Efficacy of antiseptic-impregnated central venous catheters in preventing catheter-related bloodstream infection: a meta-analysis

The antimicrobial effectiveness of chlorhexidine and chlorhexidine-silver sulfadiazine-impregnated central venous catheters against the emerging fungal pathogen Candida auris

BACKGROUND

Candida auris is an emerging multidrug-resistant fungus associated with catheter-related bloodstream infections. In vitro efficacy of chlorhexidine (CHX) and CHX-silver sulfadiazine-impregnated (CHX-S) antimicrobial central venous catheters (CVCs) against C auris was investigated.

METHODS

Minimum inhibitory and bactericidal CHX concentrations were determined against 19 C auris isolates. To assess extraluminal efficacy, segments from CVCs impregnated externally (CHX-S1) and both externally and internally (CHX-S2) were plasma-conditioned for 1- and 6-day, and to assess intraluminal efficacy, CHX-S2 CVCs were preconditioned with saline-lock for 6days, followed by 24-hour C auris inoculation and microbial adherence determination on impregnated and nonimpregnated CVCs.

RESULTS

CHX inhibited all C auris isolates with minimum inhibitory and bactericidal concentrations range of 8 to 128 μg/mL. C auris adherence was reduced on CHX-S1 and CHX-S2 extraluminally by 100% on day 1, 86.96% to 100% on day 7, and intraluminally on CHX-S2 by 56.86% to 90.52% on day 7.

DISCUSSION

CHX and CHX-S CVC performance against C auris observed in this study is consistent with antimicrobial benefits observed in prior preclinical and randomized controlled clinical studies.

CONCLUSIONS

CHX showed strong inhibitory and cidal effects on C auris. CHX-S CVCs proved highly efficacious against this pathogen under in vitro conditions. Additional studies, however, are required to confirm clinical benefit.

Wearable nitric oxide-releasing antibacterial insert for preventing device-associated infections

Medical device-associated infections are a pervasive global healthcare concern, often leading to severe complications. Bacterial biofilms that form on indwelling medical devices, such as catheters, are significant contributors to infections like bloodstream and urinary tract infections. This study addresses the challenge of biofilms on medical devices by introducing a portable antimicrobial catheter insert (PACI) designed to be efficient, biocompatible, and anti-infective. The PACI utilizes nitric oxide (NO), known for its potent antimicrobial properties, to deter bacterial adhesion and biofilm formation. To achieve this, a photoinitiated NO donor, S-nitroso-N-acetylpenicillamine (SNAP), is covalently linked to a polydimethylsiloxane (PDMS) polymer. This design allows for higher NO loading for long-term impact and prevents premature donor leaching, a common challenge with SNAP-blended polymers. The SNAP-PDMS material was applied to a side-glowing fiber optic and connected to a wearable light module emitting 450 nm light, creating a functional antimicrobial insert. Activation of the fiber optic, accomplished with a one-click mechanism, enables real-time NO release, maintaining controlled NO levels for a minimum of 24  hours. The therapeutic levels of NO released via photocatalysis from the PACI demonstrated remarkable efficacy, with >90 % reduction in bacterial viability against S. aureus, S. epidermidis, and P. mirabilis without any cytotoxic impact on mammalian cells. This study underscores the potential of the NO-releasing insert in clinical settings, providing a portable and adaptable solution for preventing catheter-associated infections.

A case report of cardiac tamponade after a road accident: think beyond trauma

Background

Cardiac tamponade is a life-threatening compression of the heart caused by the accumulation of fluid in the pericardial sac. Although central venous catheters (CVCs) are essential in modern medicine, they carry a certain risk of complications including cardiac tamponade.

Case summary

A 12-year-old female was involved in a road accident reporting multiple severe traumatic injuries, including a left humerus fracture and subdural haemorrhage. After 2 days in the intensive care unit, she suddenly developed hypotension and cardiac tamponade was diagnosed. Analysis of the pericardial fluid showed high glucose levels comparable to the parenteral nutrition that she was receiving. Retraction of the CVC allowed resolution of the effusion.

Discussion

Cardiac tamponade is a rare but serious adverse event after CVC insertion, mostly among younger patients. Awareness of this risk allows physicians to promptly recognize and treat this dangerous complication.

Compliance with good practice guidelines for the prevention of vascular access infections: the multi-centre PHYDEL survey in French haemodialysis units

BACKGROUND

French guidelines for the prevention of vascular access infections in a haemodialysis setting were released in 2005. Compliance with these guidelines is currently unknown. The aim of this study was to assess compliance with the guidelines for vascular access infection prevention in French haemodialysis units, and to describe the difficulties reported.

METHODS

A cross-sectional survey was conducted between March and December 2019 in 200 haemodialysis units in France, selected at random. Data were collected via questionnaire, completed by telephone interview with an infection control practitioner. A practice was deemed compliant when >85% of units declared that they always complied with the guidelines.

RESULTS

In total, 103 units (51.5%) agreed to participate. Most practices complied with the guidelines; however, some practices did not reach the 85% compliance threshold for working in pairs when connecting central venous catheter (CVC) lines, performing hand hygiene before disconnecting lines, rinsing antiseptic soap before painting CVC exit site or arteriovenous fistula (AVF) puncture site, allowing antiseptic paint to dry, handling CVC branches with antiseptic impregnated gauze, performing hand hygiene after AVF compression with gloves, wearing protective eyewear when connecting/disconnecting CVC or when puncturing AVF, and wearing a gown when puncturing AVF. The most frequently reported difficulties were understaffing, difficulties with skin preparation because of exit site skin damage, and lack of buttonhole technical expertise.

CONCLUSIONS

Despite good overall compliance, this survey highlights some shortcomings in compliance with infection prevention guidelines, which could be associated with either higher risk of vascular access infection or increased blood-borne virus transmission.

Strategies to Prevent Infections in Dialysis Patients

Infections are the second leading cause of death among patients with end-stage kidney disease, behind only cardiovascular disease. In addition, patients on chronic dialysis are at a higher risk for acquiring infection caused by multidrug-resistant organisms and for death resulting from infection owing to their likelihood of requiring treatment that involves invasive devices, their frequent exposure to antibiotics, and their impaired immunity. Vascular access is a major risk factor for bacteremia, hospitalization, and mortality among hemodialysis (HD) patients. Catheter-related bacteremia is the most severe central venous catheter (CVC)-related infection and increases linearly with the duration of catheter use. Given the high prevalence of CVC use and its direct association with catheter-related bacteremia, which adversely impacts morbidity and mortality rates among HD patients, several prevention measures aimed at reducing the rates of CVC-related infection have been proposed and implemented. As a result, a large number of clinical trials, systematic reviews, and meta-analyses have been conducted to assess the effectiveness, clinical applicability, and long-term adverse effects of such measures. Peritoneal dialysis chronic treatment without the occurence of peritonitis is rare. Although most cases of peritonitis can be treated adequately with antibiotics, some cases are complicated by hospitalization or a temporary or permanent need to abstain from using the peritoneal dialysis catheter. Severe and long-lasting peritonitis can lead to peritoneal membrane failure, requiring the treatment method to be switched to HD. Some measures as patients training, early diagnosis, and choice of antibiotics can contribute to the successful treatment of peritonitis. Finally, medical directors are key leaders in infection prevention and are an important resource to implement programs to monitor and improve infection prevention practices at all levels within the dialysis clinic.

Effect of the Preparation Method on the Properties of Eugenol-Doped Titanium Dioxide (TiO2) Sol-Gel Coating on Titanium (Ti) Substrates

The focus of this study was the preparation of sol-gel titanium dioxide (TiO2) coatings, by the dip-coating technique, on Ti6Al4V (TiGr5) and specific Ti implant substrates. In order to confer antibacterial properties to the layers, Eugenol was introduced in the coatings in two separate ways: firstly by introducing the Eugenol in the sol (Eug-TiO2), and secondly by impregnating into the already deposed TiO2 coating (TiO2/Eug). Optimization of Eugenol concentration as well as long term were performed in orderboth short- and long-term Eugenol concentration was performed to investigate the prepared samples thoroughly. The samples were investigated by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization curves (PDP). To investigate their resistance against Gram-negative Escherichia coli bacteria, microbiological analysis was performed on coatings prepared on glass substrates. Structural studies (FT-IR analysis, Raman spectroscopy) were performed to confirm Eugenol-TiO2 interactions. Coating thicknesses and adhesion were also determined for all samples. The results show that Eug-TiO2 presented with improved anticorrosive effects and significant antibacterial properties, compared to the other investigated samples.

