The role of carbapenems in the treatment of severe nosocomial respiratory tract infections

Perspectives on Antibiotic Stewardship Programs among Health Care Providers at Two University Hospitals in Egypt

The perspectives of healthcare professionals on antibiotic stewardship programs (ASPs) should be explored. Any antibiotic stewardship strategy must be individualized based on patient needs, prescription habits, and local resources. The current study aimed to explore the perspectives of healthcare providers on antibiotics stewardship and their awareness of these perspectives. Furthermore, potential barriers to the application of ASPs should be identified and addressed. This exploratory cross-sectional study utilized a qualitative method to evaluate critical care physicians, pediatricians, and clinical pharmacists (n = 43). The mean age of the physicians was 32 ± 1.5 years. Among them, approximately two-thirds (66%) were women. A thematic content analysis was performed to examine the responses of the participants and to prioritize the recommendations for and barriers to the implementation of ASPs from the perspective of healthcare providers. According to the interviewees, the primary obstacles include lack of time in implementation and monitoring and lack of awareness of the need for ASPs. All respondents recommended the implementation of supervised and continuous trainings. In conclusion, the abovementioned barriers must be adequately addressed to facilitate the implementation of ASPs.

Syndromic Testing in Infectious Diseases: From Diagnostic Stewardship to Antimicrobial Stewardship

The implementation into clinical practice of syndromic testing by multiplex polymerase chain reaction allows early etiological diagnosis and paves the way towards timely targeted treatment. However, there is stringent need for diagnostic stewardship, as multiplex testing can also come with a high risk of misdiagnosis if improperly ordered or interpreted. We report two cases that illustrate proper and improper diagnostic stewardship, having important implications for correct patient management and application of antimicrobial stewardship into current clinical practice.

Implementation of Antimicrobial Stewardship in the Healthcare Setting

Antimicrobial resistance (AMR) is a serious problem that poses an imminent threat to patient safety. But drug-resistant bacteria can be prevented from spreading in hospital facilities by implementing effective antimicrobial stewardship practices. Antimicrobial stewardship programs are a set of measures taken by an organization to optimize antimicrobial use, improve patient outcomes, reduce AMR and healthcare-associated infections, and save healthcare costs. Healthcare facilities should have a defined antimicrobial stewardship policy in place that is available to all stakeholders. The policy should be evidence-based, regularly updated, and communicated clearly both verbally and through visual means such as posters. All staff should be trained on the proper use of antimicrobials as well as how to report misuse. Antibiotic stewardship measures include: educating and screening patients, monitoring, updating policies, limiting the use of high-risk medications, developing and improving hand hygiene practices, tracing the path of each medication, using computerized alert probes, using computerized medication records, educating staff, and creating the culture of prevention. There are several ways that antimicrobial stewardship practices can be implemented in the healthcare setting, including limiting the use of antibiotics and promoting healthy behaviors. With these strategies in place, infections can be prevented from occurring in the first place.

The Five Ds of Outpatient Antibiotic Stewardship for Urinary Tract Infections

Urinary tract infections (UTI) are one of the most common indications for antibiotic prescriptions in the outpatient setting. Given rising rates of antibiotic resistance among uropathogens, antibiotic stewardship is critically needed to improve outpatient antibiotic use, including in outpatient clinics (primary care and specialty clinics) and emergency departments. Outpatient clinics are in general a neglected practice area in antibiotic stewardship programs, yet most antibiotic use in the United States is in the outpatient setting. This article provides a comprehensive review of antibiotic stewardship strategies for outpatient UTI in the adult population, with a focus on the "five Ds" of stewardship for UTI, including right diagnosis, right drug, right dose, right duration, and de-escalation. Stewardship interventions that have shown success for improving prescribing for outpatient UTI are discussed, including diagnostic stewardship strategies, such as reflex urine cultures, computerized decision support systems, and modified reporting of urine culture results. Among the many challenges to achieving stewardship for UTI in the outpatient setting, some of the most important are diagnostic uncertainty, increasing antibiotic resistance, limitations of guidelines, and time constraints of stewardship personnel and front-line providers. This article presents a stewardship framework, built on current evidence and expert opinion, that clinicians can use to guide their own outpatient management of UTI.

