Systematic review of antimicrobial lock therapy for prevention of central-line-associated bloodstream infections in adult and pediatric cancer patients

Medical Device-Associated Biofilm Infections and Multidrug-Resistant Pathogens

Medical devices such as venous catheters (VCs) and urinary catheters (UCs) are widely used in the hospital setting. However, the implantation of these devices is often accompanied by complications. About 60 to 70% of nosocomial infections (NIs) are linked to biofilms. The main complication is the ability of microorganisms to adhere to surfaces and form biofilms which protect them and help them to persist in the host. Indeed, by crossing the skin barrier, the insertion of VC inevitably allows skin flora or accidental environmental contaminants to access the underlying tissues and cause fatal complications like bloodstream infections (BSIs). In fact, 80,000 central venous catheters-BSIs (CVC-BSIs)-mainly occur in intensive care units (ICUs) with a death rate of 12 to 25%. Similarly, catheter-associated urinary tract infections (CA-UTIs) are the most commonlyhospital-acquired infections (HAIs) worldwide.These infections represent up to 40% of NIs.In this review, we present a summary of biofilm formation steps. We provide an overview of two main and important infections in clinical settings linked to medical devices, namely the catheter-asociated bloodstream infections (CA-BSIs) and catheter-associated urinary tract infections (CA-UTIs), and highlight also the most multidrug resistant bacteria implicated in these infections. Furthermore, we draw attention toseveral useful prevention strategies, and advanced antimicrobial and antifouling approaches developed to reduce bacterial colonization on catheter surfaces and the incidence of the catheter-related infections.

Central Venous Catheter-related Bloodstream Infections Caused by Enterobacterales in Pediatric Oncology Patients: Catheter Salvage or Removal

BACKGROUND

The aim was to determine whether salvage treatment with systemic antibiotics is a safe and effective strategy for Enterobacterales bloodstream infections (BSI) in pediatric oncology patients with a central venous catheter (CVC).

METHODS

A retrospective study was performed on oncology and stem cell recipient patients with a CVC and blood culture with Enterobacterales , at the Princess Máxima Centre for Pediatric Oncology, Utrecht, the Netherlands. Analyses were performed for all BSI and for episodes meeting central line-associated bloodstream infection (CLABSI) criteria. The cumulative incidence of an event (ie, removal, intensive care admission or death) was estimated after blood culture collection for episodes primarily treated with antibiotics. The effect of prognostic factors on the hazard of the event of interest was assessed by estimating a Cox proportional hazard regression model.

RESULTS

In total, 95 CVC-related Enterobacterales BSIs in 82 patients were included; 12 (13%) BSIs required immediate CVC removal and for 83 (87%) BSIs CVC salvage was attempted. The cumulative incidence of events at 60 days was 53.0% [95% confidence interval (CI): 41.7-63.1] for BSIs (n = 83), and 64.4% (95% CI: 48.3-76.7) for CLABSIs (n = 45). The events occurred after a median of 6 (Q1-Q3: 2-15) and 6 (Q1-Q3: 2-20) days for BSIs and CLABSIs, respectively. Intensive care admission after salvage treatment was required in 16% of the BSIs and CLABSIs, resulting in death in 5% and 2% of cases, respectively. No significant association between risk factors and events was found.

CONCLUSIONS

The cumulative incidence of an event at 60 days after salvage treatment for Enterobacterales CLABSIs and BSIs in pediatric oncology patients is high. Immediate CVC removal appears recommendable for this patient group.

Epidemiologic and microbiologic evaluation of catheter-line bloodstream infection in a pediatric hematopoietic stem cell transplant center

BACKGROUND

Children who underwent hematopoietic stem cell transplant (HSCT) transplants are at high risk of developing central-line-associated bloodstream infections (CLABSIs). The present study aimed to identify possible risk factors for mortality by analyzing the clinical and laboratory characteristics of patients diagnosed with CLABSI in our pediatric hematopoietic stem cell transplant unit.

METHODS

The initial CLABSI episodes of 102 children were analyzed. Medical records of the patients were evaluated by preformed standardized surveys. Univariate analysis and multivariate logistic regression analysis were performed to identify risk factors for mortality.

RESULTS

Thirty-five patients (34.3%) were female. The median age was 48 months (3-204). The median time to onset of CLABSI was 19 days (4-150). The gram-negative and gram-positive bacteria ratio among the causative agents was 57.8% to 34.3%. The mortality rate was 12.6%. The presence of severe neutropenia, initiation of inappropriate empirical antibiotic therapy, the presence of hypotension, persistent bacteremia, pediatric intensive care unit admission, growth of carbapenemase-positive gram-negative microorganism and multidrug-resistant bacteria were significantly high in the mortality group when compared to survivors. The presence of hypotension, inappropriate empirical antibiotic therapy, and persistent bacteremia were found to be independent risk factors for mortality.

CONCLUSIONS

Rational use of antibiotics, active surveillance and screening of patients together with improved infection control practices may reduce the incidence and the consequences of CLABSIs.

Integration of Riboflavin-Modified Carbon Fiber Mesh Electrode Systems in a 3D-Printed Catheter Hub

BACKGROUND

Catheter line infection is a common complication within clinical environments, and there is a pressing need for technological options to aid in reducing the possibility of sepsis. The early identification of contamination could be pivotal in reducing cases and improving outcomes.

METHOD

A sensing rationale based on a riboflavin-modified electrode system integrated within a modified 3D-printed catheter needle-free connector is proposed, which can monitor changes in pH brought about by bacterial contamination.

RESULTS

Riboflavin, vitamin B2, is a biocompatible chemical that possesses a redox-active flavin core that is pH dependent. The oxidation peak potential of the adsorbed riboflavin responds linearly to changes in pH with a near-Nernstian behavior of 63 mV/pH unit and is capable of accurately monitoring the pH of an authentic IV infusate.

CONCLUSIONS

The proof of principle is demonstrated with an electrode-printed hub design offering a valuable foundation from which to explore bacterial interactions within the catheter lumen with the potential of providing an early warning of contamination.

Central-line-associated bloodstream infections and central-line-associated non-CLABSI complications among pediatric oncology patients

OBJECTIVE

To assess central venous catheter (CVC) harm in pediatric oncology patients, we explored risks for central-line-associated bloodstream infections (CLABSIs) and central-line-associated non-CLABSI complications (CLANCs).

DESIGN

Retrospective cohort study.

SETTING

Midwestern US pediatric oncology program.

PATIENTS

The study cohort comprised 592 pediatric oncology patients seen between 2006 and 2016.

METHODS

CLABSIs were defined according to Centers for Disease Control and Prevention (CDC)/National Health Safety Network (NHSN) definitions. CLANCs were classified using a novel definition requiring CVC removal. Patient-level and central-line-level risks were calculated using a negative binomial model to adjust for correlations between total events and line numbers.