Surveillance of central line associated bloodstream infection (CLABSI) - comparison of current (CDC/NHSN) and modified criteria: A prospective study

Background and Aims

There is a huge load of central line-associated bloodstream infection (CLABSI) being reported in developing countries, with increased mortality and healthcare costs. Effective surveillance is a must to reduce the incidence of CLABSI. The current criteria (Centre for Disease Control and Prevention/National Healthcare Safety Network [CDC/NHSN]) for CLABSI surveillance have their own shortcomings. For diagnosing CLABSI, current CDC/NHSN CLABSI surveillance criteria are laborious and time consuming with low predictive power. Hence, modified criteria have been postulated, which are simple and implementable at resource-constrained setups. The primary objective was to compare modified criteria with CDC criteria. The secondary objective was to determine the prevalence of CRBSI.

Material and Methods

A total of 98 patients with central line in situ or having the central venous line removed ≤24 hrs prior to the date of the event were enrolled. Paired blood cultures were obtained and results were analyzed using differential time to positivity.

Results

The incidence of CLBSI was 8.16% and the device utilization rate was 11.6%. The negative predictive value of both the surveillance criteria was found to be excellent and comparable (96.2% for modified criteria and 97.1% for CDC criteria), therefore both can be used for screening purposes. AUC for current CDC/NHSN criteria was better than modified criteria (0.76 versus 0.66, P < 0.0001), suggesting it to be a better criterion for surveillance of CLABSI.

Conclusion

Modified criteria were not superior to CDC/NHSN criteria for surveillance. Thus, there is a scope of improving the modified criteria for the purpose of surveillance. CLBSI load was higher; CLABSI bundle for prevention is thus highly recommended.

Quality Improvement Initiative in a Community Hospital to Reduce Central Line Device Utilization Rate

Background The intensive care unit (ICU) in a community hospital in southwest Minnesota saw a steady increase in central line-associated bloodstream infections (CLABSI) and an increase in the utilization of central lines. The baseline CLABSI rate was 11.36 at the start of the project, which was the highest in the last five years. The corresponding device utilization rate (DUR) was 64%, which increased from a pre-COVID pandemic rate of 45%. Aim The aim of this project was to decrease the ICU DUR by 37.5% from a baseline of 64% to 40% within six months without adversely impacting staff satisfaction. Methods A multidisciplinary team using the define, measure, analyze, improve, and control (DMAIC) methodology reviewed the potential causes of the increased use of central lines in the ICU. The team identified the following major causal themes: process, communication, education, and closed-loop feedback. Once the root causes were determined, suitable countermeasures were identified and implemented to address these barriers. These included reviewing current guidelines, enhanced care team rounding, staff education, and the creation of a vascular access indication algorithm. The team met biweekly to study the current state, determine the future state, evaluate feedback, and guide implementation. Results The pandemic saw a surge in the number of severely ill patients in the ICU, which may have caused an increase in the DUR. The project heightened the awareness of the increased DUR and its impact on the CLABSI rate. The initiation of discussion around this project led to an immediate decline in DUR via increased awareness and focus. As interventions were introduced and implemented, the DUR continued to decrease at a steady rate. Post implementation, the DUR met the project goal of less than 40%. The team continued to track progress and monitor feedback. The DUR continued to meet the goal for three months post implementation. Since the start of the project, there have been no CLABSI events reported. This effort has positively impacted safety and patient outcomes. Conclusions Through a defined process, the central line utilization rate in our ICU was decreased to 37.5% to meet the target goal and has been sustained.

Silver as an Antibiotic-Independent Antimicrobial: Review of Current Formulations and Clinical Relevance

Background: The increase of multi-drug-resistant organisms has revived the use of silver as an alternative antibiotic-independent antimicrobial. Although silver's multimodal mechanism of action provides low risk for bacterial resistance, high local and uncontrolled concentrations have shown toxicity. This has resulted in efforts to develop novel silver formulations that are safer and more predictable in their application. Optimization of silver as an antimicrobial is crucial given the growing resistance profile against antibiotics. This article reviews formulations of silver used as antimicrobials, focusing on the mechanisms of action, potential for toxicity, and clinical applications. Methods: A search of four electronic databases (PubMed, Embase, MEDLINE, and Cochrane Library) was conducted for relevant studies up to January 2022. Searches were conducted for the following types of silver: ionic, nanoparticles, colloidal, silver nitrate, silver sulfadiazine, silver oxide, silver carboxylate, and AQUACEL^® (ConvaTec, Berkshire, UK). Sources were compiled based on title and abstract and screened for inclusion based on relevance and study design. Results: A review of the antimicrobial activity and uses of ionic silver, silver nanoparticles, colloidal silver, silver nitrate, silver sulfadiazine, silver oxide, Aquacel, and silver carboxylate was conducted. The mechanisms of action, clinical uses, and potential for toxicity were studied, and general trends between earlier and more advanced formulations noted. Conclusions: Early forms of silver have more limited utility because of their uncontrolled release of silver ions and potential for systemic toxicity. Multiple new formulations show promise; however, there is a need for more prospective in vivo studies to validate the clinical potential of these formulations.

Smartphone compatible nitric oxide releasing insert to prevent catheter-associated infections

A large fraction of nosocomial infections is associated with medical devices that are deemed life-threatening in immunocompromised patients. Medical device-related infections are a result of bacterial colonization and biofilm formation on the device surface that affects >1 million people annually in the US alone. Over the past few years, light-based antimicrobial therapy has made substantial advances in tackling microbial colonization. Taking the advantage of light and antibacterial properties of nitric oxide (NO), for the first time, a robust, biocompatible, anti-infective approach to design a universal disposable catheter disinfection insert (DCDI) that can both prevent bacterial adhesion and disinfect indwelling catheters in situ is reported. The DCDI is engineered using a photo-initiated NO donor molecule, incorporated in polymer tubing that is mounted on a side glow fiber optic connected to an LED light source. Using a smartphone application, the NO release from DCDI is photoactivated via white light resulting in tunable physiological levels of NO for up to 24 h. When challenged with microorganisms S. aureus and E. coli, the NO-releasing DCDI statistically reduced microbial attachment by >99% versus the controls with just 4 h of exposure. The DCDI also eradicated ∼97% of pre-colonized bacteria on the CVC catheter model demonstrating the ability to exterminate an established catheter infection. The smart, mobile-operated novel universal antibacterial device can be used to both prevent catheter infections or can be inserted within an infected catheter to eradicate the bacteria without complex surgical interventions. The therapeutic levels of NO generated via illuminating fiber optics can be the next-generation biocompatible solution for catheter-related bloodstream infections.

Heparin versus 0.9% sodium chloride locking for prevention of occlusion in central venous catheters in adults

BACKGROUND

Intermittent locking of central venous catheters (CVCs) is undertaken to help maintain their patency and performance. There are systematic variations in care: some practitioners use heparin (at different concentrations), whilst others use 0.9% sodium chloride (normal saline). This review looks at the effectiveness and safety of intermittent locking with heparin compared to normal saline, to see if the evidence establishes whether one is better than the other. This is an update of an earlier Cochrane Review.

OBJECTIVES

To evaluate the benefits and harms of intermittent locking of CVCs with heparin versus normal saline in adults to prevent occlusion.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search date was 20 October 2021.

SELECTION CRITERIA

We included randomised controlled trials in adults ≥ 18 years of age with a CVC that compared intermittent locking with heparin at any concentration versus normal saline. We excluded studies on infants and children from this review.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcomes were occlusion of CVCs and duration of catheter patency. Our secondary outcomes were CVC-related bloodstream infections and CVC-related colonisation, mortality, haemorrhage, heparin-induced thrombocytopaenia, CVC-related thrombosis, number of additional CVC insertions, abnormality of coagulation profile and allergic reactions to heparin. We used GRADE to assess the certainty of evidence for each outcome.

