Prevention of Vascular Catheter-Related Bloodstream Infections

Development of best evidence-based practice protocols for central venous catheter placement and maintenance to reduce CLABSI

Although evidence-based interventions can reduce the incidence of central line-associated bloodstream infection (CLABSI), there is a large gap between evidence-based interventions and the actual practice of central venous catheter (CVC) care. Evidence-based interventions are needed to reduce the incidence of CLABSI in intensive care units (ICU) in China. Professional association, guidelines, and database websites were searched for data relevant to CLABSI in the adult ICUs from inception to February 2020. Checklists were developed for both CVC placement and maintenance. Based on the Integrated Promoting Action on Research Implementation in Health Services framework, a questionnaire collected the cognition and practice of ICU nursing and medical staff on the CLABSI evidence-based prevention guidelines. From January 2018 to December 2021, ICU CLABSI rates were collected monthly. Ten clinical guidelines were included after the screening and evaluation process and used to develop the best evidence-based protocols for CVC placement and maintenance. The CLABSI rates in 2018, 2019, and 2020 were 2.98‰ (9/3021), 1.83‰ (6/3276), and 1.69‰ (4/2364), respectively. Notably, the CLABSI rate in 2021 was 0.38‰ (1/2607). In other words, the ICU CLABSI rate decreased from 1.69‰ to 0.38‰ after implementation of the new protocols. Additionally, our data suggested that the use of ultrasound-guidance for catheter insertion, chlorhexidine body wash, and the use of a checklist for CVC placement and maintenance were important measures for reducing the CLABSI rate. The evidence-based processes developed for CVC placement and maintenance were effective at reducing the CLABSI rate in the ICU.

Current Insights Regarding Intestinal Failure-Associated Liver Disease (IFALD): A Narrative Review

Intestinal failure-associated liver disease (IFALD) is a spectrum of liver disease including cholestasis, biliary cirrhosis, steatohepatitis, and gallbladder disease in patients with intestinal failure (IF). The prevalence of IFALD varies considerably, with ranges of 40-60% in the pediatric population, up to 85% in neonates, and between 15-40% in the adult population. IFALD has a complex and multifactorial etiology; the risk factors can be parenteral nutrition-related or patient-related. Because of this, the approach to managing IFALD is multidisciplinary and tailored to each patient based on the etiology. This review summarizes the current knowledge on the etiology and pathophysiology of IFALD and examines the latest evidence regarding preventative measures, diagnostic approaches, and treatment strategies for IFALD and its associated complications.

Integrating structured and unstructured data for timely prediction of bloodstream infection among children

BACKGROUND

Hospitalized children with central venous lines (CVLs) are at higher risk of hospital-acquired infections. Information in electronic health records (EHRs) can be employed in training deep learning models to predict the onset of these infections. We incorporated clinical notes in addition to structured EHR data to predict serious bloodstream infections, defined as positive blood culture followed by at least 4 days of new antimicrobial agent administration, among hospitalized children with CVLs.

METHODS

Structured EHR information and clinical notes were extracted for a retrospective cohort including all hospitalized patients with CVLs at a single tertiary care pediatric health system from 2013 to 2018. Deep learning models were trained to determine the added benefit of incorporating the information embedded in clinical notes in predicting serious bloodstream infection.

RESULTS

A total of 24,351 patient encounters met inclusion criteria. The best-performing model restricted to structured EHR data had a specificity of 0.951 and positive predictive value (PPV) of 0.056 when the sensitivity was set to 0.85. The addition of contextualized word embeddings improved the specificity to 0.981 and PPV to 0.113.

CONCLUSIONS

Integrating clinical notes with structured EHR data improved the prediction of serious bloodstream infections among pediatric patients with CVLs.

IMPACT

Developed an advanced infection prediction model in pediatrics that integrates the structured and unstructured EHRs. Extracted information from clinical notes to do timely prediction in a clinical setting. Developed a deep learning model framework that can be employed in predicting rare events in a complex and dynamic environment.