RESULTS

CVCs were inserted in 62% of patients, with 175,937 total catheter days. The inpatient CLABSI and CLANC rates were 5.8 and 8.5 times higher than outpatient rates. At the patient level, shared risks included acute myeloid leukemia (AML) and age <1 year at diagnosis. At the line level, shared risks included age <1 year at diagnosis, non-mediports, and >1 lumen. AML was a CLABSI-specific risk. CLANC-specific risks included non-brain-tumor diagnosis, younger age at diagnosis or central-line placement, and age <1 year at diagnosis or line placement. Multivariable risks were for CLABSI >1 lumen and for CLANC age <1 year at placement.

CONCLUSIONS

Among patients with CVCs, CLABSI and CLANC rates were similar, higher among inpatients than outpatients. For both CLABSIs and CLANCs, infants and patients with AML were at higher risk. In both univariate and multivariate models, lines with >1 lumen were associated with CLABSIs and placement during infancy with CLANCs.

Safety and outcome of ultrasound-guided tunneled central venous catheter in children with cancers from low middle-income country: A prospective study

BACKGROUND

Central venous access devices (CVAD) are vital for cancer therapeutics in pediatric oncology. Tunneled vascular access devices (TVAD) are preferred in children for prolonged and frequent vascular access. Data on insertion, care, and complications of CVAD in children from low middle-income countries (LMIC) are scarce, heterogeneous, and retrospective.

PROCEDURE

This prospective observational study on eligible children <12 years with pediatric malignancies requiring chemotherapy for minimum 6 months from diagnosis excluded children with mucosal bleeding, coagulopathy, and infections. TVAD insertion was ultrasound (USG) guided. Number of catheter-days, surgical and nonsurgical complications, and risk factors for catheter-related bloodstream infections (CRBSI) were noted TVAD removal due to complications, therapy completion, tumor progression, or death.

RESULTS

Data from 61 of 86 eligible children with median age 42 months (range 1-144) were analyzed. Hematological malignancy and severe thrombocytopenia were seen in 37/61 (61%) and 18/61 (30%) children, respectively. First-attempt success rate was 74%. Surgical complications were seen in four of 61 (7%). Nonsurgical complications were seen in 33/61 (54%) children; CRBSI was commonest 24/61 (39%), causing removal of TVAD in 14/61 (23%). Incidence per 1000 catheter-days for CRBSI was 3.24. Antibiotic lock therapy could salvage nine of 24 TVAD with CRBSI. Thrombus and accidental removal was seen in six of 61 (10%) and four of 61 (7%). None of the studied risk factors were significantly associated with CRBSI. The mean insertion duration of TVAD was 121 ± 90 days.

CONCLUSION

USG-guided TVAD insertion is safe and reliable way for chemotherapy administration with acceptable complications in children with malignancies in LMIC, including children with severe thrombocytopenia.

Pre-Emptive Antimicrobial Locks Decrease Long-Term Catheter-Related Bloodstream Infections in Hemodialysis Patients

This study aimed to prove that pre-emptive antimicrobial locks in patients at risk of bacteremia decrease infection. We performed a non-randomized prospective pilot study of hemodialysis patients with tunneled central venous catheters. We drew quantitative blood cultures monthly to detect colonization. Patients with a critical catheter colonization by coagulase-negative staphylococci (defined as counts of 100−999 CFU/mL) were at high risk of developing a catheter-related bloodstream infection. We recommended antimicrobial lock for this set of patients. The nephrologist in charge of the patient decided whether to follow the recommendation or not (i.e., standard of care). We compared bloodstream infection rates between patients treated with antimicrobial lock therapy versus patients treated with the standard of care (i.e., heparin). We enrolled 149 patients and diagnosed 86 episodes of critical catheter colonization by coagulase-negative staphylococci. Patients treated with antimicrobial lock had a relative risk of bloodstream infection of 0.19 when compared with heparin lock (CI 95%, 0.11−0.33, p < 0.001) within three months of treatment. We avoided one catheter-related bloodstream infection for every ten catheter-critical colonizations treated with antimicrobial lock [number needed to treat 10, 95% CI, 5.26−100, p = 0.046]. In conclusion, pre-emptive antimicrobial locks decrease bloodstream infection rates in hemodialysis patients with critical catheter colonization.

Environmental, Microbiological, and Immunological Features of Bacterial Biofilms Associated with Implanted Medical Devices

The spread of biofilms on medical implants represents one of the principal triggers of persistent and chronic infections in clinical settings, and it has been the subject of many studies in the past few years, with most of them focused on prosthetic joint infections. We review here recent works on biofilm formation and microbial colonization on a large variety of indwelling devices, ranging from heart valves and pacemakers to urological and breast implants and from biliary stents and endoscopic tubes to contact lenses and neurosurgical implants. We focus on bacterial abundance and distribution across different devices and body sites and on the role of environmental features, such as the presence of fluid flow and properties of the implant surface, as well as on the interplay between bacterial colonization and the response of the human immune system.

Catheter salvage strategies in children with central venous catheter related or associated bloodstream infections: a systematic review and meta-analysis

BACKGROUND

Optimal management of Central Venous Catheter related, or associated, bloodstream infections (CRBSI or CLABSI) in children is not established.

OBJECTIVE

To evaluate successful of catheter salvage strategies in pediatric patients.

METHODS

Studies retrieved from medical databases and article reference lists. Data were collected relating to clinical outcomes of 2 treatments: systemic antibiotics alone or in association with antimicrobial lock therapy (ALT). 95% CIs and OR were calculated from a mixed logistic effects model. Heterogeneity was summarized using I2 statistics. Publication bias was investigated by Egger's regression test and funnel plots.

RESULTS

From 345 identified publications, 19 met inclusion criteria (total of 914 attempted salvage strategies. To achieve successful catheter salvage, in CRBSI the addition of ALT was superior to systemic antibiotics alone (OR -0.40, 95%CI -1.41 - 0.62): 77% (95%CI 69-85, I2=42.5%, p=0.12) and 68% of success (95%CI 59-77, I2=0, p<0.05), respectively. CRBSI recurrence was less common in studies that used ALT compared with systemic antibiotics alone: 5% (95%CI 0-13, I2=59.7%; p=0.03) and 18% of recurrence (95%CI, 9-28, I2=0, p< 0.05), respectively. Recurrences were low with both antibiotic-locks and ethanol-lock. No clear benefits of ALT addition compared to systemic antibiotic only was found in CLABSI (OR -0.81, 95% CI -0.80 - 2.43).

CONCLUSIONS

The addition of an antimicrobial lock solution to systemic antibiotic may be beneficial for successful catheter salvage in pediatric patients with CRBSI, depending on etiology, whilst no statistically significant difference between systemic antibiotic with or without addition of an antimicrobial lock solution was found regarding CLABSI.

