline colonization of nares or catheter exit-site and prior renal transplant as risk factors for catheter-related infections. There was no significant difference in peritonitis rates between groups, although the trend was for a delayed time to first episodes and fewer episodes in rifampin-treated patients. Adverse effects necessitated withdrawal of rifampin in four patients. We conclude that intermittent rifampin administration is effective in decreasing catheter-related infections in a peritoneal dialysis population.     

Effect of rifampin onStaphylococcus aureus colonization in children on chronic peritoneal dialysis

The efficacy of rifampin in eliminatingStaphylococcus aureus colonization was evaluated in a pediatric peritoneal dialysis population. Six children with documented nasal colonization were treated for 7 days with rifampin and cloxacillin. Although antimicrobial therapy eliminated nasal carriage in all patients, recolonization occurred in 66%. Exit site colonization proved difficult to eradicate with negative cultures documented in only 3 of 5 children after rifampin/cloxacillin therapy. AlthoughS. aureus carriage is a risk factor forS. aureus infections, efforts to eradicate carriage with rifampin are hindered by rapid recolonization.     

Access-related complications in peritoneal dialysis in developing countries

Access-related complications differ considerably between acute and chronic peritoneal dialysis as a result of differences in catheter design, catheter material, number of cuffs, break in period, and the duration of peritoneal dialysis. Pain, which is the commonest complication of acute peritoneal dialysis, is seen in 56% to 75% followed by blood tinged dialysate effluent in 30%, pericatheter leak in 14% to 36%, catheter malfunction in 12% to 28%, bowel injury in 0.1% to 1.3%, rarely bladder injury and peritonitis in 2.5%. In chronic peritoneal dialysis, the incidence of exit-site infections are seen anywhere between 1 episode in 27.3 patients months to 1 episode in 41.9 patients months, and pericatheter leak is seen in 5.2%. Technique of exit-site care is variable in different countries, and regular use of mupirocin ointment at the exit site is practiced in different centers.     

Adult staphylococcus scalded skin syndrome in a peritoneal dialysis patient

Staphylococcal scalded skin syndrome (SSSS), a generalized exfoliative dermatitis complicating infections by exfoliative toxin-producing strains of Staphylococcus aureus, is rarely observed in adults, especially in those with chronic renal failure. In contrast to the mortality in infants, the mortality in adults is usually high. A case of generalized SSSS in a peritoneal dialysis patient is reported. A-62-year old Japanese man in whom peritoneal dialysis had been carried out was admitted to our hospital with acute peritonitis. It was intractable peritonitis in terms of resistance to various antibiotics; however, improvement of the peritonitis was shown after the injection of vancomycin. Nine days after the completion of this medication, erythema appeared in the eyes and mouth, and around the nostrils, with an exothermic reaction at 39.0°C. Radial cracks formed in the face within a few days, and the erythema rapidly expanded to the neck, axilla, the whole body. The blood pressure was also lowered, and this led to a state of shock. Culture of skin biopsy specimens yielded identical strains of S. aureus. A presumptive diagnosis of SSSS was made. The patient was treated with antibiotics that were effective against the organisms and with both fluid supplementation and dopamine, resulting in subsidence of the signs and symptoms. The exothermic reaction and skin symptoms were improved promptly, with improvement in the general condition, including the state of shock. This appears to be the first reported case of SSSS caused by S. aureus in an adult patient with peritoneal dialysis who was treated successfully. It is very important that SSSS be differentiated from toxic epidermal necrosis, as the treatment is different. Received: March 5, 2002 / Accepted: October 10, 2002 Correspondence to:S. Iwasaki     

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.     