Compliance with the 4Ds of antimicrobial stewardship practice in a tertiary care centre

Background

Antimicrobial stewardship describes the practice of promoting the selection of the right drug, dosage, delivery and duration of antimicrobial therapy (the 4Ds) in order to curtail the emergence of resistant organisms. It is important to quantify the inappropriate use of antimicrobials in terms of percentage adherence to each of the 4Ds mentioned.

Methods

We undertook a prospective review of medical records of patients admitted to the medical wards of a tertiary care centre in North India. All patients on antimicrobials were included and their records reviewed for indication, drug, dose, delivery and duration (or by asking the treating physician if not documented). Adherence to the 4Ds was determined by referring to updated literature-based standard treatment guidelines (STGs) for each specific disease.

Results

Of 304 patients, drugs were appropriate and matched STGs in 218 (72%) patients, with adherence to the right dose in 210 (69%), route of delivery in 216 (71%) and duration in 197 (65%). Full adherence to the 4Ds was observed in 196 (64.5%). Maximum adherence was observed in treating skin and soft tissue infections (100%), while minimum adherence was observed in administering medical prophylaxis (40%). WHO Access, Watch and Reserve categories comprised 29%, 63% and 8.5% of all prescribed antibiotics, respectively.

Conclusions

The right drug, dose, delivery and duration of therapy are prescribed in 72%, 69%, 71%, and 65% of patients, respectively. In order to increase the adherence to 100%, bedside stewardship practices in the form of prospective audits and feedback must be improved. There is a need to integrate WHO AWaRe classification of antibiotics into treatment guidelines.

Infections in Older Adults

Infections in elderly patients can prove diagnostically challenging. Age-related factors affecting the immune system in older individuals contribute to nonspecific presentations. Other age-related factors and chronic conditions have symptoms that may or may not point to an infectious diagnosis. Delay in administration of antimicrobials can lead to poor outcomes; however, unnecessary administration of antimicrobials can lead to increased morbidity and contribute to the emergence of multidrug-resistant organisms. Careful clinical assessment and consideration of patient history and risk factors is crucial. When necessary, antimicrobials should be chosen that are appropriate for the diagnosis and deescalated as soon as possible.

Antimicrobial Stewardship: Fighting Antimicrobial Resistance and Protecting Global Public Health

Antimicrobial resistance (AMR) is a serious threat to global public health. It increases morbidity and mortality, and is associated with high economic costs due to its health care burden. Infections with multidrug-resistant (MDR) bacteria also have substantial implications on clinical and economic outcomes. Moreover, increased indiscriminate use of antibiotics during the COVID-19 pandemic will heighten bacterial resistance and ultimately lead to more deaths. This review highlights AMR's scale and consequences, the importance, and implications of an antimicrobial stewardship program (ASP) to fight resistance and protect global health. Antimicrobial stewardship (AMS), an organizational or system-wide health-care strategy, is designed to promote, improve, monitor, and evaluate the rational use of antimicrobials to preserve their future effectiveness, along with the promotion and protection of public health. ASP has been very successful in promoting antimicrobials' appropriate use by implementing evidence-based interventions. The "One Health" approach, a holistic and multisectoral approach, is also needed to address AMR's rising threat. AMS practices, principles, and interventions are critical steps towards containing and mitigating AMR. Evidence-based policies must guide the "One Health" approach, vaccination protocols, health professionals' education, and the public's awareness about AMR.

Review of antimicrobial resistance control strategies: low impact of prospective audit with feedback on bacterial antibiotic resistance within hospital settings

BACKGROUND

Antimicrobial stewardship constitutes an essential element of any concerted effort to tackle bacterial resistance, a rising public health threat both in community as well as hospital settings. The term comprises variable strategies which aim to optimise prescribing practices through either antibiotic restrictions or prospective audits of prescriptions with subsequent feedback to clinicians. Although highly debated, the actual effects of the latter on the antimicrobial susceptibility patterns of hospital flora are uncertain. The present study aims to review and evaluate the literature concerning the impact of persuasive stewardship strategies on antimicrobial resistance within hospitals.