Antifungal lock therapy: an eternal promise or an effective alternative therapeutic approach?

Each year, millions of central venous catheter insertions are performed in intensive care units worldwide. The usage of these indwelling devices is associated with a high risk of bacterial and fungal colonization, leading to the development of microbial consortia, namely biofilms. These sessile structures provide fungal cells with resistance to the majority of antifungals, environmental stress and host immune responses. Based on different guidelines, colonized/infected catheters should be removed and changed immediately in the case of Candida‐related central line infections. However, catheter replacement is not feasible for all patient populations. An alternative therapeutic approach may be antifungal lock therapy, which has received high interest, especially in the last decade. This review summarizes the published Candida‐related in vitro, in vivo data and case studies in terms of antifungal lock therapy. The number of clinical studies remains limited and further studies are needed for safe implementation of the antifungal lock therapy into clinical practice.

The risk of fatal bleeding complications in jugular catheterization in patients with coagulopathy: A retrospective analysis of death cases in closed claims and the Medical Accident Investigating System in Japan

Background

To prevent recurrence of medical accidents, the Medical Accident Investigating System was implemented in October 2015 by the Japan Medical Safety Research Organization (Medsafe Japan) to target deaths from medical care that were unforeseen by the administrator. Medsafe Japan analyzed the 10 cases of central venous catheterization-related deaths reported in the system and published recommendations in March 2017. However, the particular emphasis for the prevention of central venous catheterization-related deaths is unclear.

Methods

This study aimed to identify the recommendation points that should be emphasized to prevent recurrence of central venous catheterization-related deaths. We assessed central venous catheterization in 8530 closed-claim cases between January 2002 and December 2016 covered by the medical insurer Sompo-Japan. Moreover, we compared central venous catheterization-related death in closed-claim cases with death in reported cases.

Results

The background, error type, anatomic insertion site, and fatal complication data were evaluated for 37 closed-claim cases, of which 12 (32.4%) were death cases. Of the 12 closed-claim cases and 10 reported cases, 9 (75.0%) closed-claim cases and 9 (90.0%) reported cases were related to vascular access. Among these, 5 closed-claim cases (41.7%) and 7 reported cases (77.8%) were related to internal jugular vein catheterization (p = 0.28). Coagulopathy was observed in 3 (60.0%) of 5 closed-claim cases and 6 (85.7%) of 7 reported cases.

Conclusions

The risk of internal jugular catheterization in patients with coagulopathy must be carefully considered.

Profilaxia com lock de etanol em cateter venoso central de longa permanência em crianças com disfunção intestinal grave: relato de seis casos

The aim of this study was to report on use of ethanol lock in long-term catheters in newborns with severe intestinal dysfunction, dependent on total and prolonged parenteral nutrition, in a Neonatal Intensive Care Center (tertiary level), between 2015 and 2020. Six infants (0.65%) out of the 914 admitted during the period met the inclusion criteria. The median age at catheter placement was 121.5 days. Two Powerpicc (PICC Power Sinergy™, São Paulo), one Groshong (Groshong™ Central Venous Catheter BD, São Paulo), and three silicone catheters were used, all tunneled, and the median dwell duration was 182.5 days. Four patients had at least one episode of infection related to the central venous catheter, and Gram-positive, Gram-negative, and fungal agents were isolated. The median length of hospital stay was 555 days and mortality was 33.3%. The ethanol lock did not cause any side effects and was relatively effective in preventing infections related to the central venous catheter.

Ethanol lock prophylaxis in long-stay central venous catheters in children with severe intestinal dysfunction: a report of six cases

Abstract The aim of this study was to report on use of ethanol lock in long-term catheters in newborns with severe intestinal dysfunction, dependent on total and prolonged parenteral nutrition, in a Neonatal Intensive Care Center (tertiary level), between 2015 and 2020. Six infants (0.65%) out of the 914 admitted during the period met the inclusion criteria. The median age at catheter placement was 121.5 days. Two Powerpicc (PICC Power Sinergy™, São Paulo), one Groshong (Groshong™ Central Venous Catheter BD, São Paulo), and three silicone catheters were used, all tunneled, and the median dwell duration was 182.5 days. Four patients had at least one episode of infection related to the central venous catheter, and Gram-positive, Gram-negative, and fungal agents were isolated. The median length of hospital stay was 555 days and mortality was 33.3%. The ethanol lock did not cause any side effects and was relatively effective in preventing infections related to the central venous catheter.

Self-targeting of zwitterion-based platforms for nano-antimicrobials and nano-carriers

Self-targeting antimicrobial platforms have yielded new possibilities for the treatment of infectious biofilms. Self-targeting involves stealth transport through the blood circulation towards an infectious biofilm, where the antimicrobial platform penetrates...

Risk Factors for Infections, Antibiotic Therapy, and Its Impact on Cancer Therapy Outcomes for Patients with Solid Tumors

Infections represent a significant cause of morbidity and mortality in cancer patients. Multiple factors related to the patient, tumor, and cancer therapy can affect the risk of infection in patients with solid tumors. A thorough understanding of such factors can aid in the identification of patients with substantial risk of infection, allowing medical practitioners to tailor therapy and apply prophylactic measures to avoid serious complications. The use of novel treatment modalities, including targeted therapy and immunotherapy, brings diagnostic and therapeutic challenges into the management of infections in cancer patients. A growing body of evidence suggests that antibiotic therapy can modulate both toxicity and antitumor response induced by chemotherapy, radiotherapy, and especially immunotherapy. This article provides a comprehensive review of potential risk factors for infections and therapeutic approaches for the most prevalent infections in patients with solid tumors, and discusses the potential effect of antibiotic therapy on toxicity and efficacy of cancer therapy.

The efficacy of taurolidine containing lock solutions for the prevention of central-venous-catheter-related bloodstream infections: a systematic review and meta-analysis

The incidence of central venous catheter (CVC)-related bloodstream infections is high in patients requiring a long-term CVC. Therefore, infection prevention is of the utmost importance. The aim of this study was to provide an updated overview of randomized controlled trials (RCTs) comparing the efficacy of taurolidine containing lock solutions (TL) to other lock solutions for the prevention of CVC-related bloodstream infections in all patient populations. On 15^th February 2021, PubMed, Embase and The Cochrane Library were searched for RCTs comparing the efficacy of TLs for the prevention of CVC-related bloodstream infections with other lock solutions. Exclusion criteria were non-RCTs, studies describing <10 patients and studies using TLs as treatment. Risk of bias was evaluated using the Cochrane Risk of Bias 2 tool. A random effects model was used to pool individual study incidence rate ratios (IRRs). Subgroup analyses were performed based on the following factors: CVC indication, comparator lock and bacterial isolates cultured. A total of 14 articles were included in the qualitative synthesis describing 1219 haemodialysis, total parenteral nutrition and oncology patients. The pooled IRR estimated for all patient groups together (nine studies; 918 patients) was 0.30 (95% confidence interval 0.19-0.46), favouring the TLs. Adverse events (10 studies; 867 patients) were mild and scarce. The quality of the evidence was limited due to a high risk of bias and indirectness of evidence. The use of TLs might be promising for the prevention of CVC-related bloodstream infections. Large-scale RCTs are needed to draw firm conclusions on the efficacy of TLs.

