What's new in multidrug-resistant pathogens in the ICU?

A study of antibiotic prescription pattern in patients referred to tertiary care center in Northern India

Background

Tremendous infectious disease burden and rapid emergence of multidrug resistant pathogens continues to burden our healthcare system. Antibiotic stewardship program often implements antibiotic policies that help in preventing unnecessary use of antibiotics and in optimizing management. To develop such a policy for management of infections in the emergency unit, it is important to analyze the information regarding antibiotic prescription patterns in patients presenting to the emergency room referred from various healthcare settings. This study was conducted with the aforementioned background.

Methods

We conducted a prospective observational study in triage area of emergency unit of a tertiary care hospital. All the referred patients were screened for antibiotic prescription. Data extraction form was used to capture information on patient demographics, diagnosis and antibiotics prescribed. Antibiotic prescription details with regard to dosage, duration and frequency of antimicrobial administration were also recorded. Data were summarized using descriptive statistics as appropriate.

Results

Out of 517 screened patients, 300 were prescribed antimicrobials. Out of 29 antibiotics prescribed, 12 were prescribed in more than 90% of patients. Broad spectrum antibiotics accounted for 67.3% of prescriptions. In 129 out of 300 patients, no evidence of infectious etiology was found.

Conclusion

Our study highlights some common but serious lapses in antibiotic prescription patterns in patients referred from various healthcare settings. This emphasizes the need to provide training for rational use of antibiotics across healthcare settings.

Antibacterial activities of mono-, di- and tri-substituted triphenylamine-based phosphonium ionic liquids

We report the synthesis of new mono, di and tri phosphonium ionic liquids and the evaluation of their antibacterial activities on both Gram-positive and Gram-negative bacteria from the ESKAPE-group. Among the molecules synthesized some of them reveal a strong bactericidal activity (MIC = 0.5 mg/L) for Gram-positive bacteria (including resistant strains) comparable to that of standard antibiotics. A comparative Gram positive and Gram negative antibacterial activities shows that the nature of counter-ion has no significant effects. Interestingly, the increase of phosphonium lateral chains (from 4 to 8 carbons) results in a decrease of antibacterial activities. However, the increase of the spacer length has a positive influence on the activity on both Gram-positive and Gram-negative bacteria except for E. aerogenes. Finally, the increased charge density has no effect on the Gram-positive antibacterial activities (MIC between 2 and 4 mg/L) but seems to attenuate (except for P. aeruginosa) the discrimination between Gram-positive and Gram-negative. Overall these results suggest a unique mechanism of action of these triphenylamine-phosphonium ionic liquid derivatives.

Effective drug combination for Caenorhabditis elegans nematodes discovered by output-driven feedback system control technique

Infections from parasitic nematodes (or roundworms) contribute to a significant disease burden and productivity losses for humans and livestock. The limited number of anthelmintics (or antinematode drugs) available today to treat these infections are rapidly losing their efficacy as multidrug resistance in parasites becomes a global health challenge. We propose an engineering approach to discover an anthelmintic drug combination that is more potent at killing wild-type Caenorhabditis elegans worms than four individual drugs. In the experiment, freely swimming single worms are enclosed in microfluidic drug environments to assess the centroid velocity and track curvature of worm movements. After analyzing the behavioral data in every iteration, the feedback system control (FSC) scheme is used to predict new drug combinations to test. Through a differential evolutionary search, the winning drug combination is reached that produces minimal centroid velocity and high track curvature, while requiring each drug in less than their EC₅₀ concentrations. The FSC approach is model-less and does not need any information on the drug pharmacology, signaling pathways, or animal biology. Toward combating multidrug resistance, the method presented here is applicable to the discovery of new potent combinations of available anthelmintics on C. elegans, parasitic nematodes, and other small model organisms.

Daily bathing strategies and cross-transmission of multidrug-resistant organisms: Impact of chlorhexidine-impregnated wipes in a multidrug-resistant gram-negative bacteria endemic intensive care unit

BACKGROUND

Health-care associated infections are a major cause of morbidity and mortality in critical care units. The aim of this study is to evaluate the effectiveness of chlorhexidine gluconate (CHG)-impregnated wipes in the daily bathing of patients in an intensive care unit (ICU) to prevent cross-transmission and colonization by multidrug-resistant organisms (MDROs) METHODS: Prospective cohort study with an intervention of 11 months. The intervention consisted of using CHG-impregnated wipes for the daily bathing of patients on mechanical ventilation or colonized by MDROs. Monthly trends in the number of patients colonized by MDROs and the incidence of nosocomial infections were evaluated.

RESULTS

A total of 1,675 patients were admitted to the unit during the intervention period, and 430 (25.7%) were bathed with chlorhexidine wipes. A significant decrease was observed in the incidence of colonization by MDROs over the months (β = -0.209; r² = 0.549; P = .027), and in the number of patients colonized compared with the equivalent period of the previous year (22.0% vs 18.4%; P = .01). No significant decrease was observed in the incidence of nosocomial infection between the two periods (4.11% vs 4.57%; P = .355). No dermatologic problems were observed in the treated patients.

CONCLUSIONS

The use of CHG-impregnated wipes reduces cross-transmission and colonization by MDROs in the ICUs in an endemic situation because of multidrug-resistant Enterobacteriaceae.

Respiratory research networks in Europe and beyond: aims, achievements and aspirations for the 21st century

Healthcare-associated infection, such as intensive care unit (ICU)-related respiratory infections, remain the most frequently encountered morbidity of ICU admission, prolonging hospital stay and increasing mortality rates. The epidemiology of ICU-related respiratory infections, particularly nonventilated ICU-associated pneumonia and ventilator-associated tracheobronchitis, appears to be quite different among different countries. European countries have different prevalence, patterns and mechanism of resistance, as well as different treatments chosen by different attending physicians. The classical clinical research process in respiratory infections consists of the following loop: 1) identification of knowledge gaps; 2) systematic review and search for adequate answers; 3) generation of study hypotheses; 4) design of study protocols; 5) collection clinical data; 6) analysis and interpretation of the results; and 7) implementation of the results in clinical practice.

