Potential clinical value of catheters impregnated with antimicrobials for the prevention of infections associated with peritoneal dialysis

INTRODUCTION

Peritoneal dialysis (PD) is a widely used dialysis modality, which offers the advantage of being a home therapy but is associated with a risk of potentially serious infections, including exit site infection, catheter tunnel infection, and peritonitis that may result in morbidity, technique failure, and increased mortality. Catheters impregnated with antimicrobials hold promise as a novel technique to reduce PD associated infections.

AREAS COVERED

We describe PD modalities, catheters, technique, complications, and the microbiology of associated infections, as well as standard measures to reduce the risk of infection. A novel technique for the impregnation of silicone devices with antimicrobial agents has been used to produce antimicrobial impregnated ventricular shunt catheters with proven clinical efficacy that have now been adopted as the standard of care to reduce neurosurgical infections. Using the same technology, we have developed PD and urinary catheters impregnated with sparfloxacin, triclosan, and rifampicin. Safety and tolerability have been demonstrated in urinary catheters, and a similar study is planned in PD catheters.

EXPERT OPINION

Catheters impregnated with antimicrobials offer a simple technique to reduce PD associated infections and thereby enable more people to enjoy the advantages of PD. Clinical trials are needed to establish efficacy.

Extended antibiotic therapy for the prevention of relapsing and recurrent peritonitis in peritoneal dialysis patients: a randomized controlled trial

Background

Relapsing and recurrent peritonitis episodes are major causes of technique failure in peritoneal dialysis (PD). We examined the efficacy of extended antibiotic therapy for the prevention of relapsing and recurrent peritonitis.

Methods

From February 2016 to November 2018 we recruited 254 PD patients who fulfilled the diagnostic criteria for PD peritonitis. They were randomized to a standard group, with the duration of intraperitoneal (IP) antibiotic treatment following the International Society for Peritoneal Dialysis (ISPD) guideline according to the causative microorganisms, and an extended group, with 1 extra week of IP antibiotics. The primary endpoint was relapsing, recurrent or repeat peritonitis episodes within 6 months.

Results

The primary endpoint developed in 36 and 29 patients of the extended and standard groups, respectively (28.3% versus 22.8%; P = 0.34). The rate of complete cure, without relapsing, recurrent or repeat peritonitis within 6 months, was 63.8 and 69.3% for the extended and standard groups, respectively (P = 0.35). Repeat peritonitis episodes were more common in the extended than the standard group (15.0% versus 5.5%; P = 0.013).

Conclusions

In patients with PD-related peritonitis, extending the antibiotic therapy for 1 extra week beyond the ISPD protocol should not be recommended. Extending the treatment does not reduce the risk of relapsing or recurrent peritonitis episodes but rather is associated with a higher risk of repeat peritonitis episodes.

Antimicrobial d-Peptide Hydrogels

Biofilms are widely involved in human lives, such as in medical infection, environmental remediation, and industrial processes. However, the control of the biofilm has still been a challenge because of its strong drug resistance. Here, we designed and synthesized an amphipathic antimicrobial peptide (Ac-^DK^DH^DH^DQ^DK^DL^DV^DF^DF^DA^DK-NH₂ (KKd-11)) that was composed of d-amino acids (DAAs). KKd-11 was found to self-assemble into a hydrogel with an improved long-term antimicrobial ability and a better antiprotease activity as compared to the hydrogel formed by Ac-^LK^LH^LH^LQ^LK^LL^LV^LF^LF^LA^LK-NH₂ (KK-11). Our results indicated that KKd-11 was not only able to inhibit the formation of biofilms but also could effectively damage preformed mature biofilms and kill the bacteria within the biofilms. Besides, cell viability assays indicated that the KKd-11 peptide had very good biocompatibility. We think d-peptide hydrogels may have great potential in the treatment of biofilm-induced infections.

Repeat Peritoneal Dialysis Exit-Site Infection: Definition and Outcomes

Background:The most common complication of peritoneal dialysis (PD) is infection. Despite this, there are no clear guidelines for the management of repeat exit-site infection (ESI), and best practice is not known. We describe our unit's experience of repeat ESI and clinical outcomes in this cohort.Methods:Retrospective case note review of all PD patients with positive ESI swabs at our center between 1 January 2012 and 1 January 2018. Patients were included in the study if they had 2 or more ESI with the same organism within a 12-month period and an initial positive response to antibiotic therapy.Results:Overall, 31 of 248 patients had repeat ESI. The 2 most common causative organisms were Staphylococcus aureus (n = 16, 52%) and Pseudomonas aeruginosa (n = 10, 32%). Twenty (65%) patients developed subsequent peritonitis. The infection resolved with further antibiotics alone in 10 (32%) patients and in 6 patients after PD catheter exchange. The PD catheter was removed in 16 (52%) patients (including 5 after an initial catheter exchange) requiring transfer to hemodialysis (HD). Six (19%) patients died within 12 months of repeat ESI. Both repeat Pseudomonas aeruginosa and Staphylococcus aureus infections were associated with high rates of dialysis modality change (70% and 50%, respectively).Conclusion:We have developed the first definition for repeat ESI. Repeat ESI is clinically important and results in significant morbidity and mortality. Following repeat ESI, peritonitis rates are high and a significant number of patients switch dialysis modality. Studies are needed to determine whether interventions such as early catheter exchange would improve outcomes.