Prophylactic antibiotics for preventing gram-positive infections associated with long-term central venous catheters in adults and children receiving treatment for cancer

BACKGROUND

This is an updated version of a Cochrane Review last published in 2013. Long-term central venous catheters (CVCs), including tunnelled CVCs (TCVCs) and totally implanted devices or ports (TIDs), are increasingly used when treating people with cancer. Despite international guidelines on sterile insertion and appropriate CVC maintenance and use, infections remain a common complication. These infections are mainly caused by gram-positive bacteria. Antimicrobial prevention strategies aimed at these micro-organisms could potentially decrease the majority of CVC-related infections. The aim of this review was to evaluate the efficacy of prophylactic antibiotics for the prevention of gram-positive infections in people with cancer who have long-term CVCs.

OBJECTIVES

To assess the effects of administering antibiotics prior to the insertion of long-term CVCs or as a flush/lock solution, or both during long-term CVC access to prevent gram-positive CVC-related infections in adults and children receiving treatment for cancer.

SEARCH METHODS

The search for this updated review was conducted on 19 November 2020. We searched the Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library, MEDLINE via Ovid and Embase via Ovid. We searched ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform portal for additional articles.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared either the administration of prophylactic antibiotics prior to long-term CVC insertion versus no administration of antibiotics, or the use of an antibiotic versus a non-antibiotic flush/lock solution in long-term CVCs, in adults and children receiving treatment for cancer.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Two authors independently selected studies, classified them and extracted data onto a predesigned data collection form. The outcomes of interest were gram-positive catheter-related infection events and total number of CVCs and CVC days. We pooled the data using a random-effects model for meta-analyses. We used the GRADE approach to assess the certainty of the evidence.  MAIN RESULTS: For this update, we identified 310 potentially relevant studies and screened them for eligibility. We included one additional RCT with 404 participants. The original review included 11 RCTs with a total of 840 people with cancer (adults and children). In total this review included 12 RCTs with 1244 participants. Antibiotics prior to insertion of the CVC Six trials compared the use of antibiotics (vancomycin, teicoplanin, ceftazidime or cefazolin) versus no antibiotics given before the insertion of a long-term CVC. One study did not observe any CVC-related infection events in either group was not included in the quantitative analysis as it was not possible to calculate a risk ratio. Administering an antibiotic prior to insertion of the CVC may not reduce gram-positive CVC-related infections (pooled risk ratio 0.67, confidence interval (CI) 95% 0.32 to 1.43; control versus intervention group risk 10.4% versus 7.3% of the participants; 5 studies, 648 participants; moderate-certainty evidence). We sought adverse event data, but these were not described by the authors. The overall risk of bias was deemed low.   Antibiotics as a flushing or locking solution Six trials compared a combined antibiotic (vancomycin, amikacin or taurolidine) and heparin solution with a heparin-only solution for flushing or locking the long-term CVC after use. One study did not observe any CRS events and was not include this study in the quantitative analysis as it was not possible to calculate a risk ratio. Flushing and locking long-term CVCs with a combined antibiotic and heparin solution likely reduced the risk of gram-positive CVC-related infections compared to a heparin-only solution (pooled rate ratio 0.47, CI 95% 0.26 to 0.85; control versus intervention group rate ratio 0.66 versus 0.27 per 1000 CVC-days; 5 studies, 443 participants; moderate-certainty evidence). One trial reported a higher incidence of occlusions and participants in one trial reported an unpleasant taste after flushing associated with a combined antibiotic and heparin solution. The overall risk of bias was deemed low.  AUTHORS' CONCLUSIONS: Since the last version of this review, we included one additional study. There was no observed benefit of administering antibiotics before the insertion of long-term CVCs to prevent gram-positive CVC-related infections. Flushing or locking long-term CVCs with an antibiotic solution likely reduces gram-positive CVC-related infections experienced in people at risk of neutropenia through chemotherapy or disease. However, a limitation of this review is heterogeneity between the studies for both outcomes. Insufficient data were available to evaluate if the conclusions apply equally for different CVC types and for adults versus children. It must be noted that the use of an antibiotic flush/lock solution may increase microbial antibiotic resistance, therefore it should be reserved for high-risk people or if the baseline CVC-related infection rates are high. Further research is needed to identify high-risk groups most likely to benefit from these antibiotic flush/lock solutions.

Equal effect of vancomycin lock with or without heparin in treatment of central venous catheter related blood stream infections - an observational study in palliative home care

BACKGROUND

Catheter related blood stream infections is a complication in patients with central venous catheter. The aim of this study was to compare vancomycin-heparin-lock and non-heparin, high-dose vancomycin-lock as treatment in patients admitted to palliative home care. With non-heparin, high-dose vancomycin-lock a high concentration of 5 mg/mL vancomycin is attained instead of only 500 ug/mL when dissolved in heparin. The non-heparin method also has the advantage of being easier and cheaper but might entail an increased risk of clotting.

METHODS

Medical records from patients enrolled at a palliative home care unit in Stockholm between 2016 and 2018 were reviewed retrospectively. Three divisions used vancomycin-heparin-lock and the other 3 divisions used non-heparin, high-dose vancomycin-lock. Inclusion criteria were a central venous catheter related blood stream infection treated with one of the two methods for >7 days and a follow-up blood culture at the end of treatment.

RESULTS

Twenty-five patients fulfilled the inclusion criteria, 12 treated with vancomycin-heparin-lock and 13 with non-heparin, high-dose vancomycin-lock. There was no significant difference in resolved infections between the two treatments, 6 of 12 for vancomycin-heparin-lock and 10 of 13 for non-heparin, high-dose vancomycin-lock (p = .23). In the non-heparin group one central venous catheter was removed due to clotting although the infection had resolved. Overall, removal of central venous catheter was similar in the two groups (6 of 12 and 4 of 13, p = .43).

CONCLUSION

The current study does not support superiority of one treatment over the other. However, larger, randomized studies are needed, before firm conclusions can be drawn.