Peritonitis in peritoneal dialysis patients after renal transplantation

Background. The occurrence of peritonitis in peritoneal dialysis patients after renal transplantation during immunosuppression might increase morbidity and mortality. Hence the timing of catheter removal is still controversial. The associated risk factors of this complication have not been analyzed. Methods. We analyzed, retrospectively, the incidence of peritonitis within 90 days after transplantation, its associated morbidity and mortality, as well as risk factors. From 1980 until March 1995, 238 consecutive kidney transplants in peritoneal dialysis patients were performed. Univariate and multivariate logistic regression analysis were used to identify risk factors for the development of peritonitis. Results. 232 cases (141 men, 91 women) were available for analysis. In 191 patients, the catheter was removed with a mean interval after transplantation of 122 days (range 0-573). Thirty peritonitis episodes with predominantly Staphylococcus aureus (10/30) or Gram-negative bacteria (12/30) were observed. Independent risk factors before transplantation were the total number of peritonitis episodes (P<10^-5), previous peritonitis with S. aureus bacteria (P<10^-5), and male sex (P<0.004). Risk factors after transplantation were technical surgical problems (P<10^-5), more than two rejection episodes (P<0.02), permanent graft non-function (P<0.026), and urinary leakage (P<0.035). Conclusions. Transplantation without simultaneous peritoneal catheter removal is feasible. However, this increases the risk of peritonitis after transplantation. Early catheter removal should be considered seriously in those patients at risk. When peritonitis develops, antibiotic treatment should be directed against Gram-positive as well as Gram-negative bacteria until culture results are available. Keywords: catheter; peritoneal dialysis; peritonitis; risk factors; transplantation      

Peritonitis in children with automated peritoneal dialysis: a single-center study of a 10-year experience

Peritoneal dialysis (PD) constitutes the preferred dialysis modality for children requiring renal replacement therapy with peritonitis being one of the most common complications of PD. This study was performed to evaluate the epidemiology, microbiology, and outcomes of PD-associated peritonitis in Greek children for a 10-year period. A total of 27 patients (16 males) with a mean age 121.8?±?57.2 months were retrospective analyzed. Patients were on PD therapy for a mean duration of 45.2?±?26.1 months. We found 23 episodes of PD-associated peritonitis occurred in 9 out of 27 patients (0.23 episodes/patient-year), with four patients experienced two or more peritonitis episodes. Gram-positive bacteria were responsible for 15 (65.2%) peritonitis episodes, with Staphylococcus aureus being the predominant specie isolated in 30.4% of cases. A total of seven episodes of exit-site infections (ESIs) were identified in five patients (0.069 episodes/patient-year) with the most common bacteria isolated being S. aureus (57.4%). Initial antibiotic treatment included intraperitoneal vancomycin plus ceftazidime in the majority of cases (82.6%). At the end of study, 12 (44.4%) patients remained on PD, 11 (41.8%) underwent renal transplantation, 2 (7.4%) shifted to hemodialysis and unfortunately, two patients (7.4%) died. Conclusively, our study revealed a noticeable low peritonitis and ESIs rate as compared to international data and represents the first evaluation of the characteristics and outcomes of peritonitis in the Greek pediatric PD population.     

Peritoneal Catheters and Related Infections

Catheter related infectious complications (exit-site infections, tunnel infections, and peritonitis) remain the major reasons for technique failure during the three decades since, continuous ambulatory peritoneal dialysis (CAPD) treatment has been first established. Despite improvements in catheter’s survival rates, catheter related complications result in an increase in the cumulative patients’ morbidity and often leading to the catheter removal. The ideal catheter provides reliable and rapid dialysate flow rates without leaks or infections. Among several types, the double-cuff straight Tenckhoff catheter, developed in 1968, is still the most widely used, although its use is decreasing in favour of swanneck catheters. Although there are onlu few well-designed trials comparing catheters and catheters related infectious complications, controlling for all other important variables, no difference in these complications among the main types of catheters was seen. The single cuff catheters have been associated with a shorter survival rate and time to the first peritonitis episode than the double-cuff catheters. Also exit-site infections were found to be more frequent and significantly more resistant to treatment with single-cuff compared to double-cuff ones. Finally, better results have been reported with the latest developed presternal peritoneal dialysis catheter both regarding survival rates and exit-site infection and peritonitis rates. Recently a renewed interest in continuous flow peritoneal dialysis stimulated inventions of imaginative, double-lumen catheters since a suitable peritoneal access is a sine qua non condition for the development of this new technique of peritoneal dialysis.     

Toxic shock syndrome with Staphylococcus aureus exit-site infection in a patient on peritoneal dialysis

Toxic shock syndrome (TSS) associated with exit-site infection but without peritonitis has not been described. We report a case of TSS with an isolated Staphylococcus aureus exit-site infection in a boy on chronic peritoneal dialysis. The exit site had minimal erythema and no purulence. This report re-emphasizes the fact that mildly appearing cutaneous infections in patients with chronic renal failure may have significant consequences. Particular attention should be given to patients who present with constitutional symptoms that may be of short duration. The importance of culturing all sites in such cases is highlighted. The prevalence of TSS with exit-site infections is unknown, but TSS should be considered in patients presenting with similar features.     

