Efficacy of intravascular catheter lock solutions containing preservatives in the prevention of microbial colonization

Endocrine-disrupting chemicals: Mainstream recognition of health effects and implications for the practicing internist

Rapidly advancing evidence documents that a broad array of synthetic chemicals found ubiquitously in the environment contribute to disease and disability across the lifespan. Although the early literature focused on early life exposures, endocrine-disrupting chemicals (EDCs) are now understood to contribute substantially to chronic disease in adulthood, especially metabolic, cardiovascular, and reproductive consequences as well as endocrine cancers. The contribution to mortality is substantial, with over 90,000 deaths annually and at least $39 billion/year in lost economic productivity in the United States (US) due to exposure to certain phthalates that are used as plasticizers in food packaging. Importantly, exposures are disproportionately high in low-income and minoritized populations, driving disparities in these conditions. Though non-Hispanic Blacks and Mexican Americans comprise 12.6% and 13.5% of the US population, they bear 16.5% and 14.6% of the disease burden due to EDCs, respectively. Many of these exposures can be modified through safe and simple behavioral changes supported by proactive government action to both limit known hazardous exposures and to proactively screen new industrial chemicals prior to their use. Routine healthcare maintenance should include guidance to reduce EDC exposures, and a recent report by the Institute of Medicine suggests that testing be conducted, particularly in populations heavily exposed to perfluoroalkyl substances-chemicals used in nonstick coatings as well as oil- and water-resistant clothing.

The Pediatrician's Role in Protecting Children from Environmental Hazards

Children suffer disproportionately from disease and disability due to environmental hazards, for reasons rooted in their biology. The contribution is substantial and increasingly recognized, particularly due to ever-increasing awareness of endocrine disruption. Regulatory actions can be traced directly to reductions in toxic exposures, with tangible benefits to society. Deep flaws remain in the policy framework in industrialized countries, failing to offer sufficient protection, but are even more limited in industrializing nations where the majority of chemical production and use will occur by 2030. Evidence-based steps for reducing chemical exposures associated with adverse health outcomes exist and should be incorporated into anticipatory guidance.

Bacteriostatic preserved saline for pain-free periocular injections: review

We review evidence regarding the use of 0.9% benzyl alcohol in 0.9% sodium chloride solution for periocular injections (‘preserved saline’) including botulinum toxin A injections and local anaesthesia. A literature search was undertaken using search terms ‘bacteriostatic saline’, ‘benzyl-alcohol saline’, ‘benzyl alcohol sodium chloride’ and ‘preserved saline’. Bibliographies identified further sources. There have been 62 studies published on the subject of preserved-saline since 1928. Significantly lower injection-associated pain levels for periocular/facial botulinum toxin injections reconstituted with preserved-saline rather than preservative-free saline are reported by 5 studies. Significantly lower injection-associated pain with preserved-saline diluted lidocaine and epinephrine solution for eyelid anaesthesia compared with unmodified or buffered lidocaine with epinephrine, and adequate anaesthesia, was reported by one study. Thirty-one studies have explored preserved-saline for anaesthetic and seven for bacteriostatic properties, with very low infection rates after periocular botulinum toxin injections, and reduced rates of infection in indwelling catheters when preserved saline is used to flush. A meta-analysis concluded that lidocaine-containing solutions are more effective at reducing pain from insertion of intravenous catheters. Patient-perceived pain related to periorbital injections of local anaesthesia is reduced when the anaesthetic is diluted with benzyl alcohol-preserved saline compared with other dilution or buffering options. Pain is similarly reduced for periocular botulinum toxin injections reconstituted with preserved saline compared with unpreserved saline. Benzyl-alcohol preserved-saline is inexpensive but costlier than unpreserved-saline, with minimal reported complications, particularly with periocular administration, and offers the opportunity to improve the patient experience.