Mechanistic Understanding of Candida albicans Biofilm Formation and Approaches for Its Inhibition

In recent years, the demand for novel antifungal therapies has increased several- folds due to its potential to treat severe biofilm-associated infections. Biofilms are made by the sessile microorganisms attached to the abiotic or biotic surfaces, enclosed in a matrix of exopolymeric substances. This results in new phenotypic characteristics and intrinsic resistance from both host immune response and antimicrobial drugs. Candida albicans biofilm is a complex association of hyphal cells that are associated with both abiotic and animal tissues. It is an invasive fungal infection and acts as an important virulent factor. The challenges linked with biofilm-associated diseases have urged scientists to uncover the factors responsible for the formation and maturation of biofilm. Several strategies have been developed that could be adopted to eradicate biofilm-associated infections. This article presents an overview of the role of C. albicans biofilm in its pathogenicity, challenges it poses and threats associated with its formation. Further, it discusses strategies that are currently available or under development targeting prostaglandins, quorum-sensing, changing surface properties of biomedical devices, natural scaffolds, and small molecule-based chemical approaches to combat the threat of C. albicans biofilm. This review also highlights the recent developments in finding ways to increase the penetration of drugs into the extracellular matrix of biofilm using different nanomaterials against C. albicans.

Central venous catheter-related infections in hematology and oncology: 2020 updated guidelines on diagnosis, management, and prevention by the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Medical Oncology (DGHO)

Cancer patients frequently require central venous catheters for therapy and parenteral nutrition and are at high risk of central venous catheter-related infections (CRIs). Moreover, CRIs prolong hospitalization, cause an excess in resource utilization and treatment cost, often delay anti-cancer treatment, and are associated with a significant increase in mortality in cancer patients. We therefore summoned a panel of experts by the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Medical Oncology (DGHO) and updated our previous guideline on CRIs in cancer patients. After conducting systematic literature searches on PubMed, Medline, and Cochrane databases, video- and meeting-based consensus discussions were held. In the presented guideline, we summarize recommendations on definition, diagnosis, management, and prevention of CRIs in cancer patients including the grading of strength of recommendations and the respective levels of evidence. This guideline supports clinicians and researchers alike in the evidence-based decision-making in the management of CRIs in cancer patients.

A Glance at Antimicrobial Strategies to Prevent Catheter-Associated Medical Infections

Urinary and intravascular catheters are two of the most used invasive medical devices; however, microbial colonization of catheter surfaces is responsible for most healthcare-associated infections (HAIs). Several antimicrobial-coated catheters are available, but recurrent antibiotic therapy can decrease their potential activity against resistant bacterial strains. The aim of this Review is to question the actual effectiveness of currently used (coated) catheters and describe the progress and promise of alternative antimicrobial coatings. Different strategies have been reviewed with the common goal of preventing biofilm formation on catheters, including release-based approaches using antibiotics, antiseptics, nitric oxide, 5-fluorouracil, and silver as well as contact-killing approaches employing quaternary ammonium compounds, chitosan, antimicrobial peptides, and enzymes. All of these strategies have given proof of antimicrobial efficacy by modifying the physiology of pathogens or disrupting their structural integrity. The aim for synergistic approaches using multitarget processes and the combination of both antifouling and bactericidal properties holds potential for the near future. Despite intensive research in biofilm preventive strategies, laboratorial studies still present some limitations since experimental conditions usually are not the same and also differ from biological conditions encountered when the catheter is inserted in the human body. Consequently, in most cases, the efficacy data obtained from in vitro studies is not properly reflected in the clinical setting. Thus, further well-designed clinical trials and additional cytotoxicity studies are needed to prove the efficacy and safety of the developed antimicrobial strategies in the prevention of biofilm formation at catheter surfaces.

Dwindling Utilization of Central Venous Catheter Tip Cultures: An Analysis of Sampling Trends and Clinical Utility at 128 US Hospitals, 2009-2014

At 128 US hospitals, from 2009-2014, a 17% decline occurred annually in central venous catheter tips sent for culture: a 6-fold decrease from blood culture sampling trends. The positive predictive value was low (23%). Tip culture use often does not conform to recommendations and offers limited independent treatment opportunities.

Minimising Blood Stream Infection: Developing New Materials for Intravascular Catheters

Catheter related blood stream infection is an ever present hazard for those patients requiring venous access and particularly for those requiring long term medication. The implementation of more rigorous care bundles and greater adherence to aseptic techniques have yielded substantial reductions in infection rates but the latter is still far from acceptable and continues to place a heavy burden on patients and healthcare providers. While advances in engineering design and the arrival of functional materials hold considerable promise for the development of a new generation of catheters, many challenges remain. The aim of this review is to identify the issues that presently impact catheter performance and provide a critical evaluation of the design considerations that are emerging in the pursuit of these new catheter systems.

Amiodarone that has antibacterial effect against human pathogens may represent a novel catheter lock

Infection is one of the most feared hospital-acquired complications. Infusion therapy is frequently administered through a central line. Infusions facilitating bacterial growth may be a source of central line-associated bloodstream infections. On the other hand, medications that kill bacteria may protect against this kind of infection and may be used as a catheter lock.In this study, we examined the impact of amiodarone on bacterial growth. Amiodarone is used for controlling cardiac arrhythmias and can be administered as an infusion for weeks. Standard microbiological methods have been used to study the growth of laboratory strains and clinical isolates of Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, and multidrug-resistant Acinetobacter baumannii in amiodarone. The minimum inhibitory concentration (MIC) of amiodarone was determined. Bacterial growth from in use amiodarone syringes and giving sets was also investigated.Most examined strains were killed within 1 min in amiodarone. The other strains were killed within 1 h. The MICs of amiodarone were <0.5-32 μg/mL.Amiodarone infusion is unlikely to be responsible for bloodstream infections as contaminating bacteria are killed within 1 h. Amiodarone may also protect against central line infections if used as a catheter lock.

Central venous catheter insertion and maintenance: Evidence-based clinical recommendations

OBJECTIVE

To share with clinicians supporting evidence of the safest and the most effective processes for central venous catheter insertion and maintenance as a strategy to prevent catheter-associated bloodstream infections.

METHODS

A literature search was conducted in the Medline via PubMed, Embase Central and Lilacs databases based on a set of clinical questions aimed at improving safety and effectiveness at key moments in the process of central venous catheter insertion and maintenance. The rapid literature review methodology was used. The studies identified were assessed from the quality point of view, using the Joanna Briggs Institute (JBI) tools for qualitative and quantitative studies and for systematic reviews. Clinical practice guidelines were assessed using the AGREE II tool. The evidence is presented in the form of evidence-based clinical recommendations, which were graded in accordance with the JBI methodology.

RESULTS

Twelve clinical evidence summaries containing evidence related to the safe and effective use of central venous catheters are presented, including the following topics: central venous catheter insertion (CVC), peripherally inserted central catheters (PICC), preoperative assessment, the use of analgesia, field preparation, choice between CVC or PICC, CVC care and maintenance, prevention of complications, and general considerations pertaining to the use of central venous catheters in oncologic patients and in parenteral nutrition.