MAIN RESULTS

We identified one new RCT with 30 participants for this update. We included a total of 12 RCTs with 2422 participants. Data for meta-analysis were available from all RCTs. We noted differences in methods used by the included studies and variation in heparin concentrations (10 to 5000 IU/mL), time to follow-up (1 to 251.8 days), and the unit of analysis used (participant, catheter, line access). Five studies included ICU (intensive care unit) patients, two studies included oncology patients, and the remaining studies included miscellaneous patients (chronic kidney disease, haemodialysis, home care patients, etc.). Primary outcomes Overall, combined results may show fewer occlusions with heparin compared to normal saline but this is uncertain (risk ratio (RR) 0.70, 95% confidence interval (CI) 0.51 to 0.95; 10 studies; 1672 participants; low-certainty evidence). We pooled studies that used participant or catheter as the unit of analysis. We carried out subgroup analysis by unit of analysis. No clear differences were detected after testing for subgroup differences (P = 0.23). We found no clear evidence of a difference in the duration of catheter patency with heparin compared to normal saline (mean difference (MD) 0.44 days, 95% CI -0.10 to 0.99; 6 studies; 1788 participants; low-certainty evidence). Secondary outcomes We found no clear evidence of a difference in the following outcomes: CVC-related bloodstream infections (RR 0.66, 95% CI 0.08 to 5.80; 3 studies; 1127 participants; very low-certainty evidence); mortality (RR 0.76, 95% CI 0.44 to 1.31; 3 studies; 1100 participants; very low-certainty evidence); haemorrhage (RR 1.54, 95% CI 0.41 to 5.74; 3 studies; 1197 participants; very low-certainty evidence); or heparin-induced thrombocytopaenia (RR 0.21, 95% CI 0.01 to 4.27; 3 studies; 443 participants; very low-certainty evidence). The main reasons for downgrading the certainty of evidence for the primary and secondary outcomes were unclear allocation concealment, suspicion of publication bias, imprecision and inconsistency.

AUTHORS' CONCLUSIONS

Given the low-certainty evidence, we are uncertain whether intermittent locking with heparin results in fewer central venous catheter occlusions than intermittent locking with normal saline in adults. Low-certainty evidence suggests that heparin may have little or no effect on catheter patency duration. Although we found no evidence of differences in safety (CVC-related bloodstream infections, mortality, or haemorrhage), the combined studies were not powered to detect rare adverse events such as heparin-induced thrombocytopaenia. Further research conducted over longer periods would reduce the current uncertainties.

Continuous antimicrobial mechanism of dispersible hydroxyapatite nanoparticles doped with zinc ions for percutaneous device coatings

Percutaneous devices-indwelling catheters-related infections are serious clinical incidents. It is accordingly necessary to develop anti-infective coating materials suitable for the devices for long-term effectiveness. In our research group, highly dispersible and crystalline hydroxyapatite (HAp) nanoparticles doped with metallic or halogen ions possessing antibacterial activities have been developed. In this study, antibacterial, dispersible, and crystalline zinc (Zn)-doped hydroxyapatite [Zn(15)-HAp] nanoparticles substituted with 13.5% Zn content [Zn/(Zn + Ca) × 100] were prepared by a wet chemical method using an anti-sintering agent through calcination. Antibacterial activities of Zn(15)-HAp nanoparticles were evaluated using Escherichia coli (E. coli) and Staphylococcus aureus. The survival rates of the bacteria on Zn(15)-HAp nanoparticles were significantly lower than that on normal HAp (nHAp) coated surfaces, while no influences were observed on proliferation of L929 cells. Even after soaking Zn(15)-HAp nanoparticles in PBS for 2 weeks, the antibacterial activities against E. coli were maintained at a similar level to a 20 min soaking. The bacterial death was related to not only ion-exchange phenomenon between Zn and magnesium ions but also accumulation of reactive oxygen species (ROS) in the cells. Allergic-like reactions-anaphylactoid reactions-might not readily occur with Zn(15)-HAp nanoparticles because the amounts of histamine released from HMC-1 cells co-cultured with nanoparticles were not significantly different to that of nHAp, but were statistically much lower than that of chlorhexidine.

Intraperitoneal Hematoma After Femoral Catheterization: A Case Report and Literature Review

Central venous catheters (CVCs) are often crucial in managing severely ill patients, especially those in the intensive care unit. It is estimated that over 5 million CVCs are inserted per year in the United States. The internal jugular, subclavian, or femoral veins are the most used access sites. The catheter is advanced until its tip lies within the proximal third of the superior vena cava, the right atrium, or the inferior vena cava. Unfortunately, the use of CVCs is not without its drawbacks, and multiple immediate and delayed complications have been described. Herein, we report a case of a 70-year-old female with a past medical history significant for chronic obstructive pulmonary disease, coronavirus disease 2019, pneumonia, type 2 diabetes mellitus, and hypertension, who presented to the emergency department from a skilled nursing facility with a two-day history of dyspnea. She was later diagnosed with an intraperitoneal hematoma, an uncommon complication caused by a CVC placement.

Effect of Central Line Duration and Other Risk Factors on Central Line-Associated Bloodstream Infection in Severe Adult Burns Patients at a Large Tertiary Referral Burns Centre: A 5-Year Retrospective Study

Central line-associated bloodstream infection (CLABSI) and catheter-related bloodstream infection (CLABSI with a positive catheter tip culture, CRBSI) are preventable causes of morbidity and mortality for severe adult burns patients. Routine central line changes as a CLABSI prevention strategy in burns patients is controversial due to the paucity of evidence to guide the appropriate timing of line changes. This study aimed to address this evidence gap by investigating risk factors associated with central line sepsis, including the duration of central line insertion, in a population of severe adult burns patients (burns involving ≥20% total body surface area (TBSA)) admitted to the Royal Brisbane and Women's Hospital Intensive Care Unit over five years (2015-2019 inclusive). On multivariate analysis, central line duration and burn TBSA were identified as independent risk factors for CLABSI, with central line duration the most significant predictor (p = 0.0008; OR 1.177, 95% CI 1.072-1.299). No risk factor independently predicted CRBSI. CLABSI detection occurred a median of 8.5 days (IQR 6.0-11.0) post central line insertion. These findings suggest further research to assess the efficacy of routine line changes prior to the at-risk period of 6-11 days post central line insertion in reducing CLABSI in severe adult burns patients may be beneficial.

Chlorhexidine - a commonly used but often neglected culprit of dialysis associated anaphylactic reactions (case report)

BACKGROUND

Hemodialysis-associated anaphylactic reactions are rare and frequently complex in nature due to the sheer number of possible culprit agents. Unfortunately, dialysis is often unavoidable or strictly essential for life-saving solute clearance or fluid removal in patients with end stage kidney failure and those with severe acute kidney injury. It is of utmost importance that the culprit agent is identified and avoided to allow continuation of dialysis treatment as needed.

CASE PRESENTATION

We present 2 cases of hemodialysis-associated anaphylactic reactions. These patients developed anaphylactic reactions peri-dialysis and were initially suspected to have dialyser reactions. They were investigated in a controlled healthcare setting and possible culprit agents were systemically identified and eliminated. They both underwent allergy testing and were diagnosed with chlorhexidine allergy. Of note, Case 1 was an incident dialysis patient at the time of presentation and Case 2 was a prevalent dialysis patient. This suggests that the time from initial sensitization to reaction may not always be helpful in determining if a particular agent is the culprit of an anaphylactic reaction. In both cases, the patients were dialysed through a tunnelled dialysis catheter. We postulate that the presence of an exit site, which represents a compromise to the integrity of the skin's epidermal barrier, may have a significant role in the development of these reactions. As chlorhexidine is a widely used disinfectant in hemodialysis, it is imperative that we consider it as a possible culprit agent when these reactions arise. To our knowledge, there are no other reported cases of anaphylaxis secondary to chlorhexidine use in dialysis patients other than a previous report in 2017. Our report also highlights the possibility of these reactions occurring more frequently in patients with damaged epidermal barriers and in patients exposed to higher environmental concentrations of chlorhexidine. These are novel concepts that can be explored with further research.

CONCLUSION

Chlorhexidine associated anaphylactic reactions can occur in the peri-dialysis setting and a high index of suspicion is paramount to diagnosis.

Central Venous Catheters for Hemodialysis-the Myth and the Evidence

Hemodialysis-central venous catheter (HD-CVC) insertion is a most often performed procedure, with approximately 80% of patients with end-stage kidney disease in the United States initiating kidney replacement therapy through a HD-CVC. Certain adverse events arising from HD-CVC placement, including catheter-related bloodstream infections (CR-BSIs), thrombosis, and central vein stenosis, can complicate the clinical course of patients and lead to considerable financial impact on the health care system. Medical professionals with different training backgrounds are responsible for performing this procedure, and therefore, comprehensive operator guidelines are crucial to improve the success rate of HD-CVC insertion and prevent complications. In this review article, we not only discuss the basic principles behind the use of HD-CVCs but also address frequently asked questions and myths regarding catheter asepsis, length selection, tip positioning, and flow rate assessment.