Unwitting Accomplices: Endocrine Disruptors Confounding Clinical Care

Burgeoning evidence over the last 25 years has identified myriad synthetic chemicals with the capacity to alter various aspects of hormone synthesis and action. These endocrine-disrupting chemicals (EDCs) have been linked to various diseases, including reproductive disorders, metabolic diseases, and developmental abnormalities, among others. Exposure to EDCs arises from industrial activity, use of personal and home care products, and consumption of contaminated food and water; however, the role of healthcare in exposing individuals to EDCs is grossly underappreciated. Indeed, through the use of medications as well as medical equipment and devices, healthcare providers are unknowing mediators of exposure to EDCs, chemicals that might not only promote disease but that may also antagonize the efficacy of treatments. The ethical implications of provider-dependent exposure are profound. A failure to disclose the endocrine-disrupting properties of medical interventions violates core principles of nonmaleficence, patient autonomy, and justice as well as the practice of informed consent. Furthermore, physicians' lack of knowledge regarding EDCs in medical practice artificially skews risk-benefit calculations that are fundamental to informed medical decision-making. To combat this underappreciated ethical challenge, urgent action is required. Healthcare providers must be educated about endocrine disruption. Known EDCs, defined by endocrinologists, should be clearly labeled on all medical products, and all medication components and devices should be screened for endocrine-disrupting properties. Finally, communication strategies must be devised to empower patients with knowledge about these risks. Providing ethically competent care requires an open acknowledgment of endocrine risks imposed by the medical community that have heretofore been ignored.

Ba813 harboring Bacillus cereus, genetically closely related to Bacillus anthracis, causing nosocomial bloodstream infection: Bacterial virulence factors and clinical outcome

Bacillus cereus commonly causes catheter-related bloodstream infections (BSIs) in hospital settings, and occasionally occurs fatal central nervous system (CNS) complications. B. cereus harboring Ba813, a specific chromosomal marker of Bacillus anthracis, has been found in patients with severe infection and nosocomial BSI. However, the bacteriological profile and clinical feature of Ba813 (+) B. cereus are unclear. Fifty-three patients with B. cereus BSI were examined. Isolates were evaluated for Ba813, B. anthracis-related and food poisoning-related virulence, multilocus sequencing typing, and biofilm formation. Patients’ clinical records were reviewed retrospectively. The 53 isolates were comprised of 29 different sequence types in two distinct clades. Seventeen of the 53 (32%) B. cereus isolates including five sequence types possessed Ba813 and were classified into Clade-1/Cereus-III lineage which is most closely related to Anthracis lineage. No B. cereus possessed B. anthracis-related virulence genes. Ba813 (+) strains showed a lower prevalence of enterotoxin genes than Clade-2 strains (n = 4), but no difference from Clade-1. Ba813 (+) strains showed significantly lower biofilm formation than Clade-1/non-Cereus-III (n = 22) and Clade-2 strains, respectively. Compared to Clade-1/non-Cereus-III and Clade-2 B. cereus, Ba813 (+) strains were isolated more frequently from elderly patients, patients with indwelling central venous catheter rather than peripheral venous catheter, and patients who remained in the hospital for longer before BSI onset. No significant differences in disease severity or mortality were observed. Though two of the ten Ba813 (-) strains in Clade-1/Cereus III were isolated from the patients with CNS complication, no significant difference was observed in the bacterial profile and clinical characteristics among Clade-1/Cereus III strains. In conclusion, our report suggested that Ba813-harboring B. cereus strains, genetically closely related to B. anthracis, were abundant among B. cereus strains in the hospital setting, and might cause catheter-related nosocomial BSI. However, it did not affect the clinical outcomes.

Comparison of linezolid and vancomycin lock solutions with and without heparin against biofilm-producing bacteria

PURPOSE

The activity of linezolid and vancomycin lock solutions against biofilm-producing strains of Staphylococcus aureus, S. epidermidis, and Enterococcus faecalis was studied.