CONCLUSIONS

Recommendations on the safe and effective use of central venous access catheters in relation to CVC insertion and maintenance processes are presented in the evidence-based summary model. It is necessary to evaluate their implementation in health outcomes in the institutions where they are developed.

Long-term vascular access in differently resourced settings: a review of indications, devices, techniques, and complications

Central venous access is frequently essential for the management of many acute and chronic conditions in children. Millions of central venous access devices (CVADs) are placed each year. In this review article, we discuss the indications for long-term vascular access, the types of devices available, the state of the art of central venous cannulation and device placement, and the complications of long-term central venous access. We pay a special attention to the challenges of, and options for long-term central venous access, also those in developing countries, with limited financial, human, and material resources.

Taurolidine lock solution for catheter-related bloodstream infections in pediatric patients: A meta-analysis

Infection is one of the most commonly described complications, and a major cause of morbidity and mortality in pediatric patients treated using central venous catheters (CVCs). Taurolidine lock solutions have been used to decrease catheter-related bloodstream infections (CRBSIs) in both adult and pediatric patients. The purpose of this study was to systematically search the literature and conduct a meta-analysis to determine the efficacy of taurolidine in reducing CRBSI in children. We conducted an electronic search of the PubMed, EMBASE, Cochrane Library, TRIP Database, CINAHL, and Google Scholar databases for articles published up to 1^st November 2019. Eligible studies included randomized controlled trials (RCTs) comparing the effects of taurolidine with control for preventing CRBSI in pediatric patients. Four studies were included. Our results indicated a statistical significant reduction in the total number of CRBSI with taurolidine as compared to control (RR: 0.23; 95% CI:0.13, 0.40; I² = 0%; P<0.00001). The pooled analysis also indicated a statistical significant reduction in the incidence of CRBSI (defined as the number of CRBSI events/1000 catheter days) in the taurolidine group (MD: -1.12; 95% CI:-1.54, -0.71; I² = 1%; P<0.00001). The number of catheters removed due to infection or suspected infection was not significantly different between the two groups (RR: 0.68; 95% CI:0.22, 2.10; I² = 56%; P = 0.50) (Fig 5). The quality of the included studies was not high. The use of taurolidine as a catheter locking solution may significantly reduce CRBSI in pediatric patients. However, the quality of current evidence is not high and further high-quality large scale RCTs are needed to corroborate our results.

Antimicrobial Lock Therapy in Clinical Practice: A Scoping Review Protocol

Our objective is to review the scientific literature on the use of antimicrobial lock therapy (ALT). To achieve this result, our scoping review will address the following seven key questions: 1) Who are the patients who will benefit from this technique? 2) What are the techniques utilized? 3) What are the settings in which the technique is performed? 4) When the technique is performed? 5) Why the technique is performed? 6) How the technique is performed? 7) In how much amount, of such technique performed? This review considers all studies published in full and in peer-reviewed journals, with no restrictions on language, on the year of publication and age of the participants. Both randomized controlled trials and observational studies will be included. This scoping review has been planned on a five-stage framework: 1. Identifying the review question; 2. identifying relevant studies; 3. study selection; 4. charting the data; 5. collating, summarizing, and reporting the results. It is conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Guidelines. The databases utilized will include MEDLINE via PubMed, EMBASE and Cochrane Central Register of Controlled Trials and Grey Literature. SCOPING REVIEW REGISTRATION: Open Science Framework https://osf.io/vphwm/.

A Randomized, Double-Blind, Placebo-Controlled Trial (TAURCAT Study) of Citrate Lock Solution for Prevention of Endoluminal Central Venous Catheter Infection in Neutropenic Hematological Patients

Infection of long-term central venous catheters (CVCs) remains a challenge in the clinical management of cancer patients. We aimed to determine whether a lock solution with taurolidine-citrate-heparin would be more effective than placebo for preventing nontunneled CVC infection in high-risk neutropenic hematologic patients. We performed a prospective, multicenter, randomized (1:1), double-blind, parallel, superiority, placebo-controlled trial involving 150 hematological patients with neutropenia carrying nontunneled CVCs who were assigned to receive CVC lock solution with taurolidine-citrate-heparin or heparin alone. The primary endpoint was bacterial colonization of the CVC hubs. Secondary endpoints were the incidence of catheter-related bloodstream infection (CRBSI), CVC removal, adverse events related to the lock solution, and the 30-day case fatality rate. CVC lock solution with taurolidine-citrate-heparin was associated with less colonization of the CVC hubs than that with placebo, with no statistically significant differences: 4.1%, versus 10.1% (relative risk [RR] = 0.41, 95% confidence interval [CI] = 0.11 to 1.52), with a cumulative incidence of 4.17 (95% CI = 0.87 to 11.70) and 10.14 (95% CI = 4.18 to 19.79), respectively. There were no significant differences regarding the secondary endpoints. Only three episodes of CRBSI occurred during the study period. No adverse events related to the administration of the lock solution occurred. In this trial involving high-risk patients carrying nontunneled CVCs, the use of taurolidine-citrate-heparin did not show a benefit over the use of placebo. Nevertheless, the safety of this prevention strategy and the trend toward less hub colonization in the taurolidine-citrate-heparin group raise the interest in assessing its efficacy in centers with higher rates of CRBSI. (This study has been registered in ISRCTN under identifier ISRCTN47102251.).

Taurolidine-citrate lock solution for the prevention of central line-associated bloodstream infection in paediatric haematology-oncology and gastrointestinal failure patients with high baseline central-line associated bloodstream infection rates

AIM

Central line-associated bloodstream infection associated bloodstream infection (CLABSI) is a serious complication of patients on central venous catheters (CVC). Taurolidine-citrate solution (TCS) is a catheter-lock solution with broad-spectrum antimicrobial action. This study's aim was to evaluate the efficacy of TCS in reducing CLABSI rates in paediatric haematology-oncology (H/O) and gastrointestinal (GI) patients with long-term CVC.

METHODS

This was an open-label trial of H/O and GI inpatients with the following inclusion criteria: <17 years old, more than or equal to one previous CLABSI and a minimum TCS dwell time of ≥8 h. CLABSI per 1000 catheter-days was calculated from each patient's first CVC insertion till 14 December 2017 or until TCS discontinuation.

RESULTS

Thirty-three patients were recruited with a median age of 3.5 years; H/O and GI constituted 60.6 and 39.4% respectively. CVC types were Hickman line (45.5%), implantable port (24.2%) and peripherally inserted central catheter (30.3%). Mean pre- and post-TCS CLABSI rates per 1000 catheter-days were 14.44 and 2.45 (P < 0.001) for all patients; 16.55 and 2.81 for H/O patients; and 11.21 and 1.90 for GI patients, respectively. Pre- and post-TCS rate ratio was 0.20, 0.10 and 0.30 for all, H/O and GI patients, respectively (P < 0.001). TCS also led to a reduction in CVC removal from 66.7 to 9.09% (P < 0.001).