Impact of Healthcare-Associated Infections Connected to Medical Devices-An Update

Healthcare-associated infections (HAIs) are caused by nosocomial pathogens. HAIs have an immense impact not only on developing countries but also on highly developed parts of world. They are predominantly device-associated infections that are caused by the planktonic form of microorganisms as well as those organized in biofilms. This review elucidates the impact of HAIs, focusing on device-associated infections such as central line-associated bloodstream infection including catheter infection, catheter-associated urinary tract infection, ventilator-associated pneumonia, and surgical site infections. The most relevant microorganisms are mentioned in terms of their frequency of infection on medical devices. Standard care bundles, conventional therapy, and novel approaches against device-associated infections are briefly mentioned as well. This review concisely summarizes relevant and up-to-date information on HAIs and HAI-associated microorganisms and also provides a description of several useful approaches for tackling HAIs.

Subclavian Artery Injury Following Central Venous Catheter Placement

Mechanical complications following central venous catheterization are not uncommon. We discuss a case of iatrogenic intra-arterial central venous catheter placement requiring neck exploration in a 93-year-old woman. The catheter was inadvertently passed through the jugular vein and into the right subclavian artery by a junior surgical resident. Adequate technique and supervision, ultrasound guidance, and immediate diagnostic workup in the event of suspected arterial injury are factors necessary for physicians to minimize complications and provide safe medical treatment.

Self-Limiting Mussel Inspired Thin Antifouling Coating with Broad-Spectrum Resistance to Biofilm Formation to Prevent Catheter-Associated Infection in Mouse and Porcine Models

Catheter-associated urinary tract infections (CAUTIs) are one of the most commonly occurring hospital-acquired infections. Current coating strategies to prevent catheter-associated biofilm formation are limited by their poor long-term efficiency and limited applicability to diverse materials. Here, the authors report a highly effective non-fouling coating with long-term biofilm prevention activity and is applicable to diverse catheters. The thin coating is lubricous, stable, highly uniform, and shows broad spectrum prevention of biofilm formation of nine different bacterial strains and prevents the migration of bacteria on catheter surface. The coating method is adapted to human-sized catheters (both intraluminal and extraluminal) and demonstrates long-term biofilm prevention activity over 30 days in challenging conditions. The coated catheters are tested in a mouse CAUTI model and demonstrate high efficiency in preventing bacterial colonization of both Gram-positive and Gram-negative bacteria. Furthermore, the coated human-sized Foley catheters are evaluated in a porcine CAUTI model and show consistent efficiency in reducing biofilm formation by Escherichia coli (E. coli) over 95%. The simplicity of the coating method, the ability to apply this coating on diverse materials, and the high efficiency in preventing bacterial adhesion increase the potential of this method for the development of next generation infection resistant medical devices.

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.

Multifunctional Synthetic Amphiphile for Niche Therapeutic Applications: Mitigation of MRSA Biofilms and Potential in Wound Healing

The relentless menace of implant- and skin wound-associated infections caused by methicillin-resistant Staphylococcus aureus (MRSA) biofilms demands the design of therapeutics that have an edge over conventional antibiotics. The present study reports the potential of pluri-active amphiphiles having a 12-carbon alkyl chain and a salicaldehyde head group (C1) or a napthaldehyde head group (C2) in mitigating wound site- and implant-associated MRSA biofilms and as a topical wound healing agent. The amphiphiles impeded S. aureus MRSA 100 biofilm formation on collagen both on extraneous addition and on impregnation into collagen and inflicted damage to MRSA cells embedded in collagen matrix infused with simulated wound fluid, with C1 being more potent than C2. Adhesion of the MRSA biofilm was hampered on C1-coated orthopedic stainless-steel wire, while eluates from C1-coated wires were non-toxic to HEK 293 cells, highlighting the prospect of C1 as an implant-associated antibacterial coating. Upon treatment with C1, expression of the adhesin fnbA gene was low in the MRSA biofilm and downregulated in non-adherent MRSA cells, while δ-toxin (hld) gene expression in the MRSA biofilm increased, implying that C1 hindered cell-cell adhesion and planktonic-biofilm transition and also reduced biofilm adhesion. Oral administration of C1 (300 and 1000 mg/kg) was non-toxic to BALB/c mice as evidenced in stable hematological parameters and normal histopathological features of vital organs. Topical application of C1 (50 and 100 mg/kg) on a skin excision wound in female BALB/c mice resulted in effective wound closure, fibrous tissue proliferation, and tissue reorganization. Confocal microscopy revealed that topical application of C1 in an ex vivo murine skin explant could alleviate invasion of skin by MRSA, while solution-based studies indicated subdued MRSA adhesion onto the skin explants. The pluri-active synthetic amphiphile C1 provides a framework for developing antibacterials that hold translational potential as a therapeutic for implant- and skin wound-associated MRSA infections.

Prevention of Complications in the Cardiac Intensive Care Unit: A Scientific Statement From the American Heart Association

Contemporary cardiac intensive care units (CICUs) have an increasing prevalence of noncardiovascular comorbidities and multisystem organ dysfunction. However, little guidance exists to support the development of best-practice principles specific to the CICU. This scientific statement evaluates strategies to avoid the potentially preventable complications encountered within contemporary CICUs, focusing on those that are most applicable to the CICU environment. This scientific statement reviews evidence-based practices derived in non–CICU populations, assesses their relevance to CICU practice, and highlights key knowledge gaps warranting further investigation to attenuate patient risk.

Effects of blood flow on the antibacterial efficacy of chlorhexidine and silver sulfadiazine coated central venous catheter: A simulation-based pilot study

BACKGROUND

Chlorhexidine and silver sulfadiazine coated central venous catheters (CSS-CVC) may cause loss of antimicrobial efficacy due to friction between the CVC surface and sheer stress caused by the blood flow. Therefore, the aim of this study was to investigate the antibacterial efficacy of CSS-CVC at various flow rates using a bloodstream model.

METHODS

Each CVC was subjected to various flow rates (0.5, 1, 2, and 4 L/min) and wear-out times (0, 24, 48, 72, 96, and 120 hours), and the optical density (OD) 600 after a Staphylococcus aureus incubation test was used to determine the antibacterial effect of CSS-CVC.

RESULTS

In the 0.5 L/min group, there was no significant change in the OD600 value up to 120 hours compared with the baseline OD600 value for CSS-CVC (P > .467). However, the OD600 values of CSS-CVC in the 1 L/min (P < .001) and 2 L/min (P < .001) groups were significantly reduced up to 72 hours, while that in the 4 L/min (p < 0.001) group decreased rapidly up to 48 hours.

CONCLUSION

This study suggests that there is a doubt whether sufficient antibacterial function can be maintained with prolonged duration of catheter placement.

In vitro evaluation of contact-active antibacterial efficacy of Ti-Al-V alloys coated with the antimicrobial agent PHMB

Immobilized polycationic substances on biomaterial surfaces kill adhering bacteria upon contact and are considered a promising non-antibiotic alternative. Unfortunately, there is no generally accepted in vitro method for quantitatively evaluating the antibacterial efficacy of contact-active non-leachable antimicrobial surfaces. Moreover, guidelines of generally accepted international industrial standards do not reflect the basic principle of bacterial contamination and/or are performed in the presence of a solid covering material. Therefore, in the present study, six bacterial adherence tests on non-porous surfaces with no covering material were compared with respect to their efficacy and reproducibility, as well as to evaluate the bactericidal contact-killing of relevant device-associated slime-producing bacteria using antimicrobially coated Ti6Al4V surfaces with positively-charged poly(hexamethylene biguanide) hydrochloride (PHMB). After direct bacterial inoculation to simulate a perioperative infection, non-leaching PHMB reacts bactericidally against the slime-producing bacteria Staphylococcus aureus, Staphylococcus epidermidis, and Pseudomonas aeruginosa after surface contact. The 6-h drop technique was found to be a suitable method to quantitatively evaluate contact-active antibacterial surfaces. Adjunctively, however, damage of bacterial membrane integrity should be confirmed by LIVE/DEAD staining and the presence of non-leaching agents. STATEMENT OF SIGNIFICANCE: Unintentional perioperative bacterial adhesion to implant surfaces can generate biomaterial-associated infections. Adhered bacteria produce biofilms that protect them from antibiotic attack, which may be complicated by possible antibiotic resistance. Polycationic surfaces can prevent such unwanted biofilm formation by killing bacteria upon initial contact. Unfortunately, no reliable in vitro methods exist to evaluate the efficacy of contact-active antimicrobial surfaces. In this study, we show that the 6-h drop technique may be a suitable method to evaluate positively-charged contact-killing surfaces. Identification of suitable screening assays for evaluating the bactericidal efficacy of non-leachable antimicrobial agents will greatly improve this newly developing field as a prophylactic alternative to postoperative treatment of implant-associated infections by antibiotics.