MATERIALS AND METHODS

A literature review covering the period to 1st April 2020 was conducted using the PubMed/Medline, Embase, Global Health and CINAHL Plus databases.

RESULTS

Fifteen studies were retrieved, including twelve simple before-and-after, and three interrupted time-series studies. Audit frequency and compliance rates varied broadly. The rationale of treatment optimisation is not clear in most cases. Overall, surveillance of sentinel microorganisms through antibiograms indicates ambiguous results, with uncertainty as to whether the few successes are due to a causal effect, random incidence fluctuations, or confounding. The most informative approach targeted solely fluoroquinolones, reporting improvements in relevant Pseudomonas susceptibilities and MRSA, but without sufficient data on other effects of the strategy to assess its overall utility in clinical practice.

CONCLUSION

Higher standard research is needed to address the actual effects of persuasive stewardship strategies on antimicrobial susceptibility patterns. At present, they seem inadequate to play a decisive role in bacterial resistance control within hospitals.

Strategies to Prevent Healthcare-Associated Infections: A Narrative Overview

Healthcare-associated infections (HCAIs) are a major source of morbidity and mortality and are the second most prevalent cause of death. Furthermore, it has been reported that for every one-hundred patients admitted to hospital, seven patients in high-income economies and ten in emerging and low-income economies acquire at least one type of HCAI. Currently, almost all pathogenic microorganisms have developed antimicrobial resistance, and few new antimicrobials are being developed and brought to market. The literature search for this narrative review was performed by searching bibliographic databases (including Google Scholar and PubMed) using the search terms: "Strategies," "Prevention," and "Healthcare-Associated Infections," followed by snowballing references cited by critical articles. We found that although hand hygiene is a centuries-old concept, it is still the primary strategy used around the world to prevent HCAIs. It forms one of a bundle of approaches used to clean and maintain a safe hospital environment and to stop the transmission of contagious and infectious microorganisms, including multidrug-resistant microbes. Finally, antibiotic stewardship also has a crucial role in reducing the impact of HCAIs through conserving currently available antimicrobials.

Antimicrobial stewardship in dental practice

BACKGROUND

Antibiotic resistance is a global public health problem that is responsible for increased patient morbidity and mortality and financial burden. Dental antibiotic prescribing contributes to approximately 10% of all antibiotic prescriptions, and an estimated 80% of that prescribing is deemed inappropriate. Dental antimicrobial stewardship (AMS) has an important role to play in international efforts to tackle antibiotic resistance. The aim of the authors was to comment on the implementation of AMS strategies in outpatient dental practices.

METHODS

The authors included previous studies regarding outpatient antibiotic stewardship, longitudinal studies quantifying dispensed dental antibiotic prescription use, and interventional studies aimed at implementing AMS interventions in dentistry.

RESULTS

Researchers in several studies conducted trials regarding the use of various interventions, mostly comprising a combination of audit, feedback, dissemination of guidelines, and educational components to improve dental prescribing.

CONCLUSIONS AND PRACTICAL IMPLICATIONS

In regard to the establishment of an AMS strategy, aspects to be considered should include raising awareness about the risks of unnecessary use of antibiotics. Engaging and educating the entire dental team and patients, as well as collaborating with other specialized professionals, are important elements. Context-specific interventions with a methodical and measured approach are ideal.

An approach to antibiotic treatment in patients with sepsis

Sepsis is a medical emergency and life-threatening condition due to a dysregulated host response to infection, which is time-dependent and associated with unacceptably high mortality. Thus, when treating suspicious or confirmed cases of sepsis, clinicians must initiate broad-spectrum antimicrobials within the first hour of diagnosis. Optimizing antibiotic use is essential to ensure successful outcomes and to reduce adverse antibiotic effects, as well as preventing drug resistance. All likely pathogens involved should be considered to provide an appropriate antibiotic coverage. Clinicians must investigate on the previous risk of multidrug-resistant (MDR) pathogens, and the principle of individualized dosing should replace the principle of standard dosing. The loading dose is an initial higher dose of an antibiotic for all patients, yet an individualized treatment approach for further doses should be implemented according to pharmacokinetics (PK)/pharmacodynamics (PD) and the presence of renal/liver dysfunction. Extended or continuous infusion of beta-lactams and therapeutic drug monitoring (TDM) can help to achieve therapeutic levels of antimicrobials. Reevaluation of duration and appropriateness of treatment at regular intervals are also necessary. De-escalation and shortened courses of antimicrobials must be considered for most patients, except in some justified circumstances. Leadership, teamwork, antimicrobial stewardship (AS) frameworks, guideline’s recommendations on the optimal duration of treatments, de-escalation, and novel diagnostic stewardship approaches will help us to improve patients’ quality of care.