CONCLUSIONS

TCS usage was highly successful in CLABSI reduction by 80% in all patients, 90% in H/O and 70% in GI patients. In patients with high baseline CLABSI rates, TCS is an effective catheter-lock therapy to reduce CLABSI rates in paediatric patients.

What is the best catheter lock solution in preventing catheter-related blood infections? A protocol for a Bayesian network meta-analysis of randomised controlled trials

INTRODUCTION

Catheter-related bloodstream infection (CRBSI) is a major complication after central venous catheter insertion, which is associated with significant morbidity, mortality and additional medical costs. Many lock solutions for CRBSI have been evaluated. However, using traditional pairwise meta-analyses to summarise the evidence does not allow the inclusion of data from treatments that have not been compared head to head, which could impact the precision of pooled estimates in a meta-analysis. Therefore, we evaluated the efficacy and safety of the different lock solutions for CRBSI through a network meta-analysis.

METHODS AND ANALYSIS

The primary outcome of this network meta-analysis is the CRBSI. The secondary outcomes are exit-site infection and catheter-related thrombosis. We will search the PubMed, Embase, Web of Science and the Cochrane Library databases for recent relevant meta-analysis and their reference lists to include randomised controlled trials (RCTs) that compared lock solutions for CRBSI prevention. Two individuals will independently extract data from each included RCT according to a predesigned Excel spreadsheet and will assess the methodological quality using the Cochrane risk of bias tool. We will analyse the data using WinBUGS (V.1.4.3) and Stata (V.15.0). We will also estimate the pooled direct and indirect effects for all lock solutions using the network meta-analysis.

ETHICS AND DISSEMINATION

As the present meta-analysis is performed based on previous published studies, no ethical approval and patient safety considerations are required. This study commenced on 18 January 2019, and its expected completion date is 1 December 2019. We will disseminate the results of our network meta-analysis through an international peer-reviewed journal.

PROSPERO REGISTRATION NUMBER

CRD42019121089.

A new class of prophylactic metallo-antibiotic possessing potent anti-cancer and anti-microbial properties

A family of metallo-antibiotics of general formula [Cu(N,N)(CipA)Cl] where N,N is a phenanthrene ligand and CipA is a derivative of the clinically used fluoroquinolone antibiotic ciprofloxacin – targeting immunocompromised cancer patients undergoing chemotherapy.

Efficacy of β-phenylethylamine as a novel anti-microbial and application as a liquid catheter flush

With this study, we introduce a liquid flush for catheters and other tubing-based applications that consists of a solution of β-phenylethylamine (PEA) in tryptic soy broth. The initial experiments in multiwell polystyrene plates were conducted with Escherichia coli K-12 to assess the effectiveness of PEA at reducing planktonic growth, as well as the biomass and adenosine triphosphate (ATP) content of biofilm; PEA reduced these growth parameters as a function of increasing concentration. This effect was also seen in mutants of PEA catabolism, which leads us to believe that the PEA effect is due to PEA itself and not one of its degradation products. Since PEA reduced planktonic growth and biofilm when added at the time of inoculation, as well as at later time points, we propose PEA as a novel compound for the prevention and treatment of biofilm. PEA reduced planktonic growth and the ATP content of the biofilm for five bacterial pathogens, including an enterohemorrhagic E. coli, two uropathogenic E. coli, Pseudomonas aeruginosa and Staphylococcus aureus. A major finding of this study is the reduction of the ATP content of biofilm that formed in silicone tubing by periodic flushes of PEA. This experiment was performed to model antibiotic-lock treatment of an intravenous catheter. It was found that 10 mg ml^-1 of PEA reduced the ATP content of biofilm of five bacterial strains by 96.3 % or more after 2 weeks of incubation and three treatments with PEA. For P. aeruginosa, the reduction in ATP content was paralleled by an identical percentage reduction in viable cells in the biofilm.

In Vitro and In Vivo Activity of a Novel Catheter Lock Solution against Bacterial and Fungal Biofilms

Central-line-associated bloodstream infections are increasingly recognized to be associated with intraluminal microbial biofilms, and effective measures for the prevention and treatment of bloodstream infections remain lacking. This report evaluates a new commercially developed antimicrobial catheter lock solution (ACL), containing trimethoprim (5 mg/ml), ethanol (25%), and calcium EDTA (Ca-EDTA) (3%), for activity against bacterial and fungal biofilms, using in vitro and in vivo (rabbit) catheter biofilm models. Biofilms were formed by bacterial (seven different species, including vancomycin-resistant Enterococcus [VRE]) or fungal (Candida albicans) species on catheter materials. Biofilm formation was evaluated by quantitative culture (CFU) and scanning electron microscopy (SEM). Treatment with ACL inhibited the growth of adhesion-phase biofilms in vitro after 60 min (VRE) or 15 min (all others), while mature biofilms were completely inhibited after exposure for 2 or 4 h, compared to control. Similar results were observed for drug-resistant bacteria. Compared to the heparinized saline controls, ACL lock therapy significantly reduced the catheter bacterial (3.49 ± 0.75 versus 0.03 ± 0.06 log CFU/catheter; P = 0.016) and fungal (2.48 ± 1.60 versus 0.55 ± 1.19 log CFU/catheter segment; P = 0.013) burdens in the catheterized rabbit model. SEM also demonstrated eradication of bacterial and fungal biofilms in vivo on catheters exposed to ACL, while vigorous biofilms were observed on untreated control catheters. Our results demonstrated that ACL was efficacious against both adhesion-phase and mature biofilms formed by bacteria and fungi in vitro and in vivo.

Treatment and secondary prophylaxis with ethanol lock therapy for central line-associated bloodstream infection in paediatric cancer: a randomised, double-blind, controlled trial

BACKGROUND

Central line-associated bloodstream infections (CLABSIs) affect about 25% of children with cancer, and treatment failure is common. Adjunctive ethanol lock therapy might prevent treatment failure but high-quality evidence is scarce. We evaluated ethanol lock therapy as treatment and secondary prophylaxis for CLABSI in children with cancer or haematological disorders.