The median and the mode as robust meta-analysis estimators in the presence of small-study effects and outliers

Meta‐analyses based on systematic literature reviews are commonly used to obtain a quantitative summary of the available evidence on a given topic. However, the reliability of any meta‐analysis is constrained by that of its constituent studies. One major limitation is the possibility of small‐study effects, when estimates from smaller and larger studies differ systematically. Small‐study effects may result from reporting biases (ie, publication bias), from inadequacies of the included studies that are related to study size, or from reasons unrelated to bias. We propose two estimators based on the median and mode to increase the reliability of findings in a meta‐analysis by mitigating the influence of small‐study effects. By re‐examining data from published meta‐analyses and by conducting a simulation study, we show that these estimators offer robustness to a range of plausible bias mechanisms, without making explicit modelling assumptions. They are also robust to outlying studies without explicitly removing such studies from the analysis. When meta‐analyses are suspected to be at risk of bias because of small‐study effects, we recommend reporting the mean, median and modal pooled estimates.

The 100 top-cited systematic reviews/meta-analyses in central venous catheter research: A PRISMA-compliant systematic literature review and bibliometric analysis

OBJECTIVE

The central venous catheter is used extensively worldwide. The purpose of this bibliometric analysis was to identify the 100 top-cited systematic reviews/meta-analyses in the literature on central venous catheters and to capture the most important trends in this area of research.

RESEARCH METHODOLOGY

A search was performed in the Web of Science Core Collection on studies published prior to November 12th, 2019. The search terms included central venous catheter, systematic review and meta-analysis. Retrieved studies were ranked by citation number and selected by two of the authors. Information such as citation number, author, institution, country and year of publication was collected.

RESULTS

The 100 top-cited studies published between 1992 and 2017 were reviewed, with the largest proportion published in 2008 (n = 17). The number of citations ranged from 14 to 660. The country with the largest number of studies was the United States of America (n = 36). Critical Care Medicine published the greatest number of these studies (n = 13). The largest number of these studies were focused on central venous catheter-related infection (n = 56) and thrombosis (n = 19).

CONCLUSION

Developed countries were the most productive in the field of central venous catheters. Most meta-analyses focused on complications associated with central-venous catheters such as infection and thrombosis.

Indian Society of Critical Care Medicine Position Statement for Central Venous Catheterization and Management 2020

BACKGROUND AND PURPOSE

Short-term central venous catheterization (CVC) is one of the commonly used invasive interventions in ICU and other patient-care areas. Practice and management of CVC is not standardized, varies widely, and need appropriate guidance. Purpose of this document is to provide a comprehensive, evidence-based and up-to-date, one document source for practice and management of central venous catheterization. These recommendations are intended to be used by critical care physicians and allied professionals involved in care of patients with central venous lines.

METHODS

This position statement for central venous catheterization is framed by expert committee members under the aegis of Indian Society of Critical Care Medicine (ISCCM). Experts group exchanged and reviewed the relevant literature. During the final meeting of the experts held at the ISCCM Head Office, a consensus on all the topics was made and the recommendations for final document draft were prepared. The final document was reviewed and accepted by all expert committee members and after a process of peer-review this document is finally accepted as an official ISCCM position paper.Modified grade system was utilized to classify the quality of evidence and the strength of recommendations. The draft document thus formulated was reviewed by all committee members; further comments and suggestions were incorporated after discussion, and a final document was prepared.

RESULTS

This document makes recommendations about various aspects of resource preparation, infection control, prevention of mechanical complication and surveillance related to short-term central venous catheterization. This document also provides four appendices for ready reference and use at institutional level.

CONCLUSION

In this document, committee is able to make 54 different recommendations for various aspects of care, out of which 40 are strong and 14 weak recommendations. Among all of them, 42 recommendations are backed by any level of evidence, however due to paucity of data on 12 clinical questions, a consensus was reached by working committee and practice recommendations given on these topics are based on vast clinical experience of the members of this committee, which makes a useful practice point. Committee recognizes the fact that in event of new emerging evidences this document will require update, and that shall be provided in due time.

ABBREVIATIONS LIST

ABHR: Alcohol-based hand rub; AICD: Automated implantable cardioverter defibrillator; BSI: Blood stream infection; C/SS: CHG/silver sulfadiazine; Cath Lab: Catheterization laboratory (Cardiac Cath Lab); CDC: Centers for Disease Control and Prevention; CFU: Colony forming unit; CHG: Chlorhexidine gluconate; CL: Central line; COMBUX: Comparison of Bedside Ultrasound with Chest X-ray (COMBUX study); CQI: Continuous quality improvement; CRBSI: Catheter-related blood stream infection; CUS: Chest ultrasonography; CVC: Central Venous Catheter; CXR: Chest X-ray; DTTP: Differential time to positivity; DVT: Deep venous thrombosis; ECG: Electrocardiography; ELVIS: Ethanol lock and risk of hemodialysis catheter infection in critically ill patients; ER: Emergency room; FDA: Food and Drug Administration; FV: Femoral vein; GWE: Guidewire exchange; HD catheter: Hemodialysis catheter; HTS: Hypertonic saline; ICP: Intracranial pressure; ICU: Intensive Care Unit; IDSA: Infectious Disease Society of America; IJV: Internal jugular vein; IPC: Indian penal code; IRR: Incidence rate ratio; ISCCM: Indian Society of Critical Care Medicine; IV: Intravenous; LCBI: Laboratory confirmed blood stream infection; M/R: Minocycline/rifampicin; MBI-LCBI: Mucosal barrier injury laboratory-confirmed bloodstream infection; MRSA: Methicillin-resistant Staphylococcus aureus; NHS: National Health Service (UK); NHSN: National Healthcare Safety Network (USA); OT: Operation Theater; PICC: Peripherally-inserted central catheter; PIV: Peripheral intravenous line; PL: Peripheral line; PVI: Povidone-iodine; RA: Right atrium; RCT: Randomized controlled trial; RR: Relative risk; SCV/SV: Subclavian vein; ScVO2: Central venous oxygen saturation; Sn: Sensitivity; SOP: Standard operating procedure; SVC: Superior vena cava; TEE: Transesophageal echocardiography; UPP: Useful Practice Points; USG: Ultrasonography; WHO: World Health Organization.

HOW TO CITE THIS ARTICLE

Javeri Y, Jagathkar G, Dixit S, Chaudhary D, Zirpe KG, Mehta Y, et al. Indian Society of Critical Care Medicine Position Statement for Central Venous Catheterization and Management 2020. Indian J Crit Care Med 2020;24(Suppl 1):S6-S30.

Systems Modeling Approach for Reducing the Risk of Healthcare-Associated Infections

Healthcare-associated infections (HAIs) are a major cause of concern because of the high levels of associated morbidity, mortality, and cost. In addition, children and intensive care unit (ICU) patients are more vulnerable to these infections due to low levels of immunity. Various medical interventions and statistical process control techniques have been suggested to counter the spread of these infections and aid early detection of an infection outbreak. Methods such as hand hygiene help in the prevention of HAIs and are well-documented in the literature. This chapter demonstrates the utilization of a systems methodology to model and validate factors that contribute to the risk of HAIs in a pediatric ICU. It proposes an approach that has three unique aspects: it studies the problem of HAIs as a whole by focusing on several HAIs instead of a single type, it projects the effects of interventions onto the general patient population using the system-level model, and it studies both medical and behavioral interventions and compares their effectiveness. This methodology uses a systems modeling framework that includes simulation, risk analysis, and statistical techniques for studying interventions to reduce the transmission likelihood of HAIs.

Polymeric Composites with Silver (I) Cyanoximates Inhibit Biofilm Formation of Gram-Positive and Gram-Negative Bacteria

Biofilms are surface-associated microbial communities known for their increased resistance to antimicrobials and host factors. This resistance introduces a critical clinical challenge, particularly in cases associated with implants increasing the predisposition for bacterial infections. Preventing such infections requires the development of novel antimicrobials or compounds that enhance bactericidal effect of currently available antibiotics. We have synthesized and characterized twelve novel silver(I) cyanoximates designated as Ag(ACO), Ag(BCO), Ag(CCO), Ag(ECO), Ag(PiCO), Ag(PICO) (yellow and red polymorphs), Ag(BIHCO), Ag(BIMCO), Ag(BOCO), Ag(BTCO), Ag(MCO) and Ag(PiPCO). The compounds exhibit a remarkable resistance to high intensity visible light, UV radiation and heat and have poor solubility in water. All these compounds can be well incorporated into the light-curable acrylate polymeric composites that are currently used as dental fillers or adhesives of indwelling medical devices. A range of dry weight % from 0.5 to 5.0 of the compounds was tested in this study. To study the potential of these compounds in preventing planktonic and biofilm growth of bacteria, we selected two human pathogens (Gram-negative Pseudomonas aeruginosa and Gram-positive Staphylococcus aureus) and Gram-positive environmental isolate Bacillus aryabhattai. Both planktonic and biofilm growth was abolished completely in the presence of 0.5% to 5% of the compounds. The most efficient inhibition was shown by Ag(PiCO), Ag(BIHCO) and Ag(BTCO). The inhibition of biofilm growth by Ag(PiCO)-yellow was confirmed by scanning electron microscopy (SEM). Application of Ag(BTCO) and Ag(PiCO)-red in combination with tobramycin, the antibiotic commonly used to treat P. aeruginosa infections, showed a significant synergistic effect. Finally, the inhibitory effect lasted for at least 120 h in P. aeruginosa and 36 h in S. aureus and B. aryabhattai. Overall, several silver(I) cyanoximates complexes efficiently prevent biofilm development of both Gram-negative and Gram-positive bacteria and present a particularly significant potential for applications against P. aeruginosa infections.

