Simultaneous catheter replacement and removal in refractory peritoneal dialysis infections

The use of mini-invasive surgical techniques to treat refractory exit-site and tunnel infections in peritoneal dialysis patients: a clinical approach

Peritoneal dialysis-(PD) related infections continue to be a major cause of morbidity and mortality in patients on PD. Although great advances have been made in the prevention and treatment of infectious complications over the past two decades, catheter-related infections represent a significant cause of technical failure in PD. Recent studies support the role of exit-site/tunnel infections in causing peritonitis. Peritonitis secondary to tunnel infection led to catheter loss in most cases. Thus, removing the catheter when exit-site/tunnel infection is refractory to medical therapy has been recommended. This approach requires interrupting PD and, after the placement of a central venous catheter, and transferring the patient to haemodialysis. In order to continue PD, simultaneous catheter removal and replacement of the PD catheter has been suggested. Although simultaneous catheter removal and replacement avoids temporary haemodialysis, it implies the removal/reinsertion of the catheter and the immediate initiation of PD with the risk of mechanical complications, such as leakage and malfunction. Hence, several mini-invasive surgical techniques, such as curettage, cuff-shaving, removal of the superficial cuff, and partial reimplantation of the catheter, have been proposed as rescue treatments. These procedures may allow the rescue of the catheter with a success rate of 70-100%. Therefore, in case of refractory exit-site/tunnel infection, a mini-invasive surgical revision should be considered before removing the catheter.

ISPD Catheter-related Infection Recommendations: 2023 Update

Peritoneal dialysis (PD) catheter-related infections are important risk factors for catheter loss and peritonitis. The 2023 updated recommendations have revised and clarified definitions and classifications of exit site infection and tunnel infection. A new target for the overall exit site infection rate should be no more than 0.40 episodes per year at risk. The recommendation about topical antibiotic cream or ointment to catheter exit site has been downgraded. New recommendations include clarified suggestion of exit site dressing cover and updated antibiotic treatment duration with emphasis on early clinical monitoring to ascertain duration of therapy. In addition to catheter removal and reinsertion, other catheter interventions including external cuff removal or shaving, and exit site relocation are suggested.

Simultaneous replacement and removal of the peritoneal catheter is effective in patients with refractory tunnel infections sustained by S. aureus

BACKGROUND

In tunnel infection (TI) refractory to medical therapy or in case of TI that occurs simultaneously with peritonitis, the removal of the peritoneal catheter has been proposed. This approach requires the interruption of peritoneal dialysis (PD) and the creation of a temporary vascular access. However, simultaneous removal and reinsertion of the PD catheter (SCR) represents another possible therapeutic approach.

METHODS

We analysed the outcome of 20 patients (10 men and 10 women, mean age 65.5 ± 16.3 years) treated by CAPD for a mean period of 24.3 ± 14.2 months who underwent to SCR for the treatment of TI unresponsive to medical therapy or TI that occurred simultaneously with peritonitis at Fondazione Ca' Granda Ospedale Maggiore Policlinico. All the patients restarted CAPD exchanges within 24 h from catheter placement.

RESULTS

SCR was successful in 80% (16/20) of the cases. In particular, SCR was effective in 100% (11/11) of the TI with or without associated peritonitis sustained by S. aureus. However, SCR failed in 57% (4/7) of TI associated with relapsing peritonitis and in one patient with TI secondary to Enterobacter. No early mechanical complications (within 3 months after SCR) occurred when CAPD was restarted.

CONCLUSIONS

SCR of the PD catheter through double-purse string technique represents an effective treatment for TI without or with simultaneously peritonitis sustained by S. aureus avoiding the patient the need for temporary hemodialysis and second surgical procedure. However, SCR could be contraindicated in case of relapsing peritonitis.