METHODS

Two strains each of methicillin-susceptible S. aureus (MSSA), methicillin-resistant S. aureus (MRSA), and S. epidermidis, and 1 strain of vancomycin-susceptible E. faecalis and vancomycin-resistant E. faecalis were tested against vancomycin and linezolid to assess prevention of biofilm formation and eradication of these pathogens within a formed biofilm. Activity was also tested in a 72-hour in vitro central venous catheter (CVC) model. After 24 hours of biofilm growth in a CVC, a lock solution containing vancomycin (2 or 5 mg/mL) or linezolid (1 or 2 mg/mL) alone or in combination with heparin sodium (5,000 units/mL with benzyl alcohol 0.45%) was instilled and incubated at 35 °C for 72 hr. Heparin and 0.9% sodium chloride injection were also tested.

RESULTS

Linezolid and vancomycin prevented biofilm formation below the minimum inhibitory concentration for 88% and 25% of isolates tested, respectively. The addition of preservative-containing heparin decreased the activity of vancomycin and linezolid lock solutions against all strains. Vancomycin 2- and 5-mg/mL lock solutions had the most activity against MSSA and E. faecalis strains (p < 0.01). Linezolid 2 mg/mL was the most active lock solution against the MRSA strains tested (p < 0.01). There were no significant differences in vancomycin or linezolid lock solution activity against S. epidermidis.

CONCLUSION

Heparin reduced activity of vancomycin and linezolid lock solutions against S. aureus, S. epidermidis, and E. faecalis biofilms. While linezolid or vancomycin lock solution reduced overall biofilm burden, it did not completely eradicate the bacteria at tested concentrations.

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

BACKGROUND

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

METHODS

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

FINDINGS

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

INTERPRETATION

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

FUNDING

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

70% Ethanol for Decontamination of Central Venous Lines Exposed to Calcineurin Inhibitors

BACKGROUND

Tacrolimus, commonly used for graft versus host disease prophylaxis is usually administered via a dedicated central venous line (CVL) and trough levels drawn from the unexposed lumen. Being an oil-based medication, it may be adsorbed to the inner lumen of the CVL and result in falsely high levels drawn from an inadvertently exposed lumen. There is no treatment for decontamination of such CVLs, and natural decay occurs over months before the CVL can be used to draw reliable trough levels.

OBJECTIVE

The primary objective of the study was to estimate the effectiveness of 70% ethanol locks for decontaminating CVLs exposed to tacrolimus.

METHODS

We studied the efficacy of 70% ethanol lock in decontaminating CVLs exposed to tacrolimus in patients during transplant. Trough tacrolimus levels were drawn from the exposed and unexposed (control) lumens at 8:00 am, followed by a 2-mL 70% ethanol lock instilled for a 2-hour dwell into the exposed (intervention) lumen. Trough tacrolimus levels were again drawn from both lumens at 8:00 pm and levels compared for efficacy.

RESULTS

All 20 sets showed a high 8 am trough level in the exposed intervention arm (median = 30 ng/mL), significantly greater ( P < 0.0001) than that in the control arm (median = 9.05 ng/mL), and were contaminated. After the 2-hour ethanol lock, 65% of the lumens were decontaminated. The difference between the control and intervention arms was no longer found to be statistically significant ( P = 0.0826).

CONCLUSION

A 2-hour 70% ethanol lock is effective for decontamination of CVLs exposed to tacrolimus.

Impact of a modified Broviac maintenance care bundle on bloodstream infections in paediatric cancer patients

Background: During intensive chemotherapy, bloodstream infection (BSI) represents an important complication in paediatric cancer patients. Most patients carry a long-term central venous access device (CVAD). Improved maintenance care of these vascular catheters may decrease the risk of BSI.

Methods: Intervention study (adapted CVAD prevention protocol) with two observation periods (P1: 09-2009 until 05-2011; P2: 09-2011 until 05-2013); prospective surveillance of all laboratory confirmed BSIs. In P2, ready to use sterile NaCl 0.9% syringes were used for CVAD flushing and octenidine/isopropanol for the disinfection of catheter hubs and 3-way stopcocks.