Peritoneal dialysis access: prospective randomized comparison of single-cuff and double-cuff straight Tenckhoff catheters

Background: A prerequisite to the technical success of chronic peritoneal dialysis is a functioning peritoneal catheter. The option of using Tenckhoff catheters with single or double Dacron cuffs has been available for almost 3 decades, but still there is no consensus as to which is the preferable type. Methods: Sixty consecutive patients requiring a catheter for CAPD were randomized to receive either a straight deep single-cuff Tenckhoff catheter or a double-cuff Tenckhoff catheter. The catheters were surgically inserted. Results: There were no early failures. Two subcutaneous cuff extrusions were treated with shaving of the cuff. In the long term, eight patients in both groups required transfer to haemodialysis (5 and 3 prolonged peritonitis, 1 and 0 exit-site infection, 2 and 5 unable to cope or inadequacy of dialysis). There was no significant difference in the probability of developing first episode or peritonitis or exit site infection between the groups. Overall probability of catheter survival was 95.5 and 96.7% at 1 year, 82.7 and 79.9% at 2 in the two groups respectively. Conclusions: There was no significant difference between catheters with single or doble cuffs with respect to catheter survival, episodes of peritonitis and exit-site infections.     

Exit-site and tunnel infections in continuous ambulatory peritoneal dialysis patients

One hundred two exit-site infections (ESI) were diagnosed in 63 of 163 (38.6%) patients, with an incidence of one episode every 23.7 patient-months in patients with a history of ESI, whereas in the overall continuous ambulatory peritoneal dialysis (CAPD) population the incidence was one episode every 48.7 patient-months. In diminishing order of frequency, the bacteria isolated were Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, and Escherichia coli. The probability of remaining free of ESI was 72% at 1 year and 45% at 5 years. The ESI that led to catheter removal were due to S aureus and gram-negative rods. In 13 (48%) of 27 S aureus ESI unresponsive to antibiotics and local care, deroofing and outer cuff shaving completely resolved the ESI. Despite this treatment, the catheters of the remaining 14 patients had to be removed because of peritonitis associated with the tunnel infection. In conclusion, ESI is a major cause of CAPD failure. In our series, shaving the cuff as a rescue treatment was effective for almost 50% of the patients with antibiotic-resistant S aureus ESI.     

Infectious and catheter-related complications in pediatric patients treated with peritoneal dialysis at a single institution

Continuous ambulatory peritoneal dialysis (CAPD) and continuous cycling peritoneal dialysis (CCPD) are the predominant dialytic modalities for the majority of children while awaiting transplantation. Wide acceptability of peritoneal dialysis is hindered by infectious complications. A retrospective review of 367 pediatric patients treated with CAPD/CCPD for at least 3 months from September 1980 through December 1994 revealed that the peritonitis incidence ranged from 1.7 to 0.78 episodes per patient-year. No differences in peritonitis rates were observed between patients treated with CAPD or CCPD. Gram-positive organisms were responsible for the majority of peritonitis episodes. Age, sex, race, primary renal disease, presence of nephrotic syndrome, and serum albumin level were not associated risk factors. Longer time on treatment and diminished serum IgG level were associated with increased peritonitis incidence. Treatment was successfully completed at home in most cases. Almost half of the catheter losses were caused byStaphylococcus, Pseudomonas, and fungal peritonitis and tunnel/exit-site infections. Infectious complications are still the major causes of morbidity and treatment failure in patients treated with CAPD/CCPD. Thus, controlled studies are needed to assess methods for prevention or improvement of peritonitis rates in this patient population.     