Antibiotic prescriptions in pediatric dentistry: A review

Most commonly prescribed drugs in pediatric dentistry are “Antibiotics.” Among Dentists, there is a trend toward overuse of antibiotics for nonindicated clinical conditions. This insufficient knowledge of the appropriate clinical indications for antibiotic prescriptions promotes the overuse of antibiotics and contributes to the emergence of antibiotic resistance among children. According to the various surveys done on the dental students, dentists and pediatric dentists on the antibiotic prescribing practices, overall, adherence to the professional clinical guidelines was low. There was a wide variation in dosages for all the antibiotics prescribed and for prolonged periods which were inconsistent with the recommendations. This paper reviews the current literature from the year 2000 to 2019. An electronic literature search was conducted in MEDLINE/PubMed, EBSCO host, and Google Scholar databases. The data was also collected manually from comprehensive textbooks. Some recommendations were also based on the opinion of experienced researchers and clinicians. Thus, this review aims at highlighting clinical indications, dosages, and duration of therapeutic antibiotic prescriptions for orofacial infections in the pediatric outpatients and at the same time creating an awareness, regarding the necessity of strictly adhering to the clinical guidelines for antibiotic prescriptions.

Role of antimicrobial restrictions in bacterial resistance control: a systematic literature review

BACKGROUND

Antimicrobial stewardship is considered as one of the most fundamental aspects of bacterial resistance control. Among the multitude of initiatives, restrictive strategies have been widely practiced in hospital settings. However, data concerning their potential effectiveness have not been methodically collected and evaluated to date.

AIM

To identify, collect and evaluate the available evidence regarding the impact of restrictive policies on bacterial resistance in hospital settings.

METHODS

A systematic literature review was conducted using the PubMed/Medline, Embase, Global Health and CINAHL Plus databases.

FINDINGS

In total, 5555 papers were retrieved in the search process, and 29 studies were included in the final analysis. There were no randomized studies, and the inherent limitations of the observational designs employed impede the deduction of safe conclusions. Seemingly beneficial interventions encompass the restriction of broad-spectrum cephalosporins in favour of beta-lactam/lactamase inhibitor combinations as well as the restriction of fluoroquinolones. Antimicrobial restrictions might also play a role in the control of vancomycin-resistant enterococci, while carbapenem stewardship in the form of the preferred use of ertapenem did not produce the anticipated results. Complex restrictions are not offered for informative comparative analyses. Hospital-wide policies could perhaps be superior to those confined to high-risk departments. Carbapenem-resistant Acinetobacter baumannii might be difficult to control through solely formulary interventions.

CONCLUSION

The presumably effective restrictive strategies rely mainly on inadequately tested hypotheses and low-quality evidence. Therefore, systematic, high-quality research is needed to confirm and expand comprehension of the subject so that the most successful policies are employed in the field.

The Role of Antibiotic Stewardship in Promoting Appropriate Antibiotic Use

Antibiotics are one of the most significant medical discoveries in human history. The widespread use of antibiotics has resulted in the emergence of antibiotic-resistant pathogens. This fact, coupled with the paucity of new antibiotic developments, has spurred efforts to combat antibiotic resistance. One of the most critical components of these efforts is antibiotic stewardship, a multidisciplinary endeavor, employing a collection of interventions in a variety of health care settings with the aim of promoting appropriate utilization of antibiotics. This article describes antibiotic stewardship programs and key practices used to minimize the development and spread of antibiotic-resistant pathogens including the optimization of antibiotic pharmacokinetics and pharmacodynamics, the application of rapid diagnostic tools, and the use of computerized provider order entry tools.