ISPD peritonitis guideline recommendations: 2022 update on prevention and treatment

Peritoneal dialysis (PD)-associated peritonitis is a serious complication of PD and prevention and treatment of such is important in reducing patient morbidity and mortality. The ISPD 2022 updated recommendations have revised and clarified definitions for refractory peritonitis, relapsing peritonitis, peritonitis-associated catheter removal, PD-associated haemodialysis transfer, peritonitis-associated death and peritonitis-associated hospitalisation. New peritonitis categories and outcomes including pre-PD peritonitis, enteric peritonitis, catheter-related peritonitis and medical cure are defined. The new targets recommended for overall peritonitis rate should be no more than 0.40 episodes per year at risk and the percentage of patients free of peritonitis per unit time should be targeted at >80% per year. Revised recommendations regarding management of contamination of PD systems, antibiotic prophylaxis for invasive procedures and PD training and reassessment are included. New recommendations regarding management of modifiable peritonitis risk factors like domestic pets, hypokalaemia and histamine-2 receptor antagonists are highlighted. Updated recommendations regarding empirical antibiotic selection and dosage of antibiotics and also treatment of peritonitis due to specific microorganisms are made with new recommendation regarding adjunctive oral N-acetylcysteine therapy for mitigating aminoglycoside ototoxicity. Areas for future research in prevention and treatment of PD-related peritonitis are suggested.

Maxillofacial-Derived Mesenchymal Stem Cells: Characteristics and Progress in Tissue Regeneration

Maxillofacial-derived mesenchymal stem cells (MFSCs) are a particular collective type of mesenchymal stem cells (MSCs) that originate from the hard and soft tissue of the maxillofacial region. Recently, many types of MFSCs have been isolated and characterized. MFSCs have the common characteristics of being extremely accessible and amazingly multipotent and thus have become a promising stem cell resource in tissue regeneration. However, different MFSCs can give rise to different cell lineages, have different advantages in clinical use, and regulate the immune and inflammation microenvironment through paracrine mechanisms in different ways. Hence, in this review, we will concentrate on the updated new findings of all types of MFSCs in tissue regeneration and also introduce the recently discovered types of MFSCs. Important issues about proliferation and differentiation in vitro and in vivo, up-to-date clinical application, and paracrine effect of MFSCs in tissue regeneration will also be discussed. Our review may provide a better guide for the clinical use of MFSCs and further direction of research in MFSC regeneration medicine.

Aspergillus peritonitis in peritoneal dialysis patients: A systematic review

Fungal peritonitis in patients undergoing peritoneal dialysis (PD) is very difficult to treat and is associated with significant morbidity and mortality. Among fungal pathogens, Aspergillus peritonitis presents a higher mortality rate when compared to Candida peritonitis and its identification as well as appropriate treatment remains a challenge for the physicians. We critical reviewed all published cases in literature of Aspergillus peritonitis in PD patients. The results showed that a total of 55 cases (51% males) of Aspergillus peritonitis in PD patients were reported from 1968 to 2019. Mean patient age was 49.54±19.63years and mean PD duration prior to fungal infection was 33.31±32.45months. Aspergillus fumigatus was isolated in 17/55 patients, Aspergillus niger in 15, Aspergillus terreus in 9, unidentified Aspergillus spp. in 6, Aspergillus flavus in 4, whereas sporadic cases of other Aspergillus spp. were reported. As far as predisposing factors are concerned, 75% of patients suffered from prior bacterial peritonitis receiving antimicrobial therapy. Initial antifungal treatment was intravenous and/or intraperitoneal administration of amphotericin B formulations monotherapy in 47.2% of patients or in combination with fluconazole in 13.2%, or with itraconazole in 13.2%, or with caspofungin in 3.8%, or with ketoconazole or with 5-FC in 1.9%, each. Peritoneal catheter removal was performed in 85.5% of cases. Mortality rate was 38.2%, while 81.8% of the survived patients switched to hemodialysis. Conclusively, Aspergillus peritonitis diagnosis can be difficult, due to unspecific symptoms. Early treatment with appropriate antifungal agents can be determinant for patient prognosis. Despite appropriate treatment, reported mortality remains high.

Reviews and Original Articles

The recommendations provided in this document represent a distillation of various experiences, as well as data obtained from published studies in the setting of substantial changes in antibiotic sensitivity. It is hoped that this revised compilation will provide a basis upon which future developments and advances can be made in the therapeutic approach to infectious complications of peritoneal dialysis.