Potential causes of black-stained peritoneal dialysis tubing: an analysis from nurse practitioner's prospect

Background

Continuous Ambulatory Peritoneal dialysis (CAPD) has been promoted to be the main method of treatment for Thai End-Stage Renal Disease (ESRD) patients; however, a national survey of dialysis centers reported an annual incidence of black-stained particle of 57.6 per 1,000 CAPD cases. The objective of this study was to identify potential causes of the stain in the nurse practitioners’ prospect.

Findings

This study applied three-round Delphi technique. In the first round, the questionnaire was sent to 127 nurses in all dialysis centers. Their responses were analyzed to come up with an anonymous summary, which was presented in the second and third round of the survey among 80 and 200 nurses. The response rates of the three rounds of Delphi were 57.5%, 81.3%, and 75.0%, respectively. Nurses consistently believed that the contamination was caused by spilled-out povidone-iodine solution during transfer set change. Other potential causes were previous peritonitis, inadequate dialysis, low serum albumin, transfer set soaking with antiseptics, patient history of diabetes, dressing technique, and existence of dry abdomen period.

Conclusions

Black-stained particle is a common contamination of dialysis tube in CAPD patients. This study proposed some potential determinants, most of which were relevant to care process.

Clinical causes of inflammation in peritoneal dialysis patients

Inflammation at both systemic and local intraperitoneal levels commonly affects peritoneal dialysis (PD) patients. Interest in inflammatory markers as targets of therapeutic intervention has been considerable as they are recognised as predictors of poor clinical outcomes. However, prior to embarking on strategies to reduce inflammatory burden, it is of paramount importance to define the underlying processes that drive the chronic active inflammatory status. The present review aims to comprehensively describe clinical causes of inflammation in PD patients to which potential future strategies may be targeted.

Morphological analysis of biofilm of peritoneal dialysis catheter in refractory peritonitis patient

A 66-year-old man undergoing peritoneal dialysis (PD) was admitted to our hospital for treatment of PD-related peritonitis. Culture of the PD fluid revealed the presence of Citrobacter freundii, and therapy with ceftazidime was started intraperitoneally. The cell count in PD fluid slowly decreased over time during the first 2 weeks of treatment, but increased again on the 14th hospital day. A second culture of the PD fluid revealed the presence of Enterococcus species. A switch in antibiotic therapy to vancomycin did not improve the cell count in the PD fluid. A third culture of the PD fluid revealed the presence of Stenotrophomonas maltophilia. The PD was discontinued and the catheter removed on the 28th hospital day. Examination of the catheter revealed that the inner tip was coated with a fibrous sheet of cells, suggesting biofilm formation. Following catheter removal, the patient was administered intravenous ciprofloxacin, and the inflammatory reaction started to disappear immediately and had completely disappeared after 1 week of treatment. Microscopic analysis of the fibrous structure on the catheter revealed multiple layers of various inflammatory cells. Immunostaining revealed the presence of CD44-positive polynuclear cells, indicating neutrophils, facing the catheter lumen. CD68-positive cells, indicating macrophages, were observed in the following layer, and keratin-positive cells, indicating peritoneal mesothelial cells, were present at the bottom of the structure. Based on the immediate improvement of PD-related peritonitis after catheter removal, we presumed that this biofilm contributed to the intractability of the patient's peritonitis. Morphological analysis of catheter revealed that both the mesothelial cells and the various inflammatory cells may have contributed to biofilm development.

Pseudomonas peritonitis in Australia: predictors, treatment, and outcomes in 191 cases

BACKGROUND AND OBJECTIVES

Pseudomonas peritonitis is a serious complication of peritoneal dialysis. To date, there as been no comprehensive, multicenter study of this condition.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

The predictors, treatment, and clinical outcomes of Pseudomonas peritonitis were examined by binary logistic regression and multilevel, multivariate Poisson regression in all Australian PD patients in 66 centers between 2003 and 2006.

RESULTS

A total of 191 episodes of Pseudomonas peritonitis (5.3% of all peritonitis episodes) occurred in 171 individuals. Its occurrence was independently predicted by Maori/Pacific Islander race, Aboriginal/Torres Strait Islander race, and absence of baseline peritoneal equilibration test data. Compared with other organisms, Pseudomonas peritonitis was associated with greater frequencies of hospitalization (96 versus 79%; P = 0.006), catheter removal (44 versus 20%; P < 0.001), and permanent hemodialysis transfer (35 versus 17%; P < 0.001) but comparable death rates (3 versus 2%; P = 0.4). Initial empiric antibiotic choice did not influence outcomes, but subsequent use of dual anti-pseudomonal therapy was associated with a lower risk for permanent hemodialysis transfer (10 versus 38%, respectively; P = 0.03). Catheter removal was associated with a lower risk for death than treatment with antibiotics alone (0 versus 6%; P < 0.05).

CONCLUSIONS

Pseudomonas peritonitis is associated with high rates of catheter removal and permanent hemodialysis transfer. Prompt catheter removal and use of two anti-pseudomonal antibiotics are associated with better outcomes.

Antibiofilm approaches: prevention of catheter colonization

Bacteria frequently attach to medical devices such as intravascular catheters by forming sessile multicellular communities known as biofilms, which can be the source of persistent infections that are recalcitrant to systemic antibiotic therapy. As a result of this persistence, a number of technologies have been developed to prevent catheter-associated biofilm formation. Whereas the most straightforward approaches focus on impregnating catheter material with classical antimicrobial agents, these approaches are not universally effective, thereby underscoring the need for more potent and more sophisticated approaches to the prevention of catheter-related biofilm infections.