Results: During P1, 84 patients were included versus 81 patients during P2. There were no significant differences between the two patient populations in terms of median age, gender, underlying malignancy or disease status (first illness or relapse). Nearly all CVADs were Broviac catheters. The median duration from implantation to removal of the CVAD was 192 days (Inter-quartile-range (IQR); 110–288 days) in P1 and 191 days (IQR; 103–270 days) in P2. 28 BSI were diagnosed in 22 patients in P1 (26% of all patients experienced at least one BSI) and 15 BSI in 12 patients in P2 (15% of all patients). The corresponding results for incidence density (ID) were 0.44 (CI95 0.29–0.62) for P1 vs. 0.34 (0.19–0.53) BSI per 100 inpatient days for P2 and for incidence rate (IR) 7.76 (5.16–10.86) in P1 vs. 4.75 (2.66–7.43) BSI per 1,000 inpatient CVAD utilization days. In P1, 9 BSI were caused by CoNS vs. only 2 in P2 (IR 2.49; CI95 0.17–4.17 vs. 0.63; CI95 0.08–1.72). In P1 two BSI (7%) lead to early removal of the device. During P2 one CVAD was prematurely removed due to a Broviac-related BSI (6.7%).

Conclusion: The preventive protocol investigated in this study led to a reduction of BSI in paediatric cancer patients. This result was clinically relevant but – due to insufficient power in a single centre observation – the difference did not reach statistical significance. The most pronounced trend in BSI reduction was observed for CoNS infections. Thus, improving maintenance care of the CVAD may result in lower CVAD-linked infection rates. The higher acquisition cost of the ready to use NaCl 0.9% flushing syringes and octenidine/propanol hub disinfection were probably balanced by cost savings in the intervention period.

Searching for new strategies against polymicrobial biofilm infections: guanylated polymethacrylates kill mixed fungal/bacterial biofilms

OBJECTIVES

Biofilm-related human infections have high mortality rates due to drug resistance. Cohabitation of diverse microbes in polymicrobial biofilms is common and these infections present additional challenges for treatment compared with monomicrobial biofilms. Here, we address this therapeutic gap by assessing the potential of a new class of antimicrobial agents, guanylated polymethacrylates, in the treatment of polymicrobial biofilms built by two prominent human pathogens, the fungus Candida albicans and the bacterium Staphylococcus aureus.

METHODS

We used imaging and quantitative methods to test the antibiofilm efficacy of guanylated polymethacrylates, a new class of drugs that structurally mimic antimicrobial peptides. We further compared guanylated polymethacrylates with first-line antistaphylococcal and anti-Candida agents used as combinatorial therapy against polymicrobial biofilms.

RESULTS

Guanylated polymethacrylates were highly effective as a sole agent, killing both C. albicans and S. aureus when applied to established polymicrobial biofilms. Furthermore, they outperformed multiple combinations of current antimicrobial drugs, with one of the tested compounds killing 99.98% of S. aureus and 82.2% of C. albicans at a concentration of 128 mg/L. The extracellular biofilm matrix provided protection, increasing the MIC of the polymethacrylates by 2-4-fold when added to planktonic assays. Using the C. albicans bgl2ΔΔ mutant, we implicate matrix polysaccharide β-1,3 glucan in the mechanism of protection. Data for two structurally distinct polymers suggest that this mechanism could be minimized through chemical optimization of the polymer structure. Finally, we demonstrate that a potential application for these polymers is in antimicrobial lock therapy.

CONCLUSIONS

Guanylated polymethacrylates are a promising lead for the development of an effective monotherapy against C. albicans/S. aureus polymicrobial biofilms.