Deep Learning Model to Predict Serious Infection Among Children With Central Venous Lines

Objective: Predict the onset of presumed serious infection, defined as a positive blood culture drawn and new antibiotic course of at least 4 days (PSI*), among pediatric patients with Central Venous Lines (CVLs). Design: Retrospective cohort study. Setting: Single academic children's hospital. Patients: All hospital encounters from January 2013 to December 2018, excluding the ones without a CVL or with a length-of-stay shorter than 24 h. Measurements and Main Results: Clinical features including demographics, laboratory results, vital signs, characteristics of the CVLs and medications used were extracted retrospectively from electronic medical records. Data were aggregated across all hospitals within a single pediatric health system and used to train a deep learning model to predict the occurrence of PSI* during the next 48 h of hospitalization. The proposed model prediction was compared to prediction of PSI* by a marker of illness severity (PELOD-2). The baseline prevalence of line infections was 0.34% over all segmented 48-h time windows. Events were identified among cases using onset time. All data from admission till the onset was used for cases and among controls we used all data from admission till discharge. The benchmarks were aggregated over all 48 h time windows [N=748,380 associated with 27,137 patient encounters]. The model achieved an area under the receiver operating characteristic curve of 0.993 (95% CI = [0.990, 0.996]), the enriched positive predictive value (PPV) was 23 times greater than the base prevalence. Conversely, prediction by PELOD-2 achieved a lower PPV of 1.5% [0.9%, 2.1%] which was 5 times the baseline prevalence. Conclusion: A deep learning model that employs common clinical features in the electronic health record can help predict the onset of CLABSI in hospitalized children with central venous line 48 hours prior to the time of specimen collection.

New insights into intestinal failure-associated liver disease in adults: A comprehensive review of the literature

Intestinal failure-associated liver disease (IFALD) remains one of the most common and serious complications of parenteral nutrition (PN), causing a wide spectrum of hepatic manifestations from steatosis and mild cholestasis to portal hypertension and end-stage liver failure. The prevalence of IFALD depends on the diagnostic criteria and ranges from 4.3% to 65%. Moreover, many factors are shown to contribute to its development, including nutrient deficiencies, toxicity of PN, infections, and alterations of bile acid metabolism and gut microbiota. Prevention and management of IFALD aim at ameliorating or eliminating the risk factors associated with IFALD. The use of PN formulations with a lower ratio omega-6-to-omega-3 polyunsaturated fatty acids, cycle PN, optimization of enteral stimulation and prevention and early treatment of infections constitute the main therapeutic targets. However, failure of improvement and severe IFALD with end-stage liver failure should be considered as the indications of intestinal transplantation. The aim of this review is to provide an update of the epidemiology, pathophysiology, and diagnosis of IFALD in the adult population as well as to present a clinical approach of the therapeutic strategies of IFALD and present novel therapeutic targets.

Molecular tracking of pathogens in central venous catheter

BACKGROUND

Central venous catheter-related bloodstream infection is an important adverse event in health care. Molecular methods are not yet substitutive of microbiological in the detection of the pathogens responsible for the infection, but they can help in the epidemiological characterization.

AIM

To detect bacteria by polymerase chain reaction, from material extracted from the tip of central catheters of patients suspected of infection at the intensive care unit.

METHODS

Catheters (n = 34) of patients suspected of central venous catheter-related infection were analyzed by polymerase chain reaction. The findings were compared with culture of catheter tip and blood cultures performed by the hospital.

FINDINGS

The prevalence of bacteria was Staphylococcus aureus (50%), Enterococcus faecalis (41.2%), Klebsiella pneumoniae (32.4), Pseudomonas aeruginosa (20.6%), Acinetobacter baumannii (38.2%), Escherichia coli (2.9%), and Enterobacter cloacae (0%). No blood culture showed bacterial growth, the culture of catheter tip revealed bacteria in 21 (61.8%) and the polymerase chain reaction had positivity in 31 (91.2%) of the catheters. The mean central venous catheter time was 11 days, and the jugular vein was the site of insertion.