Antimicrobial Stewardship in the Emergency Department

The emergency department (ED) is the hub of the US health care system. Acute infectious diseases are frequently encountered in the ED setting, making this a critical setting for antimicrobial stewardship efforts. Systems level and behavioral stewardship interventions have demonstrated success in the ED setting but successful implementation depends on institutional support and the presence of a physician champion. Antimicrobial stewardship efforts in the ED should target high-impact areas: antibiotic prescribing for nonindicated respiratory tract conditions, such as bronchitis and sinusitis; overtreatment of asymptomatic bacteriuria; and using two antibiotics (double coverage) for uncomplicated cases of cellulitis or abscess.

Antimicrobial Stewardship in the Management of Sepsis

Sepsis represents a unique clinical dilemma with regard to antimicrobial stewardship. The standard approach to suspected sepsis in the emergency department centers on fluid resuscitation and timely broad-spectrum antimicrobials. The lack of gold standard diagnostics and evolving definitions for sepsis introduce a significant degree of diagnostic uncertainty that may raise the potential for inappropriate antimicrobial prescribing. Intervention bundles that combine traditional quality improvement strategies with emerging electronic health record-based clinical decision support tools and rapid molecular diagnostics represent the most promising approach to enhancing antimicrobial stewardship in the management of suspected sepsis in the emergency department.

Antimicrobial Stewardship: How the Microbiology Laboratory Can Right the Ship

Antimicrobial stewardship is a bundle of integrated interventions employed to optimize the use of antimicrobials in health care settings. While infectious-disease-trained physicians, with clinical pharmacists, are considered the main leaders of antimicrobial stewardship programs, clinical microbiologists can play a key role in these programs. This review is intended to provide a comprehensive discussion of the different components of antimicrobial stewardship in which microbiology laboratories and clinical microbiologists can make significant contributions, including cumulative antimicrobial susceptibility reports, enhanced culture and susceptibility reports, guidance in the preanalytic phase, rapid diagnostic test availability, provider education, and alert and surveillance systems. In reviewing this material, we emphasize how the rapid, and especially the recent, evolution of clinical microbiology has reinforced the importance of clinical microbiologists' collaboration with antimicrobial stewardship programs.

Biofilm Formation Restrained by Subinhibitory Concentrations of Tigecyclin in Acinetobacter baumannii Is Associated with Downregulation of Efflux Pumps

BACKGROUND

Tigecycline, one of the few therapeutic options against multidrug-resistant Acinetobacter baumannii, reaches subinhibitory serum concentrations only with cautious clinical dosing and pharmacokinetics. Subinhibitory concentrations of tigecycline might induce an A. baumannii biofilm.

METHODS

Biofilm formation was assessed via the crystal violet staining method. We further analyzed the main biofilm components with NaIO4, proteinase K, and DNase. Real-time RT-PCR was applied for quantitative detection of biofilm potential-associated genes.

RESULTS

In this study, A. baumannii proved to be a strong biofilm producer, and we found that proteins and extracellular DNA are crucial components of the A. baumannii biofilm. Quantitative real-time RT-PCR revealed positive correlations between biofilm formation restrained by subinhibitory concentrations of tigecycline and the expression of biofilm potential-associated genes, especially the AdeFGH efflux pump gene.

CONCLUSION

Our results suggest that downregulation of efflux pumps, especially the AdeFGH efflux pump, is probably responsible for the decline in biofilm formation in A. baumannii treated with subinhibitory concentrations of tigecyclin.

Antimicrobial stewardship through a one health lens

Purpose

– Antibiotic resistance (AR) is a global health crisis that is attracting focussed attention from healthcare, public health, governmental agencies, the public, and food producers. The purpose of this paper is to describe the work in Washington State to combat resistance and promote antimicrobial stewardship from a one health perspective.

Design/methodology/approach

– In 2014, the Washington State Department of Health convened a One Health Steering Committee and two workgroups to focus on AR, the One Health Antimicrobial Stewardship work group and the One Health Antimicrobial Resistance Surveillance work group. The group organized educational sessions to establish a basic understanding of epidemiological factors that contribute to resistance, including antibiotic use, transmission of resistant bacteria, and environmental contamination with resistant bacteria and antibiotic residues.