Anodized Aluminum with Nanoholes Impregnated with Quaternary Ammonium Compounds Can Kill Pathogenic Bacteria within Seconds of Contact

Bacterial contamination of surfaces results in the spread of pathogens in public spaces such as hospitals and public transport. The development of antibacterial surfaces that rapidly kill bacteria is therefore highly desirable. Here, we investigate the antibacterial efficacy of a novel anodized aluminum surface featuring nanoholes impregnated with quaternary ammonium compounds, referred to as A3S. The antimicrobial activity of A3S was assessed using both Gram-positive and Gram-negative bacteria in a novel assay which simulates pathogen transfer from a contaminated "finger" to a clean finger in a real-world scenario. Enumeration of colony-forming units shows that the number of viable bacteria on the second "finger" contacting A3S is significantly reduced compared to a control surface. Furthermore, bacterial contact with the A3S material results in compromised cell membranes in less than 1 min, and a kill zone assay shows that an exposure time as short as 5 s is sufficient to kill pathogenic bacteria. The rapid antimicrobial action of A3S was particularly evident against Gram-positive bacteria, that account for more than 70% of nosocomial infections. Taken together, these findings demonstrate that A3S is a promising candidate for the fabrication of antibacterial surfaces that can be used in a wide range of clinical and commercial applications to stop the spread of harmful bacteria.

Nitric oxide releasing vascular catheters for eradicating bacterial infection

The interaction of blood proteins with an implant surface is not only a fundamental phenomenon but is also key to several important medical complications. Plasma proteins binding on the surface of intravascular catheters can promote bacterial adhesion leading to the risk of local and systemic complications such as catheter-related blood infections (CRBIs). The incidences of CRBIs in the United States amount to more than 250,000 cases/year with an attributable mortality of up to 35% and an annual healthcare expenditure of $2.3 billion approximately. This demands the development of truly nonthrombogenic and antimicrobial catheters. In the present study, catheters were fabricated by incorporating a nitric oxide (NO) donor molecule, S-nitroso-N-acetyl-penicillamine (SNAP) in a hydrophobic medical grade polymer, Elasteon-E2As. NO offers antithrombotic and antibacterial attributes without promoting drug resistance and cytotoxicity. E2As-SNAP catheters were first coated with fibrinogen, a blood plasma protein plays a key role in clot formation and eventual bacterial adhesion to the implant surface. The suitability of the catheters for biomedical applications was tested in vitro for contact angle, NO release kinetics, inhibition of bacteria, and absence of cytotoxicity toward mammalian cells. The highly hydrophobic catheters released NO in the physiological range that inhibited >99% bacterial viability on fibrinogen-coated catheters in a 24 h study. No toxic response of E2As-SNAP catheters leachate was observed using a standard cytotoxicity assay with mouse fibroblast cells. Overall, the results showed that the E2As-SNAP catheters can inhibit viable bacteria even in the presence of blood proteins without causing a cytotoxic response. The fundamentals of this study are applicable to other blood-contacting medical devices as well. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 2849-2857, 2018.

Heparin versus 0.9% sodium chloride locking for prevention of occlusion in central venous catheters in adults

BACKGROUND

Intermittent locking of central venous catheters (CVCs) is undertaken to help maintain their patency. There are systematic variations in care: some practitioners use heparin (at different concentrations), whilst others use 0.9% NaCl (normal saline). This review looks at the effectiveness and safety of intermittent locking with heparin compared to 0.9% NaCl to see if the evidence establishes whether one is better than the other. This work is an update of a review first published in 2014.

OBJECTIVES

To assess the effectiveness and safety of intermittent locking of CVCs with heparin versus normal saline (NS) in adults to prevent occlusion.

SEARCH METHODS

The Cochrane Vascular Information Specialist (CIS) searched the Specialised Register (last searched 11 June 2018) and the Cochrane Central Register of Controlled Trials (CENTRAL; 2018, Issue 5). Searches were also carried out in MEDLINE, Embase, CINAHL, and clinical trials databases (11 June 2018).

SELECTION CRITERIA

We included randomised controlled trials in adults ≥ 18 years of age with a CVC that compared intermittent locking with heparin at any concentration versus NS. We applied no restriction on language.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials, assessed quality, and extracted data. We contacted trial authors to retrieve additional information, when necessary. We carried out statistical analysis using Review Manager 5 and assessed the overall quality of the evidence supporting assessed outcomes using GRADE. We carried out prespecified subgroup analysis.

MAIN RESULTS

We identified five new studies for this update (six prior studies were included in the original review), bringing the number of eligible studies to 11, with a total of 2392 participants. We noted differences in methods used by the included studies and variation in heparin concentrations (10 to 5000 IU/mL), time to follow-up (1 to 251.8 days), and the unit of analysis used (participant, catheter, line access).Combined results from these studies showed fewer occlusions with heparin than with NS (risk ratio (RR) 0.70, 95% confidence interval (CI) 0.51 to 0.95; P = 0.02; 1672 participants; 1025 catheters from 10 studies; I² = 14%) and provided very low-quality evidence.We carried out subgroup analysis by unit of analysis (testing for subgroup differences (P = 0.23; I² = 30.3%). When the unit of analysis was the participant, results show no clear differences in all occlusions between heparin and NS (RR 0.79, 95% CI 0.58 to 1.08; P = 0.15; 1672 participants; seven studies). Subgroup analysis using the catheter as the unit of analysis shows fewer occlusions with heparin use (RR 0.53, 95% CI 0.29 to 0.95; P = 0.03; 1025 catheters; three studies). When the unit of analysis was line access, results show no clear differences in occlusions between heparin and NS (RR 1.08, 95% CI 0.84 to 1.40; 770 line accesses; one study).We found no clear differences in the duration of catheter patency (mean difference (MD) 0.44 days, 95% CI -0.10 to 0.99; P = 0.11; 1036 participants; 752 catheters; six studies; low-quality evidence).We found no clear evidence of a difference in the following: CVC-related sepsis (RR 0.74, 95% CI 0.03 to 19.54; P = 0.86; 1097 participants; two studies; low-quality evidence); mortality (RR 0.76, 95% CI 0.44 to 1.31; P = 0.33; 1100 participants; three studies; low-quality evidence); haemorrhage at any site (RR 1.32, 95% CI 0.57 to 3.07; P = 0.52; 1245 participants; four studies; moderate-quality evidence); or heparin-induced thrombocytopaenia (RR 0.21, 95% CI 0.01 to 4.27; P = 0.31; 443 participants; three studies; low-quality evidence).The main reasons for downgrading the quality of evidence were unclear allocation concealment, imprecision, and suspicion of publication bias.

AUTHORS' CONCLUSIONS

Given the very low quality of the evidence, we are uncertain whether intermittent locking with heparin results in fewer occlusions than intermittent locking with NS. Low-quality evidence suggests that heparin may have little or no effect on catheter patency. Although we found no evidence of differences in safety (sepsis, mortality, or haemorrhage), the combined trials are not powered to detect rare adverse events such as heparin-induced thrombocytopaenia.

Effectiveness of antimicrobial-coated central venous catheters for preventing catheter-related blood-stream infections with the implementation of bundles: a systematic review and network meta-analysis

Background

Catheter-related blood-stream infections (CRBSIs) are the most common complication when using central venous catheters (CVCs). Whether coating CVCs under bundles could further reduce the incidence of CRBSIs is unclear. We aimed to assess the effectiveness of implementing the use of bundles with antimicrobial-coated CVCs for preventing catheter-related blood-stream infections.