Ethanol and Isopropyl Alcohol Exposure Increases Biofilm Formation in Staphylococcus aureus and Staphylococcus epidermidis

Introduction

Alcohols, including ethanol and isopropyl alcohol, are used in clinical practice for disinfection and infection prevention. Recent studies, however, demonstrate that alcohols may enhance biofilm production in Staphylococci.

Methods

We quantified biofilm formation in the presence of ethanol and isopropyl alcohol in six different, well-characterized strains of Staphylococcus epidermidis and Staphylococcus aureus. After 24 h of biofilm development, each strain was exposed to normal saline (NS), ethanol, or isopropyl alcohol (40%, 60%, 80% and 95%) for additional 24 h incubation. Adherent biofilms were stained and optical density was determined. Viability of strains was also determined after alcohol exposure.

Results

Ethanol increased biofilm formation in all six strains compared to normal saline (p < 0.05). There was increased biofilm formation with increasing ethanol concentration. Isopropyl alcohol also increased biofilm formation with increasing alcohol concentration in all six strains (p < 0.01 vs NS). The slime-negative, chemical mutant strain of S. epidermidis increased biofilm formation after exposure to both alcohols, likely reverting back its primary phenotype through modulation of the intercellular adhesin repressor. All strains demonstrated viability after exposure to each alcohol concentration, though viability was decreased.

Conclusion

Ethanol and isopropyl alcohol exposure increases biofilm formation of S. aureus and S. epidermidis at concentrations used in clinical settings. Ethanol and isopropyl alcohol did not eradicate viable Staphylococci from formed biofilm.

Electronic supplementary material

The online version of this article (doi:10.1007/s40121-015-0065-y) contains supplementary material, which is available to authorized users.

Bloodstream infection in paediatric cancer centres--leukaemia and relapsed malignancies are independent risk factors

In a prospective multicentre study of bloodstream infection (BSI) from November 01, 2007 to July 31, 2010, seven paediatric cancer centres (PCC) from Germany and one from Switzerland included 770 paediatric cancer patients (58% males; median age 8.3 years, interquartile range (IQR) 3.8-14.8 years) comprising 153,193 individual days of surveillance (in- and outpatient days during intensive treatment). Broviac catheters were used in 63% of all patients and Ports in 20%. One hundred forty-two patients (18%; 95% CI 16 to 21%) experienced at least one BSI (179 BSIs in total; bacteraemia 70%, bacterial sepsis 27%, candidaemia 2%). In 57%, the BSI occurred in inpatients, in 79% after conventional chemotherapy. Only 56 % of the patients showed neutropenia at BSI onset. Eventually, patients with acute lymphoblastic leukaemia (ALL) or acute myeloblastic leukaemia (AML), relapsed malignancy and patients with a Broviac faced an increased risk of BSI in the multivariate analysis. Relapsed malignancy (16%) was an independent risk factor for all BSI and for Gram-positive BSI.

CONCLUSION

This study confirms relapsed malignancy as an independent risk factor for BSIs in paediatric cancer patients. On a unit level, data on BSIs in this high-risk population derived from prospective surveillance are not only mandatory to decide on empiric antimicrobial treatment but also beneficial in planning and evaluating preventive bundles.

WHAT IS KNOWN

• Paediatric cancer patients face an increased risk of nosocomial bloodstream infections (BSIs). • In most cases, these BSIs are associated with the use of a long-term central venous catheter (Broviac, Port), severe and prolonged immunosuppression (e.g. neutropenia) and other chemotherapy-induced alterations of host defence mechanisms (e.g. mucositis). What is New: • This study is the first multicentre study confirming relapsed malignancy as an independent risk factor for BSIs in paediatric cancer patients. • It describes the epidemiology of nosocomial BSI in paediatric cancer patients mainly outside the stem cell transplantation setting during conventional intensive therapy and argues for prospective surveillance programmes to target and evaluate preventive bundle interventions.