Extended infusion of beta-lactam antibiotics: optimizing therapy in critically-ill patients in the era of antimicrobial resistance

INTRODUCTION

Beta-lactams are at the cornerstone of therapy in critical care settings, but their clinical efficacy is challenged by the rise in bacterial resistance. Infections with multi-drug resistant organisms are frequent in intensive care units, posing significant therapeutic challenges. The problem is compounded by a dearth in the development of new antibiotics. In addition, critically-ill patients have unique physiologic characteristics that alter the drugs pharmacokinetics and pharmacodynamics. Areas covered: The prolonged infusion of antibiotics (extended infusion [EI] and continuous infusion [CI]) has been the focus of research in the last decade. As beta-lactams have time-dependent killing characteristics that are altered in critically-ill patients, prolonged infusion is an attractive approach to maximize their drug delivery and efficacy. Several studies have compared traditional dosing to EI/CI of beta-lactams with regard to clinical efficacy. Clinical data are primarily composed of retrospective studies and some randomized controlled trials. Several reports show promising results. Expert commentary: Reviewing the currently available evidence, we conclude that EI/CI is probably beneficial in the treatment of critically-ill patients in whom an organism has been identified, particularly those with respiratory infections. Further studies are needed to evaluate the efficacy of EI/CI in the management of infections with resistant organisms.

Systemic antibiotics for preventing ventilator-associated pneumonia in comatose patients: a systematic review and meta-analysis

BACKGROUND

Early-onset ventilator-associated pneumonia (EO-VAP) is the leading cause of morbidity and mortality in comatose patients. However, VAP prevention bundles focus mainly on late-onset VAP and may be less effective in preventing EO-VAP in comatose patients. Systemic antibiotic administration at the time of intubation may have a role in preventing EO-VAP. Therefore, we evaluated the effectiveness of systemic antibiotic administration in VAP prevention in comatose patients through a systematic review and meta-analysis.

METHODS

We searched for studies published through December 2015 that evaluated systemic antibiotic prophylaxis in comatose patients. Two authors independently selected and evaluated full-length reports of randomized clinical trials or prospective cohorts in patients aged >16 years that evaluated the impact of systemic antibiotics at the time of intubation on EO-VAP compared to placebo or no prophylaxis. The outcome variables were the incidence of EO-VAP, the duration of mechanical ventilation, ICU length of stay, and ICU mortality.

RESULTS

We identified 10,988 citations, yielding 26 articles for further analysis; three studies with 267 patients were finally analyzed. Most patients (n = 135) were comatose due to head trauma. Systemic antibiotic administration was associated with decreased incidence of EO-VAP (RR 0.32; 95% CI 0.19-0.54) and shorter ICU LOS (standardized mean difference -0.32; 95% CI -0.56 to -0.08), but had no effect on mortality (RR 1.03; 95% CI 0.7-1.53) or duration of mechanical ventilation (standardized mean difference -0.16; 95% CI -0.41 to 0.08).

CONCLUSIONS

Antibiotic prophylaxis in comatose patients reduced the incidence of EO-VAP and decreased the ICU stay slightly. Future trials are needed to confirm these results.

Biomarker-guided antibiotic therapy-strengths and limitations

Biomarkers as C-reactive protein (CRP) and procalcitonin (PCT) emerged as tools to help clinicians to diagnose infection and to properly initiate and define the duration of antibiotic therapy. Several randomized controlled trials, including adult critically ill patients, showed that PCT-guided antibiotic stewardship was repeatedly associated with a decrease in the duration of antibiotic therapy with no apparent harm. There are however some relevant limitations in these trials namely the low rate of compliance of PCT-guided algorithms, the high rate of exclusion (without including common clinical situations and pathogens) and the long duration of antibiotic therapy in control groups. Such limitations weakened the real impact of such algorithms in the clinical decision-making process and strengthened the concept that the initiation and the duration of antibiotic therapy cannot depend solely on a biomarker. Future efforts should address these limitations in order to better clarify the role of biomarkers on the complex and multifactorial issue of antibiotic management and to deeply understand its potential effect on mortality.

Duration of antibiotic therapy in the intensive care unit

There are certain well defined clinical situations where prolonged therapy is beneficial, but prolonged duration of antibiotic therapy is associated with increased resistance, medicalising effects, high costs and adverse drug reactions. The best way to decrease antibiotic duration is both to stop antibiotics when not needed (sterile invasive cultures with clinical improvement), not to start antibiotics when not indicated (treating colonization) and keep the antibiotic course as short as possible. The optimal duration of antimicrobial treatment for ventilator-associated pneumonia (VAP) is unknown, however, there is a growing evidence that reduction in the length of antibiotic courses to 7-8 days can minimize the consequences of antibiotic overuse in critical care, including antibiotic resistance, adverse effects, collateral damage and costs. Biomarkers like C-reactive protein (CRP) and procalcitonin (PCT) do have a valuable role in helping guide antibiotic duration but should be interpreted cautiously in the context of the clinical situation. On the other hand, microbiological criteria alone are not reliable and should not be used to justify a prolonged antibiotic course, as clinical cure does not equate to microbiological eradication. We do not recommend a 'one size fits all' approach and in some clinical situations, including infection with non-fermenting Gram-negative bacilli (NF-GNB) clinical evaluation is needed but shortening the antibiotic course is an effective and safe way to decrease inappropriate antibiotic exposure.