Colonization-Resistant Antimicrobial-Coated Peritoneal Dialysis Catheters: Evaluation in a Newly Developed Rat Model of Persistent Pseudomonas Aeruginosa Peritonitis

Objective

Development of a rat model of persistent peritonitis and evaluation of the ability of liposomal ciprofloxacin hydrogel-coated silicone to resist colonization.

Design

A newly developed model of persistent Pseudomonas aeruginosa peritonitis to compare the ability of liposomal ciprofloxacin hydrogel (LCH)-coated silicone versus plain silicone for resistance to bacterial colonization.

Animals

Male Sprague–Dawley rats.

Results

Inoculating the peritoneum of rats with 1 mL 0.5% agar containing 106 colony-forming units (cfu)/mL P. aeruginosa in the presence of a plain silicone coupon resulted in persistent peritonitis for at least 7 days. Plain silicone coupons in all 40 rats were colonized (median 2.54 × 103 cfu/cm2; range 5.0 × 101 – 1.0 × 106 cfu/cm2) and peritoneal washings were consistently culture-positive. In contrast, the LCH coupons removed after 7 days from the 40 test rats were sterile, as were the peritoneal washings, and there was no evidence of peritonitis. Blood cultures were negative in both groups.

Conclusions

Liposomal ciprofloxacin hydrogel-coated silicone resists colonization in this rat model of persistent P. aeruginosa peritonitis.

Treatment Recommendations 1993 Update

In conclusion, the recommendations provided in this document represent a distillation of various experiences, as well as data obtained from published studies. It is hoped that this compilation will provide a basis upon which future developments and advances can be made in the therapeutic approach to infectious complications of peritoneal dialysis.

Chronic Tunnel Infections in Children: Removal and Replacement of the Continuous Ambulatory Peritoneal Dialysis Catheter in a Single Operation

Objective

Chronic tunnel infections often necessitate the removal of the continuous ambulatory peritoneal dialysis (CAPD) catheter. Most published studies advocate postponing the insertion of a new catheter for several weeks. For young children it will be particularly difficult to wait this length of time, since vascular access may be cumbersome, and hemodialysis may not be well tolerated. The present study describes the results of the simultaneous removal and replacement of the CAPD catheter. .Design: Twenty-three Toronto Western Hospital II catheters were inserted in 17 children because of infectious complications (21 chronic tunnel infections; 2 recurrent peritonitis) in a single operation under appropriate antibiotic prophylaxis. The new catheter was inserted at the contralateral side of the abdomen with the deep cuff in the midline, using the same entrance to the peritoneal cavity. Dialysis was resumed immediately after the operation.

Setting

A university pediatric dialysis unit.

Patients

Seventeen children (mean age 3.7 years; range 1.0–8.5 years) were studied. In this group 23 catheters were replaced.

Results

In four cases a relapse of the tunnel infection was observed within 3 months. All other cases remained free of infection for a period of at least 6 months. The main causative microorganism was Staphylococcus aureus (15 occurrences).

Conclusion

It is not necessary to interrupt peritoneal dialysis for the replacement of a CAPD catheter because of infectious complications.

Treatment of Refractory Pseudomonas Aeruginosa Exit-Site Infection by Simultaneous Removal and Reinsertion of Peritoneal Dialysis Catheter

Background

Patients on continuous ambulatory peritoneal dialysis (CAPD) with Pseudomonas aeruginosa exit-site infection (ESI) refractory to antibiotic treatment often require replacement of their peritoneal dialysis catheter (PDC). The optimal interval between removal and reinsertion of the PDC is not known. There are relatively few data on the feasibility of simultaneous removal and reinsertion of dialysis catheters for the treatment of P. aeruginosa ESI.

Methods

We retrospectively reviewed the short- and long-term outcomes of all CAPD patients who had undergone simultaneous removal and reinsertion of their PDC for the treatment of refractory P. aeruginosa ESI in our hospital between January 1994 and December 2003. During the operation, the old catheter was removed first and a new catheter was inserted into the opposite side of the abdomen. All patients received 7 days of antibiotic therapy postoperatively. CAPD was resumed after 2 weeks of intermittent peritoneal dialysis.