Moncrief-Popovich catheter and implantation technique: the AV fistula of peritoneal dialysis

Despite the decrease in peritonitis rate from touch contamination caused by the use of disconnect systems, technique failure in peritoneal dialysis (PD) from pericatheter and exit-site infections in PD remains unchanged. This indicates a failure of current PD catheters to prevent bacterial transfer from exit site to the peritoneal cavity. In 1991, Moncrief and Popovich introduced a new catheter design and implantation technique to address this problem. The catheter is made of silastic, has a coiled tip with 2 cuffs, and an arcuate bend between the cuffs. This would prevent catheter malfunction and leakage of PD fluid. The implantation technique involves embedding of the external segment of the catheter in the subcutaneous tunnel at insertion. The catheter segment is kept embedded for 4 to 6 weeks before externalization. This procedure will allow time for tissue ingrowth on into the external cuff and catheter surfaces between the 2 cuffs, preventing bacterial colonization of the catheter surfaces from the exit wound and thereby reducing pericatheter infections. Thus, the new technique will establish a more effective bacteriologic barrier between the exit wound and the peritoneal cavity than the conventional catheters. Ten years after validation of the catheter design and implantation technique by Moncrief and Popovich, various clinical studies confirm that this new technique of catheter implantation increases catheter life expectancy and reduces pericatheter infections in PD. Like the arteriovenous fistula of haemodialysis, this new catheter remains embedded in subcutaneous tunnel, is exteriorized electively when patient needs to be started on dialysis, and reduces pericatheter and exit-site infections in PD. The new technique, therefore, is widely accepted as a simple, safe, and cost-effective procedure for quality care of PD patients around the world.     

Catheter revision for the treatment of intractable exit site infection/tunnel infection in peritoneal dialysis patients: A single centre experience

Aim: Catheter‐related infection is a major cause of catheter loss in peritoneal dialysis (PD). We evaluated the effect of catheter revision on the treatment of intractable exit site infection (ESI)/tunnel infection (TI) in PD patients who required catheter removal. Methods: We reviewed the medical records of 764 continuous ambulatory peritoneal dialysis (CAPD) patients from May 1995 to April 2011 at our hospital. One hundred and twenty six patients had more than one occurrence of ESI. Catheter revision was performed to treat intractable ESI/TI. Incidence of ESI, causative organisms and the outcomes of catheter revision were analyzed. Results: The total PD duration of all patients was 32 581 months. Three hundred and twelve ESI episodes occurred in 126 patients and the incidence of ESI was 1/104 patient‐months (0.12/patient‐year). The most common causative organism was methicillin‐sensitive Staphylococcus aureus (MSSA) (98 episodes), followed by Pseudomonas aeruginosa (63 episodes) and methicillin‐resistant S. aureus (MRSA) (28 episodes). Among these, catheter revision was required due to intractable ESI/TI in 36 patients. The most common causative organism was MSSA (14 episodes) followed by P. aeruginosa (10 episodes) and MRSA (six episodes) in catheter revision cases. The outcomes of catheter revision were as follows: ESI relapsed in 11 patients (30.6%) after catheter revision. Among them, five patients were treated with antibiotic treatment, two patients required secondary catheter revision, four patients required catheter removal due to ESI/TI accompanying peritonitis. The catheter survival rate after catheter revision was 89.7% in one year. There were no statistical differences in the rates of ESI relapse after catheter revision between ESI caused by P. aeruginosa (5/10, 50%) and ESI caused by S. aureus (6/21, 28.6%). Conclusion: Catheter revision may be an alternative treatment option to treat intractable ESI/TI before catheter removal is considered in PD patients.     

Adherence of Staphylococcus aureus to cultures of human peritoneal mesothelial cells

Strains of Staphylococcus aureus, isolated from the effluentof patients with peritonitis on CAPD (continuous ambulatoryperitoneal dialysis), adhered well to both cultured human mesothelialcells and to fibronectin, but not to laminin or gelatin. Mesothelialcells grown in medium M199 exhibited more surface fibronectincompared to cells grown in MEM-Dval and demonstrated higherlevels of S. aureus adherence. Soluble fibronectin concentrations up to lOµg/ml increasedthe adherence of S. aureusto cultured mesothelial cells. Thedose-response curve was consistent with the binding of fibronectinto a saturable receptor of apparent dissociation constant (K_D)= 1.7xlO^–10 M. This corresponds closely to the K_D (2xlO^–10M) of the staphylococcal fibronectin-binding protein. S. aureus adherence was increased following the preincubationof mesothelial cell monolayers with interleukin-1 and was maximalafter 6 h preincubation. Treating mesothelial cells with interferon-gammafor 48–72 h reduced the adherence of S. aureus.     

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.