Incidence, Classification, and Risk Stratification forCandidaCentral Line–Associated Bloodstream Infections in Pediatric Patients at a Tertiary Care Children's Hospital, 2000–2010

Objective.

To identify risk factors for pediatricCandidacentral line-associated bloodstream infections (CLABSIs).

Design.

Retrospective case-control study.

Setting.

Freestanding tertiary care children's hospital.

Patients.

Patients withCandidaCLABSI from January 31, 2000, through December 31, 2010, compared with age- and year-matched controls.

Methods.

Demographics, comorbidities, presence of indwelling foreign bodies, exposure to antibiotics or corticosteroids, total parenteral nutrition (TPN) or blood transfusions, complications, and outcome were evaluated. Bivariate and then logistic regression were used to compare temporal trends and risk factors.

Results.

A total of 160CandidaCLABSI patients (median age, 1.96 years) were compared with 457 controls. Those withCandidaCLABSIs were more likely to have intestinal failure (adjusted odds ratio [aOR], 6.777 [95% confidence interval (CI), 2.315–19.839];P< .001), to have a gastrostomy tube in place (aOR, 4.156 [95% CI, 2.317–7.456];P< .001), and to receive TPN (aOR, 3.897 [95% CI, 2.403–6.319];P< .001) or blood transfusions (aOR, 2.990 [95% CI, 1.841–4.856];P< .001), and they had a 3-fold increase in mortality (aOR, 3.543 [95% CI, 1.501–8.364];P= .004).Candida albicanswas most common, butnon-albicansstrains resistant to amphotericin (C. lusitaniae) and fluconazole (C. glabrataandC. krusei) were also found.

Conclusions.

Those patients with intestinal failure, gastrostomy tube presence, and/or receipt of TPN and blood transfusions are at increased risk for development ofCandidaCLABSI.

Stability and compatibility of antimicrobial lock solutions

PURPOSE

Published stability and compatibility data on a growing array of solutions used for antimicrobial lock therapy (ALT) are reviewed.

SUMMARY

ALT involves the instillation of a highly concentrated antimicrobial, often in combination with an anticoagulant, into a central venous catheter (CVC) lumen; this technique is often used for prophylaxis after CVC insertion or as an adjunctive treatment in cases of central line-associated bloodstream infection (CLABSI) if catheter removal is not feasible. Optimal selection of stable and compatible antimicrobials and additives can maximize catheter dwell times, streamline pharmacy compounding practices, and help ensure patient safety. Of 98 articles on ALT solutions identified in a literature search, 17 met the prespecified criteria for the use of validated stability and compatibility methodology. Antimicrobials active against common CLABSI pathogens that may be appropriate for ALT include cefazolin, cefotaxime, ceftazidime, ciprofloxacin, daptomycin, gentamicin, linezolid, telavancin, ticarcillin-clavulanic acid, and vancomycin; validated data demonstrate the stability of these agents in solution with heparin or nonheparin anticoagulants over 72-96 hours or longer. Other antifungal agents and antiinfectives (e.g., ethyl alcohol) have been used in specific patients and ALT situations. The prolonged stability of several antimicrobial-additive combinations may allow for extended dwell times and less frequent lock solution exchanges.

CONCLUSION

Pharmacists' knowledge of diverse combinations of antimicrobial agents and additives in lock solutions, including several shown to be stable and compatible for extended periods, can help expand and optimize the use of ALT in both treatment and prophylactic modalities.

Ethanol lock therapy (E-Lock) in the prevention of catheter-related bloodstream infections (CR-BSI) after major heart surgery (MHS): a randomized clinical trial

BACKGROUND

Lock-therapy with antimicrobials has been used for the treatment and prevention of catheter-related bloodstream infections (CR-BSI). Experiences with Ethanol-Locks (E-locks) have included therapeutic interventions with variable results. Patients undergoing Major Heart Surgery (MHS) are a high-risk population for CR-BSI.The aim of this study was to assess the efficacy and tolerance to E-Locks in the prevention of CR-BSI of patients undergoing MHS.