Results

Over a 10-year period, 37 CAPD patients underwent the operation. Mean age of the patients was 59.5 ± 10.9 years. The interval between the diagnosis of ESI and the operation was 16.7 ± 6.9 weeks. The patients received 7.6 ± 2.5 weeks of antibiotic treatment before the procedure. Early postoperative complications were uncommon. None of the patients developed ESI within 4 weeks after the operation. At 1 year after the operation, 3 patients (8%) had developed recurrence of P. aeruginosa ESI 24 – 40 weeks postoperatively. Peritonitis due to P. aeruginosa was not observed.

Conclusions

We conclude that simultaneous removal and reinsertion of the PDC is feasible in eradicating refractory ESI due to P. aeruginosa. This procedure alleviates the need for temporary hemodialysis and allows continuation of peritoneal dialysis.

Peritoneal Catheters and Exit-Site Practices toward Optimum Peritoneal Access: 1998 Update

The peritoneal catheter is the PD patient's lifeline. Advances in catheter knowledge have made it possible to obtain access to the peritoneal cavity safely and to maintain access over an extended period of time. Catheter-related infections remain a major problem, solutions for which are being actively researched. Nevertheless, the successful outcome of a catheter is very much dependent on meticulous care and attention to detail. Adherence to the principles of catheter insertion and subsequent management and care remain the cornerstone of successful PD access. The guidelines provided in this publication represent a consensus view based on studies from the literature and opinions of experts in this field; it is hoped that implementation of these guidelines will improve catheter-related outcomes and, therefore, enhance patient care.

Exit-Site Relocation: A Novel, Straightforward Technique for Exit-Site Infections

Background

Exit-site infection (ESI) and tunnel infection (TI) of the peritoneal dialysis (PD) catheter are significant causes of catheter or even method loss as well as patient morbidity. Among the methods that have been in use thus far, the removal and replacement of the catheter often needs to be followed by switching temporarily to hemodialysis, whereas catheter splicing or unroofing of the tunnel tract and shaving/removal of the superficial catheter cuff have not gained universal acceptance thus far.

Methods

We treat chronic ESI with exit-site relocation under local anesthetic with removal of the external cuff. For the purposes of this study, we conducted a retrospective cohort analysis of all exit-site relocations performed using that technique over a 5-year period.

Results

Twenty-seven patients (16 male, mean age 58 years, range 23 – 81 years) with chronic ESI underwent exit-site relocation under local anesthetic as a day-case procedure. Follow-up was 47.5 ± 22.4 months (range 10.8 – 79.4 months). No dialysate leaks occurred following the procedure. Peritoneal dialysis was resumed immediately. The procedure resulted in long-term resolution of the infection in 20 of the 27 patients (74%). In 7 patients (26%), the catheter had to be removed eventually, either because of ESI recurrence (5 patients) or TI (2 patients), which in 2 cases was subsequently complicated by PD peritonitis, and the patients were switched to hemodialysis.

Conclusion

The technique described herein is a safe, straightforward, and effective method for the treatment of chronic ESI while the patient remains on PD and avoids switching to hemodialysis.

Outcomes following peritoneal dialysis catheter removal with reinsertion or permanent transfer to haemodialysis

INTRODUCTION

Long-term use of peritoneal dialysis catheter is associated with complications such as infection and malfunction, necessitating removal of catheter with subsequent reinsertion or permanent transfer to haemodialysis. This study aims to investigate the outcome in patients who underwent reinsertion.

METHODS AND MATERIALS

A single-centre retrospective study was performed in Singapore General Hospital for all adult incident peritoneal dialysis patients between January 2011 and January 2016. Study data were retrieved from patient electronic medical records up till 1 January 2017.