METHODS

This randomised, double-blind, placebo-controlled superiority trial, with two interim futility and efficacy analyses (done when the first 46 and 92 evaluable participants completed study requirements), was done at two paediatric hospitals in the USA and Australia. Patients aged 6 months to 24 years, inclusive, with cancer or a haematological disorder and new CLABSI were eligible. Participants were randomly assigned (1:1) to receive either ethanol lock therapy (70% ethanol) or placebo (heparinised saline) for 2-4 h per lumen daily for 5 days (treatment phase), then for up to 3 non-consecutive days per week for 24 weeks (prophylaxis phase). The primary composite outcome was treatment failure, consisting of attributable catheter removal or death, new or persistent (>72 h) infection, or additional lock therapy during the treatment phase, and recurrent CLABSI during the prophylaxis phase. This trial is registered with ClinicalTrials.gov, number NCT01472965.

FINDINGS

94 evaluable participants were enrolled between Dec 14, 2011, and Sept 12, 2016, of whom 48 received ethanol lock therapy and 46 received placebo. The study met futility criteria at the second interim analysis. Treatment failure was similar with ethanol lock therapy (21 [44%] of 48) and placebo (20 [43%] of 46; relative risk [RR] 1·0, 95% CI 0·6-1·6; p=0·98). Some adverse events, including infusion reactions and catheter occlusion, were more frequent in the ethanol lock therapy group than in the placebo group. Catheter occlusion requiring thrombolytic therapy was more common with ethanol lock therapy (28 [58%] of 48) than with placebo (15 [33%] of 46; RR 1·8, 95% CI 1·1-2·9; p=0·012). Discontinuation of lock therapy because of adverse effects or patient request occurred in a similar proportion of participants in the ethanol lock therapy (nine [19%] of 48) and placebo groups (ten [22%] of 46; p=0·72).

INTERPRETATION

Ethanol lock therapy did not prevent CLABSI treatment failure and it increased catheter occlusion. Routine ethanol lock therapy for treatment or secondary prophylaxis is not recommended in this population.

FUNDING

American Lebanese Syrian Associated Charities to St Jude Children's Research Hospital and an Australian Government Research Training Scholarship.

Administration of taurolidine-citrate lock solution for prevention of central venous catheter infection in adult neutropenic haematological patients: a randomised, double-blinded, placebo-controlled trial (TAURCAT)

Background

Catheter-related bloodstream infection (CRBSI) is one of the most frequent complications in patients with cancer who have central venous catheters (CVCs) implanted and is associated with substantial morbidity and mortality. Taurolidine is a non-antibiotic agent with broad-spectrum antimicrobial activity, which has been used as a lock solution to prevent CRBSI in some settings. However, little is known about its usefulness in high-risk adult neutropenic patients with cancer. This prospective randomised clinical trial aims to test the hypothesis that taurolidine-citrate lock solution is more effective than placebo for preventing catheter infection in neutropenic haematological patients.

Methods

This study is a prospective, multicentre, randomised, double-blinded, parallel, superiority, placebo-controlled trial. Patients with haematological cancer who are expected to develop prolonged neutropenia (> 7 days) and who have a non-tunnelled CVC implanted will be randomised to receive prophylactic taurolidine-citrate-heparin solution using a lock technique (study group) or heparin alone (placebo group). The primary endpoint will be bacterial colonisation of the CVC hubs. The secondary endpoints will be the incidence of CRBSI, CVC removal, adverse events, and 30-day case-fatality rate.

Discussion

The lock technique is a preventive strategy that inhibits bacterial colonisation in the catheter hubs, which is the initial step of endoluminal catheter colonisation and the development of infection. Taurolidine is a nontoxic agent that does not develop antibiotic resistance because it acts as an antiseptic rather than an antibiotic. Taurolidine has shown controversial results in the few trials conducted in cancer patients. These studies have important limitations due to the lack of data on adult and/or high-risk neutropenic patients, the type of catheters studied (tunnelled or ports), and the lack of information regarding the intervention (e.g. dwelling of the solution, time, and periodicity of the lock technique). If our hypothesis is proven, the study could provide important solid evidence on the potential usefulness of this preventive procedure in a population at high risk of CRBSI, in whom this complication may significantly impair patient outcome.

Trial registration

ISRCTN, ISRCTN47102251. Registered on 9 September 2015.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-2647-y) contains supplementary material, which is available to authorized users.

The optimal ethanol lock therapy regimen for treatment of biofilm-associated catheter infections: an in-vitro study

BACKGROUND

Ethanol-based lock therapy (LT) solutions are used as an alternative to antibiotics for the conservative management of catheter-related bloodstream infection. However, no clear consensus on regimen or dose has been reached.

AIM

To find the ethanol-based lock solution containing a sufficiently low concentration of ethanol for reduction of the metabolic activity of bacterial and fungal biofilms.

METHODS

Using an in-vitro model, three concentrations of ethanol (25%, 40%, 70%) were tested, with and without 60 IU of heparin, at six different time-points and against 24 h preformed biofilms of Staphylococcus aureus ATCC29213, Staphylococcus epidermidis (clinical isolate), Enterococcus faecalis ATCC33186, Candida albicans ATCC14058, and Escherichia coli ATCC25922. The reduction in the metabolic activity of the biofilm was measured using the tetrazolium salt assay and LT was considered to be successful when metabolic activity fell by >90%. Regrowth inhibition was then tested within 24 h and seven days after each LT regimen only at the ethanol concentration of the most successful LT regimen.

FINDINGS

The most successful LT was achieved with 40% ethanol + 60 IU of heparin only at 24, 72, and 24 h for seven-day regimens (P < 0.05). However, none of the regimens reached 45% RI within seven days of therapy.

CONCLUSION

According to our in-vitro data, an ethanol-based lock solution with 40% ethanol + 60 IU heparin administered daily for 72 h is sufficient to almost eradicate the metabolic activity of bacterial and fungal biofilms. Future studies are needed to study cell regrowth after LT.

Infection of totally implantable venous access devices: A review of the literature

Totally implantable venous access devices, or ports, are essential in the therapeutic management of patients who require long-term intermittent intravenous therapy. Totally implantable venous access devices guarantee safe infusion of chemotherapy, blood transfusion, parenteral nutrition, as well as repeated blood samples. Minimizing the need for frequent vascular access, totally implantable venous access devices also improve the patient's quality of life. Nonetheless, totally implantable venous access devices are not free from complications. Among those, infection is the most relevant, affecting patients' morbidity and mortality-both in the hospital or outpatient setting-and increasing healthcare costs. Knowledge of pathogenesis and risk factors of totally implantable venous access device-related infections is crucial to prevent this condition by adopting proper insertion bundles and maintenance bundles based on the best available evidence. Early diagnosis and prompt treatment of infection are of paramount importance. As a totally implantable venous access device-related infection occurs, device removal or a conservative approach should be chosen in treating this complication. For both prevention and therapy, antimicrobial lock is a major matter of controversy and a promising field for future clinical studies. This article reviews current evidences in terms of epidemiology, pathogenesis and risk factors, diagnosis, prevention, and treatment of totally implantable venous access device-related infections.