Findings

– The authors describe the varied uses of antibiotics; efforts to promote stewardship in human, and animal health, including examples from the USA and Europe; economic factors that promote use of antibiotics in animal agriculture; and efforts, products and next steps of the workgroups.

Originality/value

– In Washington, human, animal and environmental health experts are working collaboratively to address resistance from a one health perspective. The authors are establishing a multi-species resistance database that will allow tracking resistance trends in the region. Gaps include measurement of antibiotic use in humans and animals; integrated resistance surveillance information; and funding for AR and animal health research.

Population pharmacokinetics of imipenem in critically ill patients with suspected ventilator-associated pneumonia and evaluation of dosage regimens

AIMS

Significant alterations in the pharmacokinetics (PK) of antimicrobials have been reported in critically ill patients. We describe PK parameters of imipenem in intensive care unit (ICU) patients with suspected ventilator-associated pneumonia and evaluate several dosage regimens.

METHODS

This French multicentre, prospective, open-label study was conducted in ICU patients with a presumptive diagnosis of ventilator-associated pneumonia caused by Gram-negative bacilli, who empirically received imipenem intravenously every 8 h. Plasma imipenem concentrations were measured during the fourth imipenem infusion using six samples (trough, 0.5, 1, 2, 5 and 8 h). Data were analysed with a population approach using the stochastic approximation expectation maximization algorithm in Monolix 4.2. A Monte Carlo simulation was performed to evaluate the following six dosage regimens: 500, 750 or 1000 mg with administration every 6 or 8 h. The pharmacodynamic target was defined as the probability of achieving a fractional time above the minimal inhibitory concentration (MIC) of >40%.

RESULTS

Fifty-one patients were included in the PK analysis. Imipenem concentration data were best described by a two-compartment model with three covariates (creatinine clearance, total bodyweight and serum albumin). Estimated clearance (between-subject variability) was 13.2 l h(-1) (38%) and estimated central volume 20.4 l (31%). At an MIC of 4 μg ml(-1) , the probability of achieving 40% fractional time > MIC was 91.8% for 0.5 h infusions of 750 mg every 6 h, 86.0% for 1000 mg every 8 h and 96.9% for 1000 mg every 6 h.

CONCLUSIONS

This population PK model accurately estimated imipenem concentrations in ICU patients. The simulation showed that for these patients, the best dosage regimen of imipenem is 750 mg every 6 h and not 1000 mg every 8 h.

Alveolar and serum concentrations of imipenem in two lung transplant recipients supported with extracorporeal membrane oxygenation

Venovenous extracorporeal membrane oxygenation (ECMO) is increasingly used in patients with respiratory failure who fail conventional treatment. Postoperative pneumonia is the most common infection after lung transplantation (40%). Imipenem is frequently used for empirical treatment of nosocomial pneumonia in the intensive care unit. Nevertheless, few data are available on the impact of ECMO on pharmacokinetics, and no data on imipenem dosing during ECMO. Currently, no guidelines exist for antibiotic dosing during ECMO support. We report the cases of 2 patients supported with venovenous ECMO for refractory acute respiratory distress syndrome following single lung transplantation for pulmonary fibrosis, treated empirically with 1 g of imipenem intravenously every 6 h. Enterobacter cloacae was isolated from the respiratory sample of Patient 1 and Klebsiella pneumoniae was isolated from the respiratory sample of Patient 2. Minimum inhibitory concentrations of the 2 isolated strains were 0.125 and 0.25 mg/L, respectively. Both patients were still alive on day 28. This is the first report, to our knowledge, of imipenem concentrations in lung transplantation patients supported with ECMO. This study confirms high variability in imipenem trough concentrations in patients on ECMO and with preserved renal function. An elevated dosing regimen (4 g/24 h) is more likely to optimize drug exposure, and therapeutic drug monitoring is recommended, where available. Population pharmacokinetic studies are indicated to develop evidence-based dosing guidelines for ECMO patients.