RESULTS

A total of 470 patients had peritoneal dialysis catheter insertion with median follow-up period of 29.2 (interquartile range = 16.7-49.7) months. A total of 92 patients required catheter removal. Thirty-six (39%) patients underwent catheter reinsertion. The overall technique survival at 3 and 12 months were 83% and 67%. Median time to technique failure of the second catheter was 6.74 (interquartile range = 0-50.2) months. The mean survival for patients who converted to haemodialysis and re-attempted peritoneal dialysis was comparable (54.9 ± 5.5 vs 57.3 ± 3.6 months; p = 0.75). Twelve (13%) patients had contraindication for peritoneal dialysis and were excluded from analysis. Of 11 patients who required catheter removal due to malfunction, 7 (64%) underwent catheter reinsertion and 6 (86%) patients ultimately converted to haemodialysis during study period. Of the 69 patients who had catheter removal due to infection, 29 (42%) underwent catheter reinsertion and 8 (28%) patients eventually converted to haemodialysis during the study period.

CONCLUSION

Patient survival was comparable between patients who re-attempted peritoneal dialysis and patients who transferred to haemodialysis. Patients who had previous catheter removal due to infections had favourable technique survival than those due to catheter malfunction.

Simultaneous Removal And Reinsertion of the PD Catheter in Relapsing Peritonitis

Background:Relapsing peritonitis in peritoneal dialysis (PD) is associated with lower cure rates and more hemodialysis (HD) transfers, as catheter removal is recommended in these situations. The aim of our study was to evaluate the continuation of PD without perioperative transfer to HD in patients who underwent a simultaneous catheter removal and replacement for relapsing peritonitis.Methods:This was a retrospective monocentric study. Patients with simultaneous catheter removal and replacement for relapsing peritonitis or peritonitis at high risk of relapse (fungal or Pseudomonas infection) between 1 January 2007 and 31 December 2016 were included. The events of interest were the continuation of PD without perioperative transfer to HD, postoperative complications, new infection with the same organism, and technique survival.Results:Of the 271 incident patients in PD during this period, 11 had a simultaneous catheter removal and replacement for relapsing peritonitis (8) or high risk of relapse peritonitis (3). Eight (72.7%) patients pursued PD without transfer to HD. Six infections were due to microorganisms other than gram-positive cocci. At 1 year, 7 (63.6%) of the 11 patients were still on PD. After the surgery, there were no peritonitis or catheter-related infections caused by the same organism.Conclusion:Simultaneous catheter removal and replacement for peritonitis appears to be an effective procedure for maintaining patients on PD.

Peritoneal Dialysis Cuff-Shaving-A Salvage Therapy for Refractory Exit-Site Infections

Introduction:Cuff-shaving has been described as a salvage technique for refractory exit-site infections, with conflicting data regarding infection and catheter outcomes. We describe our experience with cuff-shaving as a rescue therapy for exit-site infections unresponsive to systemic therapy.Methods:We retrospectively reviewed patients who underwent cuff-shaving between January 2012 and June 2017. Refractory exit-site infection was defined as purulent discharge from the exit site with no clinical response after 3 weeks of systemic antibiotic treatment.Results:Fifty-three cuff-shavings were included, mean age was 53.4 ± 13.4 years, 26 patients were male. Median dialysis vintage was 29 months (interquartile range [IQR] 14.3 - 38), and 39 (73.6%) were on continuous ambulatory peritoneal dialysis (CAPD). The exit-site infection rate before cuff-shaving was 1.12 episodes per patient-year and the median time from infection to shaving was 52 days (IQR 35 - 76). The most frequent agents were Staphylococcus aureus (34%), Corynebacterium spp. (17%) and Pseudomonas aeruginosa (15%). Median follow-up was 9 months (IQR 1 - 18.5), during which time 35 catheters were removed, 5 due to non-infectious reasons. Using the Kaplan-Meier survival analysis, median catheter survival was 24 months (95% confidence interval [CI] 4.17 - 43.83). At 12 months, the probability of catheter survival was 54% and was not statistically different between gram-positive and gram-negative agents, although it was significantly shorter for fungal agents.Conclusion:Cuff-shaving is a feasible rescue therapy to treat refractory exit-site infections. In our experience, it allowed resolution of infections in a significant proportion of cases, except for fungal agents, and therefore extended catheter survival time, besides being associated with a small rate of complications.

