Catheter-related infections: A Scandinavian observational study on the impact of a simple hygiene insertion bundle

Central venous catheter tip colonization and associated bloodstream infection in patients with severe burns under routine catheter changing

BACKGROUND

Although routine changing of central venous catheters (CVCs) is commonly performed in patients with severe burns, information on pathogen colonization of the CVC tip and associated bloodstream infections (BSIs) is limited in those patients.

METHODS

The medical records of 214 patients with severe burns who underwent routine CVC changing at 7-day intervals and their results of 686 pairs of CVC tips and concurrent blood cultures were retrospectively reviewed to evaluate the CVC colonization rate and associated BSI pathogens.

RESULTS

Of the 686 CVCs, 137 (20.0%) were colonized by pathogens, and 81 (59.1%) of them had BSIs caused by the same pathogen. Nonflame burn (P = .002), total body surface area burn ≥30% (P = .004), femoral catheterization (P = .001), CVC changing during pre-existing BSI (P < .001), and renal replacement therapy (P = .017) were associated with catheter-related BSI in the multivariate analysis. Most BSIs were caused by Gram-negative bacteria (most commonly Acinetobacter baumannii, Klebsiella pneumoniae, and Pseudomonas aeruginosa).

CONCLUSIONS

The CVC colonization rate in patients with severe burns and routine CVC changing was not high. Lengthening the CVC duration might be attempted in patients at a lower risk of catheter-related BSI although further prospective studies are necessary.

Novel Antibacterial Agents SAAP-148 and Halicin Combat Gram-Negative Bacteria Colonizing Catheters

The antibiotic management of catheter-related infections (CRIs) often fails owing to the emergence of antimicrobial-resistant strains and/or biofilm/persister apparitions. Thus, we investigated the efficacy of two novel antimicrobial agents, i.e., the synthetic peptide SAAP-148 and the novel antibiotic halicin, against Gram-negative bacteria (GNB) colonizing catheters. The antibacterial, anti-biofilm, and anti-persister activities of both agents were evaluated against Acinetobacter baumannii, Escherichia coli, and Klebsiella pneumoniae strains. The enrolled strains were isolated from catheters and selected based on their resistance to at least three antibiotic classes and biofilm formation potential. Furthermore, the hemolysis and endotoxin neutralization abilities of these agents were explored. The bactericidal activity of both agents was reduced in urine and plasma as compared to buffered saline. In a dose-dependent manner, SAAP-148 and halicin reduced bacterial counts in 24 h preformed biofilms on silicone elastomer discs and eliminated persisters originating from antibiotic-exposed mature 7-day biofilms, with halicin being less effective than SAAP-148. Importantly, SAAP-148 and halicin acted synergistically on E. coli and K. pneumoniae biofilms but not on A. baumannii biofilms. The peptide, but not halicin, decreased the production of IL-12p40 upon exposure to UV-killed bacteria. This preliminary study showed that SAAP-148 and halicin alone/in combination are promising candidates to fight GNB colonizing catheters.

Sustained low catheter related infection (CRI) incidence in an observational follow-up study of 9924 catheters using automated data scripts as quality assurance for central venous catheter (CVC) management

Background

To maintain a low incidence of Catheter Related Infections (CRI) and Catheter Related Bloodstream Infections (CRBSI), continuous follow-up studies on catheter management are necessary. The aims of the present study were to investigate the incidence of catheter tip colonisation, CRI and CRBSI in the Region, to further explore the feasibility of automatic data collection and to investigate associations between independent variables and CRI.

Methods

Data from electronic patient charts on all documented central venous catheter (CVC) insertions from multiple hospitals in southern Sweden, between March 2019 and August 2020, were automatically extracted. Multivariable regression analyses were used to identify associated risk factors.

Results

In total, 9924 CVC insertions were included. The prevalence of CRI and CRBSI were 0.7% (n = 74) and 0.02% (n = 20) with incidences of 1.2/1000 catheter days and 0.3/1000 catheter days, respectively.

Conclusions

We found a sustained low incidence of CRI and CRBSI in the Region. Catheter tips were less likely to be colonised when the subclavian route was used compared to the internal jugular route and male sex as well as increased number of catheter lumens were associated with both catheter tip colonisation and CRI. By using automated scripts, data extraction was efficient and feasible but also demonstrated that real-time quality assurance should be recommended, since this is superior to current standard.

Blood compatibility of widely used central venous catheters; an experimental study

An inserted central venous catheter (CVC) is considered foreign material by the inert host defence systems and induce inflammation and thrombus formation. The objective of this study was to evaluate blood compatibility of six commonly used CVCs. Three coated and three uncoated CVC materials were tested in a modified Chandler loop model. Each catheter material circulated in blood from ten different healthy volunteers for 1 h. Blood cell counts and measurements of the inert host defence systems were performed on blood samples from the loop. All the tested catheters demonstrated impact on blood cells, contact coagulation, the complement system, or inflammatory markers, although the impact varied significantly. Of the catheters we evaluated, the most unfavourable blood compatibility profile was found for the polyurethane CVC coated with chlorohexidine and silver sulfadiazine. The greatest variation in blood compatibility between test runs was noted for the silicone dialysis catheter. Poor blood compatibility should be taken seriously but given the experimental design of the current study the clinical significance remains to be evaluated.