Methods

In this systematic review and network meta-analyses, we searched the Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library in addition to the EMBASE, MEDLINE, CINAHL, and Web of Science databases for studies published before July 2017. The primary outcome was the rate of CRBSIs per 1000 catheter-days, and the secondary outcome was the incidence of catheter colonization.

Results

Twenty-three studies revealed significant differences in the rate of CRBSIs per 1000 catheter-days between antimicrobial-impregnated and standard CVCs (RR 0.70, 95% CI 0.53–0.91, p = 0.008). Thirty-three trials were included containing 10,464 patients who received one of four types of CVCs. Compared with a standard catheter, chlorhexidine/silver sulfadiazine- and antibiotic-coated catheters were associated with lower numbers of CRBSIs per 1000 catheter-days (ORs and 95% CrIs: 0.64 (0.40–0.955) and 0.53 (0.25–0.95), respectively) and a lower incidence of catheter colonization (ORs and 95% CrIs: 0.44 (0.34–0.56) and 0.30 (0.20–0.46), respectively).

Conclusions

Outcomes are superior for catheters impregnated with chlorhexidine/silver sulfadiazine or other antibiotics than for standard catheters in preventing CRBSIs and catheter colonization under bundles. Compared with silver ion-impregnated CVCs, chlorhexidine/silver sulfadiazine antiseptic catheters resulted in fewer cases of microbial colonization of the catheter but did not reduce CRBSIs.

Electronic supplementary material

The online version of this article (10.1186/s13613-018-0416-4) contains supplementary material, which is available to authorized users.

Antibiofilm Peptides and Peptidomimetics with Focus on Surface Immobilization

Bacterial biofilms pose a major threat to public health, as they are associated with at least two thirds of all infections. They are highly resilient and render conventional antibiotics inefficient. As a part of the innate immune system, antimicrobial peptides have drawn attention within the last decades, as some of them are able to eradicate biofilms at sub-minimum inhibitory concentration (MIC) levels. However, peptides possess a number of disadvantages, such as susceptibility to proteolytic degradation, pH and/or salinity-dependent activity and loss of activity due to binding to serum proteins. Hence, proteolytically stable peptidomimetics were designed to overcome these drawbacks. This paper summarizes the current peptide and peptidomimetic strategies for combating bacteria-associated biofilm infections, both in respect to soluble and surface-functionalized solutions.

Methicillin-resistant Staphylococcus aureus bacteremia among liver transplant recipients: epidemiology and associated risk factors for morbidity and mortality

Bacteremia due to Staphylococcus aureus, especially methicillin-resistant S. aureus (MRSA), complicates the clinical course of liver transplantation and is associated with high morbidity and mortality. Intravascular catheters had been reported to be the most frequent source of MRSA bacteremia. Among bacteremic liver recipients, 26.3%-100% of S. aureus were MRSA. Previous studies identified pre-transplant and post-transplant acquired S. aureus carriage, greater severity of liver disease, hepatocellular carcinoma and infection with immuno-modulatory viruses as predictors of S. aureus bacteremia in liver recipients. MRSA bacteremia accompanied by pneumonia and abdominal infections was related to mortality. Vancomycin, as well as daptomycin, is a first-line antibiotic for MRSA bacteremia. The purpose of this review is to better understand the characteristics of MRSA bacteremia by summarizing the epidemiology and antimicrobial resistance of S. aureus, the primary source, and related risk factors for morbidity and mortality of MRSA bacteremia. We have also explored the diagnostic, therapeutic and preventive measures for MRSA bacteremia to improve the outcomes of liver recipients.

Epidermal necrolysis French national diagnosis and care protocol (PNDS; protocole national de diagnostic et de soins)

Epidermal necrolysis (EN) encompasses Stevens-Johnson syndrome (SJS, < 10% of the skin affected), Lyell syndrome (toxic epidermal necrolysis, TEN, with ≥30% of the skin affected) and an overlap syndrome (10 to 29% of the skin affected). These rare diseases are caused, in 85% of cases, by pharmacological treatments, with symptoms occurring 4 to 28 days after treatment initiation. Mortality is 20 to 25% during the acute phase, and almost all patients display disabling sequelae (mostly ocular impairment and psychological distress).

The objective of this French national diagnosis and care protocol (protocole national de diagnostic et de soins; PNDS), based on a critical literature review and on a multidisciplinary expert consensus, is to provide health professionals with an explanation of the optimal management and care of patients with EN. This PNDS, written by the French National Reference Center for Toxic Bullous Dermatoses was updated in 2017 (https://www.has-sante.fr/portail/jcms/c_1012735/fr/necrolyse-epidermique-syndromes-de-stevens-johnson-et-de-lyell). The cornerstone of the management of these patients during the acute phase is an immediate withdrawal of the responsible drug, patient management in a dermatology department, intensive care or burn units used to dealing with this disease, supportive care and close monitoring, the prevention and treatment of infections, and a multidisciplinary approach to sequelae. Based on published data, it is not currently possible to recommend any specific immunomodulatory treatment. Only the culprit drug and chemically similar molecules must be lifelong contraindicated.

Shaw CM, Shah S, Kapoor BS, Cain TR, Caplin DM, Farsad K, Knuttinen MG, Lee MH, McBride JJ, Minocha J, Robilotti EV, Rochon PJ, Strax R, Teo EYL, Lorenz JM. ACR Appropriateness Criteria® Radiologic Management of Central Venous Access

Obtaining central venous access is one of the most commonly performed procedures in hospital settings. Multiple devices such as peripherally inserted central venous catheters, tunneled central venous catheters (eg, Hohn catheter, Hickman catheter, C. R. Bard, Inc, Salt Lake City UT), and implantable ports are available for this purpose. The device selected for central venous access depends on the clinical indication, duration of the treatment, and associated comorbidities. It is important for health care providers to familiarize themselves with the types of central venous catheters available, including information about their indications, contraindications, and potential complications, especially the management of catheters in the setting of catheter-related bloodstream infections. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

In vitro methods for the evaluation of antimicrobial surface designs

Bacterial adhesion and subsequent biofilm formation on biomedical implants and devices are a major cause of their failure. As systemic antibiotic treatment is often ineffective, there is an urgent need for antimicrobial biomaterials and coatings. The term "antimicrobial" can encompass different mechanisms of action (here termed "antimicrobial surface designs"), such as antimicrobial-releasing, contact-killing or non-adhesivity. Biomaterials equipped with antimicrobial surface designs based on different mechanisms of action require different in vitro evaluation methods. Available industrial standard evaluation tests do not address the specific mechanisms of different antimicrobial surface designs and have therefore been modified over the past years, adding to the myriad of methods available in the literature to evaluate antimicrobial surface designs. The aim of this review is to categorize fourteen presently available methods including industrial standard tests for the in vitro evaluation of antimicrobial surface designs according to their suitability with respect to their antimicrobial mechanism of action. There is no single method or industrial test that allows to distinguish antimicrobial designs according to all three mechanisms identified here. However, critical consideration of each method clearly relates the different methods to a specific mechanism of antimicrobial action. It is anticipated that use of the provided table with the fourteen methods will avoid the use of wrong methods for evaluating new antimicrobial designs and therewith facilitate translation of novel antimicrobial biomaterials and coatings to clinical use. The need for more and better updated industrial standard tests is emphasized.

STATEMENT OF SIGNIFICANCE

European COST-action TD1305, IPROMEDAI aims to provide better understanding of mechanisms of antimicrobial surface designs of biomaterial implants and devices. Current industrial evaluation standard tests do not sufficiently account for different, advanced antimicrobial surface designs, yet are urgently needed to obtain convincing in vitro data for approval of animal experiments and clinical trials. This review aims to provide an innovative and clear guide to choose appropriate evaluation methods for three distinctly different mechanisms of antimicrobial design: (1) antimicrobial-releasing, (2) contact-killing and (3) non-adhesivity. Use of antimicrobial evaluation methods and definition of industrial standard tests, tailored toward the antimicrobial mechanism of the design, as identified here, fulfill a missing link in the translation of novel antimicrobial surface designs to clinical use.

Urokinase Lock or Flush Solution for Prevention of Bloodstream Infections Associated with Central Venous Catheters for Chemotherapy: A Meta-Analysis of Prospective Randomized Trials

Background

Intravascular devices (IVDs) carry significant risk of device-associated bloodstream infection (BSI). Catheter thrombosis increases the likelihood of microbial colonization of the catheter and BSI. Urokinase has been studied for the prevention of BSI associated with IVDs. We undertook a systematic review to determine the efficacy of urokinase-heparin lock or flush solution compared with heparin alone in preventing IVD-associated BSI.