CONCLUSION

The molecular method identified more bacteria than microbiological methods and revealed colonization of the catheters. The most commonly found bacteria are in the environment and in the microbiota of the skin, which suggests contamination by the hands of health professionals and points out the need for more efforts in preventive strategies.

The Impact of Engineered Silver Nanomaterials on the Immune System

Over the last decades there has been a tremendous volume of research efforts focused on engineering silver-based (nano)materials. The interest in silver has been mostly driven by the element capacity to kill pathogenic bacteria. In this context, the main area of application has been medical devices that are at significant risk of becoming colonized by bacteria and subsequently infected. However, silver nanomaterials have been incorporated in a number of other commercial products which may or may not benefit from antibacterial protection. The rapid expansion of such products raises important questions about a possible adverse influence on human health. This review focuses on examining currently available literature and summarizing the current state of knowledge of the impact of silver (nano)materials on the immune system. The review also looks at various surface modification strategies used to generate silver-based nanomaterials and the immunomodulatory potential of these materials. It also highlights the immune response triggered by various silver-coated implantable devices and provides guidance and perspective towards engineering silver nanomaterials for modulating immunological consequences.

Risk stratification for early bacteremia after living donor liver transplantation: a retrospective observational cohort study

BACKGROUND

This study investigated perioperative clinical risk factors for early post-transplant bacteremia in patients undergoing living donor liver transplantation (LDLT). Additionally, postoperative outcomes were compared between patients with and without early post-transplant bacteremia.

METHODS

Clinical data of 610 adult patients who underwent elective LDLT between January 2009 and December 2018 at Seoul St. Mary's Hospital were retrospectively collected. The exclusion criteria included overt signs of infection within 1 month before surgery. A total of 596 adult patients were enrolled in this study. Based on the occurrence of a systemic bacterial infection after surgery, patients were classified into non-infected and infected groups.

RESULTS

The incidence of bacteremia at 1 month after LDLT was 9.7% (57 patients) and Enterococcus faecium (31.6%) was the most commonly cultured bacterium in the blood samples. Univariate analysis showed that preoperative psoas muscle index (PMI), model for end-stage disease score, utility of continuous renal replacement therapy (CRRT), ascites, C-reactive protein to albumin ratio, neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio, and sodium level, as well as intraoperative post-reperfusion syndrome, mean central venous pressure, requirement for packed red blood cells and fresh frozen plasma, hourly fluid infusion and urine output, and short-term postoperative early allograft dysfunction (EAD) were associated with the risk of early post-transplant bacteremia. Multivariate analysis revealed that PMI, the CRRT requirement, the NLR, and EAD were independently associated with the risk of early post-transplant bacteremia (area under the curve: 0.707; 95% confidence interval: 0.667-0.745; p < 0.001). The overall survival rate was better in the non-infected patient group. Among patients with bacteremia, anti-bacterial treatment was unable to resolve infection in 34 patients, resulting in an increased risk of patient mortality. Among the factors included in the model, EAD was significantly correlated with non-resolving infection.

CONCLUSIONS

We propose a prognostic model to identify patients at high risk for a bloodstream bacterial infection; furthermore, our findings support the notion that skeletal muscle depletion, CRRT requirement, systemic inflammatory response, and delayed liver graft function are associated with a pathogenic vulnerability in cirrhotic patients who undergo LDLT.

Anti-Biofilm Effects of Synthetic Antimicrobial Peptides Against Drug-Resistant Pseudomonas aeruginosa and Staphylococcus aureus Planktonic Cells and Biofilm

Biofilm-associated infections are difficult to manage or treat as biofilms or biofilm-embedded bacteria are difficult to eradicate. Antimicrobial peptides have gained increasing attention as a possible alternative to conventional drugs to combat drug-resistant microorganisms because they inhibit the growth of planktonic bacteria by disrupting the cytoplasmic membrane. The current study investigated the effects of synthetic peptides (PS1-2, PS1-5, and PS1-6) and conventional antibiotics on the growth, biofilm formation, and biofilm reduction of drug-resistant Pseudomonas aeruginosa and Staphylococcus aureus. The effects of PS1-2, PS1-5, and PS1-6 were also tested in vivo using a mouse model. All peptides inhibited planktonic cell growth and biofilm formation in a dose-dependent manner. They also reduced preformed biofilm masses by removing the carbohydrates, extracellular DNA, and lipids that comprised extracellular polymeric substances (EPSs) but did not affect proteins. In vivo, PS1-2 showed the greatest efficacy against preformed biofilms with no cytotoxicity. Our findings indicate that the PS1-2 peptide has potential as a next-generation therapeutic drug to overcome multidrug resistance and to regulate inflammatory response in biofilm-associated infections.