Reducing intra-abdominal pressure in peritoneal dialysis patients to avoid transient hemodialysis

Patients treated with peritoneal dialysis (PD) are often required to switch to hemodialysis (HD) temporarily when they develop abdominal wall hernias and dialysate leaks, peritonitis or undergo thoracic or abdominal surgeries. There are significant risks associated with incident hemodialysis including possible central venous catheter infections, thrombosis, and need for invasive procedures. Therefore, strategies to avoid temporary transfer to hemodialysis are desirable. The increased intra-abdominal pressure associated with PD is largely responsible for the issues requiring withholding PD. However, the high intra-abdominal pressure, due to dialysate and body position, can be minimized by making changes to the peritoneal dialysis prescription. The lower intra-abdominal pressure may allow dialysate leaks, hernia repairs, and abdominal incisions time to heal as well as to facilitate earlier resumption of PD after catheter replacement. These strategies help to decrease morbidity and minimize cost to the health care system associated with modality switches and its complications.

Simultaneous Catheter Replacement for Infectious and Mechanical Complications Without Interruption of Peritoneal Dialysis

♦

BACKGROUND

Conventional management for peritoneal dialysis (PD)-related infectious and mechanical complications that fails treatment includes catheter removal and hemodialysis (HD) via a central venous catheter with the end result that the majority of patients will not return to PD. Simultaneous catheter replacement (SCR) can retain patients on PD by avoiding the scenario of staged removal and reinsertion of catheters. The aim of this study was to evaluate a protocol for SCR without interruption of PD. ♦

METHODS

Clinical outcomes were analyzed for 55 consecutive SCRs performed from 2002 through 2012 and followed through 2013. ♦

RESULTS

Simultaneous catheter replacements were performed for 28 cases of relapsing peritonitis, 12 cases of tunnel infection, and 15 cases of mechanical catheter complications. All cases for peritonitis and tunnel infection and 80% for mechanical complications continued PD on the day of surgery using a low-volume, intermittent automated PD protocol. Systemic antibiotics were continued for 2 weeks postoperatively (up to 4 weeks for Pseudomonas). Simultaneous catheter replacement was performed as an outpatient procedure in 89.1% of cases. Only 1 of 55 procedures was complicated by peritonitis within 8 weeks. No catheter losses occurred during this postoperative timeframe. Long-term, SCR enabled a median technique survival of 5.1 years. ♦

CONCLUSIONS

In most instances, SCR can be safely performed without interruption of PD for selected cases of peritonitis and tunnel infection and for mechanical catheter complications. The procedure spares the patient from a central venous catheter, a shift to HD, the psychological ordeal of a change in dialysis modality, and a second surgery to insert a new catheter.

Outcomes of peritoneal dialysis catheter reinsertion: does the cause of initial removal matter?

PURPOSE

In this study, we aimed to compare patient and technique survival between the patients, in whom peritoneal dialysis (PD) catheter was removed due to severe peritonitis and then it was reinserted, and those, in whom PD catheter was removed due to non-peritonitis causes and then it was reinserted.

METHOD

Sixty-two patients, in whom PD catheter was reinserted surgically, were retrospectively analyzed in this cohort study. Group 1 consisted of 27 patients in whom PD catheter was removed due to severe peritonitis, whereas Group 2 consisted of 35 patients in whom PD catheter was removed due to non-peritonitis causes.

RESULTS

There was no significant difference between Group 1 and Group 2 in terms of the estimation of overall patient survival [43 months (95 % CI 43.6-83.7) versus 80 months (95 % CI 52.8-107.3, p 0.362]. Similarly, there was no significant difference between Group 1 and Group 2 in terms of the estimation of overall technique survival [82 months (95 % CI 0-166.0) versus 31 months (95 % CI 9.7-52.3), p 0.346].

CONCLUSION

Our results suggest that there was no significant effect of causes of PD catheter removal (peritonitis vs. non-peritonitis) on the outcomes of PD treatment.

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.

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.