Methods

Computerized databases were searched for relevant publications in English from January 1966 to 1 January 2007. We identified randomized controlled trials comparing a urokinase-heparin lock or flush solution with heparin alone for prevention of BSI associated with long-term IVDs. Summary effect sizes were calculated with assessment of heterogeneity.

Results

Five randomized, controlled trials involving a total of 991 patients being treated with IVDs met the inclusion criteria; all five studies were conducted among patients with cancer; three of these studies were undertaken in children and two in adults. The summary risk ratio with a urokinase-heparin lock solution for IVD-associated BSI was 0.77 (95% confidence interval [CI], 0.60–0.98; p=0.01). Results of the test for heterogeneity were not statistically significant (p=0.53).

Conclusions

Use of a urokinase lock solution in high-risk patient populations being treated with long-term central IVDs may reduce the risk of BSI. However, there are few randomized trials and methodologic limitations of these preclude more robust recommendations regarding the use of urokinase to prevent BSI. Further adequately powered studies should seek to evaluate the efficacy of urokinase and optimize dosage and instillation regimen.

Intravascular Catheters and Biofilm Control

Intravascular catheters are the most common cause of nosocomially acquired bloodstream infections. Bacteria found adhering to the intraluminal surfaces of catheters are the principal source and cause of these infections. Adherent bacteria overtime are known to form multicellular communities which become encased within a three dimensional matrix of extracellular polymeric material known as biofilms, which are thought to be responsible for persistent infections. Consequently, a number of technologies have been developed to help prevent and control biofilms in intravascular catheters. One such approach involves impregnating catheter material with antimicrobial agents. Unfortunately these methods are not universally effective in preventing catheter-related biofilm infections. Technologies that utilise antimicrobials, as catheter locks have been shown to have more potential for preventing biofilm formation and reducing the incidences of catheter related bloodstream infections (CRBSI). This article discusses the significance of biofilms in intravascular catheters and determines whether the treatments available today are proving to be effective for controlling biofilms and draws attention to future avenues which are being investigated to control biofilms and therefore CRBSI.

Antimicrobially Impregnated Catheters: An Overview of Randomized Controlled Trials

In order to acquire an overview of the effectiveness of antimicrobially impregnated catheters on the prevention of catheter related bloodstream infections (CRI), we conducted a systematic review concentrating on randomized controlled trials (RCTs). The analysis end point was CRI; therefore, studies focussing only on catheter colonization were excluded. We did not consider abstracts for analysis. We identified 24 RCTs investigating the effectiveness of antimicrobially impregnated catheters. In addition, we discovered five meta-analyses and four studies investigating cost effectiveness. For the majority of antimicrobially impregnated catheter types only a few studies were available, and not enough to draw conclusions. Therefore, despite a relatively large number of RCTs available, the routine use of antimicrobially impregnated catheters as a measure for CRI prevention remains controversial, with a need for more high quality studies.

Efficacy and safety of peripherally inserted central venous catheters in acute cardiac care management

PURPOSE

Patients admitted to cardiac intensive care unit need administration of drugs intravenously often in concomitance of therapeutic techniques such as non-invasive ventilation, continuous renal replacement therapy and intra-aortic balloon counterpulsation. Therefore, the insertion of central venous catheters provides a reliable access for delivering medications, laboratory testing and hemodynamic monitoring, but it is associated with the risk of important complications. In our study, we tested the efficacy and safety of peripherally inserted central catheters to manage cardiac intensive care.

METHODS

All patients admitted to cardiac intensive care unit with indication for elective central venous access were checked by venous arm ultrasound for peripherally inserted central catheter's implantation. Peripherally inserted central catheters were inserted by ultrasound-guided puncture. After 7 days from the catheter's placement and at the removal, vascular ultrasound examination was performed searching signs of upper extremity deep venous thrombosis. In case of sepsis, blood cultures peripherally from the catheter and direct culture of the tip of the catheter were done to establish a catheter-related blood stream infection.

RESULTS

In our cardiac intensive care unit, 137 peripherally inserted central catheters were placed: 80.3% of patients eligible for a peripherally inserted central catheter were implanted. The rate of symptomatic catheter-related peripheral venous thrombosis was 1.4%. Catheter-related blood stream infection was diagnosed in one patient (0.7%; 5.7 × 1000 peripherally inserted central catheter days). All peripherally inserted central catheters were inserted successfully without other major complications.

CONCLUSIONS

In patients admitted to cardiac intensive care unit, peripherally inserted central catheters' insertion was feasible in a high percentage of patients and was associated with low infective complications and clinical thrombosis rate.

Modern Strategies in the Prevention of Implant-Associated Infections

The application of medical devices either for temporary or permanent use has become an indispensible part of almost all fields of medicine. However, foreign bodies are associated with a substantial risk of bacterial and fungal infections. Implant-associated infections significantly contribute to the still increasing problem of nosocomial infections.

To reduce the incidence of such infections, specific guidelines providing evidence-based recommendations and comprising both technological and nontechnological strategies for prevention have been established. Strict adherence to hygienic rules during insertion or implantation of the device are aspects of particular importance. Besides such basic and indispensable aspects, the development of new materials which could withstand microbial adherence and colonization has become a major topic in recent years. Modification of surface by primarily physico-chemical methods may lead to a change in specific and unspecific interactions with microorganisms and, thus, to a reduction in microbial adherence. Medical devices made out of a material that would be ideally antiadhesive or at least colonization-resistant would be the most suitable candidates to avoid colonization and subsequent infection. However, it appears impossible to create a surface with an absolute “zero”-adherence due to thermodynamical reasons and due to the fact that a modified material surface is in vivo rapidly covered by plasma and connective tissue proteins. Therefore, another concept for the prevention of implant-associated infections involves the impregnation of devices with various antimicrobial substances such as antibiotics, antiseptics, and/or metals.

In fact, already commercially available materials for clinical use such as antimicrobial catheters have been introduced, in part with considerable impact on subsequent infections. However, future studies are warranted to translate the knowledge on the pathogenesis of device-associated infections into applicable prevention strategies.

Anti-fouling strategies for central venous catheters

Central venous catheters (CVCs) are ubiquitous in the healthcare industry and carry two common complications, catheter related infections and occlusion, particularly by thrombus. Catheter-related bloodstream infections (CRBSI) are an important cause of nosocomial infections that increase patient morbidity, mortality, and hospital cost. Innovative design strategies for intravenous catheters can help reduce these preventable infections. Antimicrobial coatings can play a major role in preventing disease. These coatings can be divided into two major categories: drug eluting and non-drug eluting. Much of these catheter designs are targeted at preventing the formation of microbial biofilms that make treatment of CRBSI nearly impossible without removal of the intravenous device. Exciting developments in catheter impregnation with antibiotics as well as nanoscale surface design promise innovative changes in the way that physicians manage intravenous catheters. Occlusion of a catheter renders the catheter unusable and is often treated by tissue plasminogen activator administration or replacement of the line. Prevention of this complication requires a thorough understanding of the mechanisms of platelet aggregation, signaling and cross-linking. This article will look at the advances in biomaterial design specifically drug eluting, non-drug eluting, lubricious coatings and micropatterning as well as some of the characteristics of each as they relate to CVCs.

Anti-Candida activity of antimicrobial impregnated central venous catheters

Background

Whenever the rate of central line-associated bloodstream infections (CLABSIs) remains high even after the implementation of preventive strategies, the use of chlorhexidine/silver sulfadiazine (CSS) or minocycline/rifampin (MR)-impregnated central venous catheters (CVCs) is currently recommended. Nevertheless, the efficacy of such CVCs against Candida albicans and other emerging non-albicans spp. has been insufficiently studied. This study aims to compare the activity of CSS and MR-impregnated CVCs against the yeasts most frequently isolated from CLABSIs.

Methods

For biofilm formation assays, type strains and clinical isolates of C. albicans, C. glabrata and C. parapsilosis sensu stricto were used. Segments of standard polyurethane, MR and second-generation CSS-CVCs were tested. The biofilm metabolic activity was measured by a semi-quantitative XTT reduction assay.

Results

CSS catheter segments significantly reduced the biofilm metabolic activity by all tested Candida spp., with inhibition ranging from 60% to 100%. The MR catheter segments promoted C. albicans and C. parapsilosis biofilm formation and exhibited an inconspicuous effect against C. glabrata.

Conclusions

Among the recommended antimicrobial CVCs, CSS-CVCs proved to be superior in the inhibition of biofilm formation by the most frequent yeasts causing CLABSIs. Data from this in vitro study may suggest that patients at high risk for invasive candidosis could benefit from the use of CSS-CVCs.