Examination of nursing drug administration practices via central venous catheter: An observational study

AIM

To determine the compliance with nursing drug administration procedure steps associated with access to the central venous catheter for bolus infusion in intensive care units.

METHODS

This observational study was conducted with 30 nurses working in an intensive care unit of a university hospital. The drug administrations practiced by nurses via central venous catheter were monitored simultaneously at 12:00 a.m., 02:00 p.m., and 06:00 p.m. by two observers. The data were collected using a data collection form and central venous catheter drug administration procedure steps.

RESULTS

A total of 90 different drug administrations were observed in three different treatment hours from 30 nurses. The interobserver conformity was found to be moderate in two steps (kappa = 0.520-0.627, P = 0.01) and perfect in all other steps (kappa = 0.821-1.000, P = 0.000). According to the drug administration procedure steps via a central venous catheter, all nurses applied the following steps correctly during all treatment hours: drug card control, preparation of treatment materials, checking the patient's identity, and steps of drug treatment administration. The following tasks were frequently performed incorrectly or not at all: hand hygiene (before treatment 87.8%; after treatment 82.2%), scrubbing the three-way stopcock entrance with an alcohol swab (55.6%), waiting for the alcohol to dry (81.1%), and flushing the lumen with a compatible fluid (before treatment 84.4%: after treatment 75.6%).

CONCLUSION

Observation of drug administration procedure steps via central venous catheter according to the treatment hours showed that the nurses performed many incomplete or inaccurate drug administration procedure steps and the mistakes increased toward the evening hours.

Using the agile implementation model to reduce central line-associated bloodstream infections

BACKGROUND

Central line-associated bloodstream infections (CLABSIs) are among the most common hospital-acquired infections and can lead to increased patient morbidity and mortality rates. Implementation of practice guidelines and recommended prevention bundles has historically been suboptimal, suggesting that improvements in implementation methods could further reductions in CLABSI rates. In this article, we describe the agile implementation methodology and present details of how it was successfully used to reduce CLABSI.

METHODS

We conducted an observational study of patients with central line catheters at 2 adult tertiary care hospitals in Indianapolis from January 2015 to June 2017.

RESULTS

The intervention successfully reduced the CLABSI rate from 1.76 infections per 1,000 central line days to 1.24 (rate ratio = 0.70; P = .011). We also observed reductions in the rates of Clostridium difficile and surgical site infections, whereas catheter-associated urinary tract infections remained stable.

CONCLUSIONS

Using the AI model, we were able to successfully implement evidence-based practices to reduce the rate of CLABSIs at our facility.

Assessing patient risk of central line-associated bacteremia via machine learning

BACKGROUND

Central line-associated bloodstream infections (CLABSIs) contribute to increased morbidity, length of hospital stay, and cost. Despite progress in understanding the risk factors, there remains a need to accurately predict the risk of CLABSIs and, in real time, prevent them from occurring.

METHODS

A predictive model was developed using retrospective data from a large academic healthcare system. Models were developed with machine learning via construction of random forests using validated input variables.

RESULTS

Fifteen variables accounted for the most significant effect on CLABSI prediction based on a retrospective study of 70,218 unique patient encounters between January 1, 2013, and May 31, 2016. The area under the receiver operating characteristic curve for the best-performing model was 0.82 in production.

DISCUSSION

This model has multiple applications for resource allocation for CLABSI prevention, including serving as a tool to target patients at highest risk for potentially cost-effective but otherwise time-limited interventions.