Peritoneal dialysis catheter replacement: "save the patient and not the catheter"

A 63-year-old man on ambulatory peritoneal dialysis (APD) developed peritonitis with Enterococcus faecalis, treated with 2 g intraperitoneal (IP) vancomycin, with rapid clearing of the effluent white blood cells, but persistence of positive cultures. Vancomycin was redosed on day 8 (2 g IP), and then weekly. Gentamicin 140 mg IP loading dose, followed by 40 mg IP once a day was added after cultures were still positive at 2 weeks. The two drugs were continued for six additional weeks. Although the patient was asymptomatic, the effluent cultures continued to grow E. faecalis and the catheter was replaced 2 months after the onset of peritonitis. There was no evidence of either tunnel infection or intra-abdominal abscess. Refractory peritonitis is defined as continuation of peritonitis after 5 days of appropriate therapy. This patient had persistently positive cultures but quickly became asymptomatic and signs of inflammation resolved readily. The most likely etiology appears to have been colonization of the slime layer of the intra-abdominal portion of the catheter with the organism. The vancomycin dosing schedule may have played a role in the persistently positive cultures. A recent pharmacokinetic study suggested that patients on APD require 35 mg/kg IP of vancomycin as a loading dose, followed by 15 mg/kg IP once a day, given in a long day exchange. Simultaneous placement and removal as a single procedure was successful in this patient and can be done safely in patients whose effluent white blood cell count (WBC) is less than 100/mm3. Most patients can then be subsequently managed by doing supine dialysis (using a cycler) with decreased exchange volumes and a dry abdomen until healing occurs (usually 1-2 weeks). In this way hemodialysis can be avoided. By minimizing the effect on the patient's lifestyle, the patient is more likely to agree to a catheter exchange.

Infections in patients undergoing peritoneal dialysis

Considering experience acquired in the past years, it seems as though physicians have reached a plateau in the frequency of peritonitis. A peritonitis rate of 1 every 2 patient years may be acceptable. Further reduction of this peritonitis rate will require inordinately large efforts on all fronts. One will have to consider what are the acceptable costs and risks of peritonitis in patients on peritoneal dialysis. New developments in catheter technology, improved connections, better understanding of patient selection and training programs, improved diagnostic and therapeutic methods in the management of peritonitis, and understanding of the infectious and immune processes are eagerly awaited developments.

Dialysis access related infections

Infection is a common cause of morbidity and mortality in end-stage renal disease patients. Unintentional pathogens are introduced into an immunocompromised host during hemodialysis and peritoneal dialysis by means of the access (arteriovenous fistula, arteriovenous graft, central venous catheter, or peritoneal dialysis catheter). Gram positive organisms are most common with Staphylococcus aureus and coagulase negative Staphylococcus predominating. Preventive measures are mandatory and the key to decreasing infection rates.

Peritoneal dialysis. Prevention and control of infection

In spite of the reduction in peritonitis and catheter-related infection rates in patients undergoing peritoneal dialysis, these infections remain major sources of morbidity and transfer to haemodialysis. Touch contamination at the time of doing the exchanges is still a major cause of peritonitis and leads to Gram-positive organisms (coagulation-negative staphylococcus) being the most common pathogens. Newer exchange techniques have reduced this incidence but the more serious pathogens (Staphylococcal aureus, pseudomonas and fungi) remain a major problem. Treatment has to be immediate, and hence empirical, giving adequate cover for both Gram-positive and Gram-negative organisms. The use of vancomycin as an initial antibacterial has been discontinued because of the problem of vancomycin-resistant enterococcus. Recent guidelines advocate the use of a first generation cephalosporin combined with ceftazidime (if the urine output is >100 ml/day) or an aminoglycoside in anuric patients. Subsequent therapy changes are made upon bacterial isolation and sensitivities. Vancomycin is reserved for methicillin-resistant staphylococcus. Peritoneal catheter-related infections (exit site and tunnel) are predominantly caused by S. aureus and pseudomonal organisms and can be difficult to eradicate. Tunnel infections invariably involve the catheter dacron cuffs and therefore are more likely to lead to peritonitis; in this situation catheter removal is the treatment of choice. Treatment of exit-site infections is with oral antibacterials (penicillinase-resistant penicillins, cefalexin). Vancomycin is avoided if possible. The identification that nasal carriage of S. aureus predisposes to exit-site and tunnel infections has led to prophylactic regimens to combat this problem. Mupirocin applied at the exit site leads to a reduction in catheter-related infections and peritonitis.