METHODS AND FINDINGS

This is an academic, prospective, randomized, non-blinded and controlled clinical trial assessing the incidence of CR-BSI of patients with E-locks (E-lock) and the tolerance to the procedure in comparison with patients receiving conventional catheter-care (CCC). Patients undergoing MHS with intravascular catheters for more than 48 hours were randomly assigned into treatment or control group by a computer-generated list of randomly assigned numbers. In the treatment group, all their catheter lumens were locked with an ethanol solution at 70% for two hours, every three days (E-Locks). The control group received conventional catheter-care (CCC). Overall, 200 patients with 323 catheters were included in the study, which was stopped after 10 months due to adverse events. Of them, 179 catheters (113 patients) had E-Locks and 144 catheters (87 patients) were CCC. Euroscore Surgical Risk in both groups was 4.04 vs 4.07 p = 0.94 respectively. The results for the E-Locks and CCC were as follows: Incidence of CR-BSI/1000 days of exposure 2.1 vs 5.2 (p = 0.33), catheter tip colonization 14 (7.8%) vs 6 (4.2%) patients (p = 0.17), median length of hospital stay, 15 vs 16 days (p = 0.77). Seven patients (6.19%), all in the ethanol branch, had to discontinue the trial due to intolerance or adverse events.

CONCLUSIONS

We do not recommend prophylaxis of CR-BSI with ethanol-lock on a routine basis in patients undergoing Major Heart Surgery.

TRIAL REGISTRATION

Clinical Trials.gov NCT01229592.

Hemlock woolly adelgid and elongate hemlock scale induce changes in foliar and twig volatiles of eastern hemlock

Eastern hemlock (Tsuga canadensis) is in rapid decline because of infestation by the invasive hemlock woolly adelgid (Adelges tsugae; 'HWA') and, to a lesser extent, the invasive elongate hemlock scale (Fiorinia externa; 'EHS'). For many conifers, induced oleoresin-based defenses play a central role in their response to herbivorous insects; however, it is unknown whether eastern hemlock mobilizes these inducible defenses. We conducted a study to determine if feeding by HWA or EHS induced changes in the volatile resin compounds of eastern hemlock. Young trees were experimentally infested for 3 years with HWA, EHS, or neither insect. Twig and needle resin volatiles were identified and quantified by gas chromatography/mass spectrometry. We observed a suite of changes in eastern hemlock's volatile profile markedly different from the largely terpenoid-based defense response of similar conifers. Overall, both insects produced a similar effect: most twig volatiles decreased slightly, while most needle volatiles increased slightly. Only HWA feeding led to elevated levels of methyl salicylate, a signal for systemic acquired resistance in many plants, and benzyl alcohol, a strong antimicrobial and aphid deterrent. Green leaf volatiles, often induced in wounded plants, were increased by both insects, but more strongly by EHS. The array of phytochemical changes we observed may reflect manipulation of the tree's biochemistry by HWA, or simply the absence of functional defenses against piercing-sucking insects due to the lack of evolutionary contact with these species. Our findings verify that HWA and EHS both induce changes in eastern hemlock's resin chemistry, and represent the first important step toward understanding the effects of inducible chemical defenses on hemlock susceptibility to these exotic pests.

Ethanol lock therapy in pediatric hematology and oncology

Central venous catheters are essential for treatment of cancer and hematologic disorders in children. Central line-associated bloodstream infection (CLABSI) is the most common important complication and can lead to serious sequelae. Conventional antibiotic treatment is often unsuccessful. Ethanol lock therapy (ELT) has been shown to prevent CLABSI in various patient groups and might also be beneficial as adjunctive treatment for active infection. Efficacy and safety have not been adequately studied in the pediatric hematology/oncology population. Catheter occlusion and intraluminal clots have been reported. Routine use of ELT should not be recommended in this population until more data are available.