Impact of antibiotic exposure on occurrence of nosocomial carbapenem-resistant Acinetobacter baumannii infection: a case control study

Carbapenem-resistant Acinetobacter baumannii (CRAB) infection is one of the most important healthcare associated diseases worldwide. Although antibiotic use is recognized as a risk factor for CRAB infection, the impact of antibiotic class and length of use on CRAB infection is still unclear. A case-control study was conducted in adult intensive care units and general wards of Songklanagarind Hospital, a tertiary-care hospital in southern Thailand, to investigate the effect of different antibiotic exposure and the duration of use on the risk of developing CRAB infection. Cases were defined as patients with carbapenem-susceptible A. baumannii (CSAB) or CRAB infection. Controls were randomly selected from patients and matched 1:1 with cases using ward and date of admission. Multinomial logistic regression was used to compute relative risk ratios (RRR) and 95% confidence intervals (CI) for CRAB infection. Of 197 cases with A. baumannii infection, there were 139 with CRAB infection and 58 with CSAB infection. Compared to the control group, use of fluoroquinolones, broad-spectrum cephalosporins and carbapenems for more than three days increased the risk of CRAB infection with RRR (95% CI) of 81.2 (38.1-862.7), 31.3 (9.9-98.7) and 112.1 (7.1-1770.6), respectively. The RRR (95% CI) for one to three day treatment of fluoroquinolones, broad-spectrum cephalosporins and carbapenems were 5.4 (0.8-38.7), 6.2 (0.1-353.2) and 63.3 (15.6-256.9), respectively. Long-term use of certain antibiotics and even short term use of carbapenems increased the risk of CRAB infection. In this setting, use of these antibiotics, especially carbapenems, should be limited to reduce CRAB infection.

Duration and cessation of antimicrobial treatment

Shortening the duration of antimicrobial therapy is an important strategy for optimizing patient care and reducing the spread of antimicrobial resistance. It is best used in the context of an overall approach to infection management that includes a focus on selecting the right initial drug and dosing regimen for empiric therapy, and de-escalation to a more narrowly focused drug regimen (or termination) based on subsequent culture results and clinical data. In addition to reducing resistance, other potential benefits of shorter antimicrobial courses include lowered antimicrobial costs, reduced risk of superinfections (including Clostridium difficile-associated diarrhea), reduced risk of antimicrobial-related organ toxicity, and improved drug compliance. There have been relatively few randomized clinical trials that study the optimal treatment durations for such serious infections as pneumonia (community- and healthcare/hospital-acquired), complicated intra-abdominal infection, and catheter-related bloodstream infection (CRBSI). Nonetheless, a growing number of studies have explored the possibilities of reducing the duration of antimicrobial therapy for at least certain patients with these infections, under certain circumstances. Professional organizations have compiled these data and used them to develop clinical practice guidelines to aid clinicians in choosing optimal treatment durations for individual patients. Many patients with hospital-acquired pneumonia, ventilator-associated pneumonia, or healthcare-associated pneumonia can be treated for 7-8 days, while 4-7 days and 14-day treatment durations may suffice for many patients with complicated intra-abdominal infections and uncomplicated CRBSI, respectively. This article first provides a general background on the rationale and data supporting shortened courses of antimicrobial therapy, before using 3 case studies to explore the practical implications of current knowledge and treatment guidelines when making decisions about treatment duration for individual patients with healthcare-associated pneumonia, complicated intra-abdominal infection, and CRBSI.

Antimicrobial stewardship

Antimicrobial resistance is increasing; however, antimicrobial drug development is slowing. Now more than ever before, antimicrobial stewardship is of the utmost importance as a way to optimize the use of antimicrobials to prevent the development of resistance and improve patient outcomes. This review describes the why, what, who, how, when, and where of antimicrobial stewardship. Techniques of stewardship are summarized, and a plan for implementation of a stewardship program is outlined.