Expanded CD14+ CD16+ monocyte subpopulation in patients with acute and chronic infections undergoing hemodialysis

Infections are frequent complications in end-stage renal failure patients undergoing hemodialysis (HD), and peripheral blood monocytes are important cells in host defense against infections. The majority of circulating monocytes express high levels of lipopolysaccharide receptor antigen CD14 and are negative for the immunoglobulin Fcgamma receptor type III (CD16). We studied the occurrence of a minor subpopulation coexpressing low levels of CD14 together with CD16 in HD patients. In healthy controls CD14+ CD16+ monocytes account for 8% +/- 4% of CD14+ monocytes, with an absolute number of 29 +/- 14 cells/microl. In stable HD patients the CD14+ CD16+ subpopulation was significantly elevated (14% +/- 3%, or 66 +/- 28 cells/microl), while the number of CD14(++) monocytes (monocytes strongly positive for CD14) remained constant. In HD patients suffering from chronic infections a further rise in CD14+ CD16+ monocytes was observed (128 +/- 71 cells/microl; P < 0.01) such that this subpopulation constituted 24% of all blood monocytes. In contrast, numbers of CD14++ cells did not change compared to those for stable HD patients, indicating that the CD14+ CD16+ monocyte subpopulation was selectively expanded. During acute infections the CD14+ CD16+ cell subpopulation always expanded. A whole-blood assay revealed that CD14+ CD16+ monocytes exhibited a higher phagocytosis rate for Escherichia coli bacteria than CD14++ monocytes, underlining their role during host defense. In addition, CD14+ CD16+ monocytes expressed higher levels of major histocompatibility complex (MHC) class II antigens (HLA-DR, -DP, and -DQ) and equal amounts of MHC class I antigens (HLA-ABC). Thus, CD14+ CD16+ cells constitute a potent phagocytosing and antigen-presenting monocyte subpopulation, which is expanded during acute and chronic infections commonly observed in chronic HD patients.

Simultaneous removal and replacement of infected peritoneal dialysis catheters

Infection is an important complication of peritoneal dialysis that often limits technique survival. Recurrent episodes of peritonitis caused by the same organism may be the result of catheter infection, necessitating removal. We performed 34 single-step catheter replacement procedures in children and young adults for recurrent peritonitis or refractory exit site and tunnel infections. The success rate of the procedure was high (85%), with rare instances of intraoperative contamination. The presence of Staphylococcus aureus infection or exit site and tunnel infection were not risk factors for worse outcome. All patients continued on peritoneal dialysis through catheter change without requiring interval hemodialysis. Eighteen peritoneal dialysis catheters were replaced in a staged procedure with an interval off peritoneal dialysis. There was one early reinfection of the new catheter. Patients with Pseudomonas sp infections were more likely to be treated with a staged procedure; S aureus infections were equally likely to be managed by staged or simultaneous catheter removals. Simultaneous removal and replacement of infected peritoneal dialysis catheters is an effective management strategy when compared with two-step catheter replacements.

Peritoneal catheter exit-site and tunnel infections

Peritoneal catheter exit-site and tunnel infections may lead to peritonitis and catheter loss. Exit-site infections are diagnosed when there is pericatheter erythema and/or purulent drainage. Staphylococcus aureus is the most common cause of both exit-site and tunnel infections. S. aureus nasal carriage is an important risk factor for S. aureus catheter infections. Few other risk factors for catheter infections have been identified. Treatment of catheter infections consists of antibiotic therapy, often prolonged, as well as intensification of exit-site care. Refractory cases may resolve with revision of the tunnel and exit-site with removal of the superficial cuff, but some patients undergoing this procedure will develop peritonitis. Once peritonitis develops from a tunnel infection, the catheter should be replaced. Research on prevention of catheter infections has focused on three areas: antibiotic prophylaxis, exit-site care, and new catheter designs. Several antibiotic protocols, including intranasal mupirocin, cyclical oral rifampin, and exit-site mupirocin, are effective in decreasing S. aureus catheter infections and should be used more widely. New catheter designs may, in the future, prove to further diminish catheter infection and loss, but there are insufficient data at this time to show superiority of one catheter over another.