Central venous catheter-related complications in hematologic patients: An observational study

BACKGROUND

The frequency of central venous catheter (CVC)-related complications in hematologic patients has previously been studied but some uncertainty remains. Therefore, this observational cohort study was designed primarily to investigate mechanical and infectious complications related to CVC insertion in hematologic patients and secondarily to identify factors associated with these complications.

METHODS

Documented data on CVC insertions in all adult hematologic patients who received a CVC from 2013 to 2019 at a University Hospital in Sweden were retrospectively collected.

RESULTS

A total of 589 CVC insertions in 387 patients were included. The prevalence of moderate and severe mechanical complications, predominantly comprising grades 2-4 bleeding, was 11%. Preprocedural coagulopathy, number of needle passes, and arterial puncture were all independently associated with grades 2-4 bleeding. The incidence of suspected catheter-related infections (sCRI) was 3.7/1000 catheter days. Higher body mass index and male gender were independently associated with sCRI.

CONCLUSIONS

Patients with hematologic malignancies have a high risk of both grades 2-4 bleeding and sCRI after CVC insertion. This underlines the importance of optimizing the conditions at the insertion and also of daily inspections, evaluation of future needs, and extra precautions to avoid sCRI in these susceptible patients.

Efficacy of an implementation package on documentation of central venous catheter insertions: an observational study

Background

Proper documentation of central venous catheter (CVC) insertions in electronic healthcare records is the basis for good follow-up and quality assurance. We have noted serious deficiencies in the documentation of CVC insertions and introduced an implementation package with the purpose of increasing the completeness of this documentation. The aim of the present study was to estimate the effect of the implementation package by assessing the proportion of missing data before and after the introduction of the implementation package.

Methods

In this single centre observational study, data from CVC insertion templates in a common electronic health record were extracted and analysed after introducing the implementation package. The package included adoption of new local CVC-directions, a new updated CVC-insertion template in the regional common electronic health record and a review of all CVC-insertion templates with a reminder to the inserting physician to supplement missing data. The proportion of terms with missing data was reviewed and also compared with the proportion of missing data in a study prior to the introduction of the package.

Results

In total, 7126 CVC-insertion templates were included. Of these 5539 (78%) were without missing data for any of the 13 predefined variables. Completed insertion templates for three common terms increased from 38% prior to the introduction of the implementation package to 93%, which represents an absolute reduction for missing data of 55% (95% CI 53% to 56%, p<0.0001).

Conclusion

The implementation package was highly effective in increasing the proportion of fully documented CVC insertions.

Comparative Study of the Antimicrobial Activity of Selenium Nanoparticles With Different Surface Chemistry and Structure

Although selenium nanoparticles (SeNPs) have gained attention in the scientific community mostly through investigation of their anticancer activity, a great potential of this nanomaterial was recognized recently regarding its antimicrobial activity. The particle form, size, and surface chemistry have been recognized as crucial parameters determining the interaction of nanomaterials with biological entities. Furthermore, considering a narrow boundary between beneficial and toxic effects for selenium per se, it is clear that investigations of biomedical applications of SeNPs are very demanding and must be done with great precautions. The goal of this work is to evaluate the effects of SeNPs surface chemistry and structure on antimicrobial activity against several common bacterial strains, including Staphylococcus aureus (ATCC 6538), Enterococcus faecalis (ATCC 29212), Bacillus subtilis (ATCC 6633), and Kocuria rhizophila (ATCC 9341), as well as Escherichia coli (ATCC 8739), Salmonella Abony (NCTC 6017), Klebsiella pneumoniae (NCIMB 9111) and Pseudomonas aeruginosa (ATCC 9027), and the standard yeast strain Candida albicans (ATCC 10231). Three types of SeNPs were synthesized by chemical reduction approach using different stabilizers and reducing agents: (i) bovine serum albumin (BSA) + ascorbic acid, (ii) chitosan + ascorbic acid, and (iii) with glucose. A thorough physicochemical characterization of the obtained SeNPs was performed to determine the effects of varying synthesis parameters on their morphology, size, structure, and surface chemistry. All SeNPs were amorphous, with spherical morphology and size in the range 70–300 nm. However, the SeNPs obtained under different synthesis conditions, i.e. by using different stabilizers as well as reducing agents, exhibited different antimicrobial activity as well as cytotoxicity which are crucial for their applications. In this paper, the antimicrobial screening of the selected systems is presented, which was determined by the broth microdilution method, and inhibitory influence on the production of monomicrobial and dual-species biofilm was evaluated. The potential mechanism of action of different systems is proposed. Additionally, the cytotoxicity of SeNPs was examined on the MRC-5 cell line, in the same concentration interval as for antimicrobial testing. It was shown that formulation SeNPs-BSA expressed a significantly lower cytotoxic effect than the other two formulations.