[Available carbapenems: Properties and differences]

Carbapenems are β-lactam antibiotics endowed with a broader spectrum, activity and resistance to β-lactamases than other β-lactams. Due to their qualities, these antibiotics are crucial in empirical therapy, in the monotherapy of several severe hospital-acquired infections -and even that of some community-acquired infections- as well as in the directed therapy of infections due to multiresistant Gram-negative bacteria. All the available carbapenems have a similar spectrum, although there are significant differences in their antimicrobial activity, which in the long run determines the clinical indications of each carbapenem. The spectrum of ertapenem does not cover eminently nosocomial pathogens such as Pseudomonas aeruginosa and Acinetobacter spp., and hence this antibiotic is indicated in community-acquired infections requiring hospital treatment. In contrast, doripenem shows greater intrinsic activity than other carbapenems in extended spectrum beta-lactamase-producing enterobacteria and AmpC P. aeruginosa, Acinetobacter spp. and other non-fermentative and anaerobic microorganisms. Additionally, like the remaining carbapenems, doripenem has adequate pharmacokinetic characteristics and a favorable safety profile.

Comparative effects of carbapenems on bacterial load and host immune response in a Klebsiella pneumoniae murine pneumonia model

Doripenem is a carbapenem with potent broad-spectrum activity against Gram-negative pathogens, including antibiotic-resistant Enterobacteriaceae. As the incidence of extended-spectrum β-lactamase (ESBL)-producing Gram-negative bacilli is increasing, it was of interest to examine the in vivo comparative efficacy of doripenem, imipenem, and meropenem against a Klebsiella pneumoniae isolate expressing the TEM-26 ESBL enzyme. In a murine lethal lower respiratory infection model, doripenem reduced the Klebsiella lung burden by 2 log(10) CFU/g lung tissue over the first 48 h of the infection. Treatment of mice with meropenem or imipenem yielded reductions of approximately 1.5 log(10) CFU/g during this time period. Seven days postinfection, Klebsiella titers in the lungs of treated mice decreased an additional 2 log(10) CFU/g relative to those in the lungs of untreated control animals. Lipopolysaccharide (LPS) endotoxin release assays indicated that 6 h postinfection, meropenem- and imipenem-treated animals had 10-fold more endotoxin in lung homogenates and sera than doripenem-treated mice. Following doripenem treatment, the maximum endotoxin release postinfection (6 h) was 53,000 endotoxin units (EU)/ml, which was 2.7- and 6-fold lower than imipenem or meropenem-treated animals, respectively. While the levels of several proinflammatory cytokines increased in both the lungs and sera following intranasal K. pneumoniae inoculation, doripenem treatment, but not meropenem or imipenem treatment, resulted in significantly increased interleukin 6 levels in lung homogenates relative to those in lung homogenates of untreated controls, which may contribute to enhanced neutrophil killing of bacteria in the lung. Histological examination of tissue sections indicated less overall inflammation and tissue damage in doripenem-treated mice, consistent with improved antibacterial efficacy, reduced LPS endotoxin release, and the observed cytokine induction profile.

Treatment of acute bacterial exacerbations of chronic bronchitis

BACKGROUND

Controversies persist regarding the optimal management of patients with acute exacerbations of chronic bronchitis (AECB).

OBJECTIVE

To evaluate the available evidence on relevant issues, namely the need for administering antimicrobials in patients with AECB, the identification of the subgroup of patients with AECB needing antibiotics, the antimicrobial regimen of choice and its optimal duration, the existence of new agents, and the value of non-antimicrobial regimens for AECB.

METHODS

Data from various sources of evidence, including recent relevant meta-analyses, were appraised.

CONCLUSION

Administration of antimicrobial agents, combined with bronchodilators and systemic corticosteroids, is warranted in approximately half of AECBs (i.e., in bacterial exacerbations) to achieve a survival benefit. Simple clinical parameters, mainly sputum purulence, and biomarkers, such as procalcitonin, are useful in identifying patients requiring antibiotics. Advanced antibiotics (quinolones, macrolides, or amoxicillin/clavulanic acid) are more effective than 'old' antibiotics in AECB; regimens of short duration (for 5 days) are preferred. There is no difference between several classes of advanced antibiotics regarding their short-term effectiveness; however, quinolones are associated with better long-term outcomes than macrolides. Newer quinolones and new formulations of macrolides enrich clinicians' armamentarium against AECB.