CONCLUSIONS

Machine learning can be used to develop accurate models to predict the risk of CLABSI in real time prior to the development of infection.

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.

In vitro assessment of the anti-biofilm activity of ethanol alone and in combination with enoxaparin 60IU

INTRODUCTION

Catheter-related bloodstream infection (C-RBSI) can sometimes be managed without catheter removal by combining systemic therapy with catheter lock therapy. Most antiseptic lock solutions are made up of ethanol combined with an anticoagulant. However, data regarding the anti-biofilm activity of ethanol combined with enoxaparin are scarce. We aimed to assess the efficacy of ethanol at different concentrations combined with enoxaparin 60IU as a lock solution for eradication of the biofilm of different microorganisms.

METHODS

Using a static 96-well plate in vitro model, we tested 30%, 35%, and 40% ethanol alone and combined with 60IU of enoxaparin against 24-h-old biofilm from the following microorganisms: Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis, Escherichia coli, and Candida albicans. Time of exposure was assessed during a 2-h and 24-h regimen. We analysed the percentage reduction in metabolic activity using the XTT assay. We considered therapy to be successful when metabolic activity was reduced by >90%.

RESULTS

In the 2-h regimen, the therapy was successful against all microorganisms at 35% and 40% ethanol without enoxaparin (p<0.001). In the 24-h regimen, the therapy was successful against all microorganisms at all ethanol solutions without enoxaparin (p<0.001). When ethanol was combined with enoxaparin, the therapy was only successful in the 24-h regimen in biofilms of S. epidermidis, C. albicans and E. coli at all concentrations of ethanol assessed.

CONCLUSIONS

Our in vitro model demonstrated that when ethanol is combined with enoxaparin in a lock solution, it negatively affects ethanol anti-biofilm activity after both short and long exposures.

Taurolidine-citrate-heparin lock reduces catheter-related bloodstream infections in intestinal failure patients dependent on home parenteral support: a randomized, placebo-controlled trial

Background: In patients with intestinal failure who are receiving home parenteral support (HPS), catheter-related bloodstream infections (CRBSIs) inflict health impairment and high costs.Objective: This study investigates the efficacy and safety of the antimicrobial catheter lock solution, taurolidine-citrate-heparin, compared with heparin 100 IE/mL on CRBSI occurrence.Design: Forty-one high-risk patients receiving HPS followed in a tertiary HPS unit were randomly assigned in a double-blinded, placebo-controlled trial. External, stratified randomization was performed according to age, sex, and prior CRBSI incidence. The prior CRBSI incidence in the study population was 2.4 episodes/1000 central venous catheter (CVC) days [95% Poisson confidence limits (CLs): 2.12, 2.71 episodes/1000 CVC days]. The maximum treatment period was 2 y or until occurrence of a CRBSI or right-censoring because of CVC removal. The exact permutation tests were used to calculate P values for the log-rank tests.Results: Twenty patients received the taurolidine-citrate-heparin lock and 21 received the heparin lock, with 9622 and 6956 treatment days, respectively. In the taurolidine-citrate-heparin arm, no CRBSIs occurred, whereas 7 CRBSIs occurred in the heparin arm, with an incidence of 1.0/1000 CVC days (95% Poisson CLs: 0.4, 2.07/1000 CVC days; P = 0.005). The CVC removal rates were 0.52/1000 CVC days (95% Poisson CLs: 0.17, 1.21/1000 CVC days) and 1.72/1000 CVC days (95% Poisson CLs: 0.89, 3.0/1000 CVC days) in the taurolidine-citrate-heparin and heparin arm, respectively, tending to prolong CVC survival in the taurolidine arm (P = 0.06). Costs per treatment year were lower in the taurolidine arm (€2348) than in the heparin arm (€6744) owing to fewer admission days related to treating CVC-related complications (P = 0.02).Conclusions: In patients with intestinal failure who are life dependent on HPS, the taurolidine-citrate-heparin catheter lock demonstrates a clinically substantial and cost-beneficial reduction of CRBSI occurrence in a high-risk population compared with heparin. This trial was registered at clinicaltrials.gov as NCT01948245.