Antimicrobial misuse in patients with positive blood cultures

Machine learning pipeline for blood culture outcome prediction using Sysmex XN-2000 blood sample results in Western Australia

BACKGROUND

Bloodstream infections (BSIs) are a significant burden on the global population and represent a key area of focus in the hospital environment. Blood culture (BC) testing is the standard diagnostic test utilised to confirm the presence of a BSI. However, current BC testing practices result in low positive yields and overuse of the diagnostic test. Diagnostic stewardship research regarding BC testing is increasing, and becoming more important to reduce unnecessary resource expenditure and antimicrobial use, especially as antimicrobial resistance continues to rise. This study aims to establish a machine learning (ML) pipeline for BC outcome prediction using data obtained from routinely analysed blood samples, including complete blood count (CBC), white blood cell differential (DIFF), and cell population data (CPD) produced by Sysmex XN-2000 analysers.

METHODS

ML models were trained using retrospective data produced between 2018 and 2019, from patients at Sir Charles Gairdner hospital, Nedlands, Western Australia, and processed at Pathwest Laboratory Medicine, Nedlands. Trained ML models were evaluated using stratified 10-fold cross validation.

RESULTS

Two ML models, an XGBoost model using CBC/DIFF/CPD features with boruta feature selection (BFS) , and a random forest model trained using CBC/DIFF features with BFS were selected for further validation after obtaining AUC scores of [Formula: see text] and [Formula: see text] respectively using stratified 10-fold cross validation. The XGBoost model obtained an AUC score of 0.76 on a internal validation set. The random forest model obtained AUC scores of 0.82 and 0.76 on internal and external validation datasets respectively.

CONCLUSIONS

We have demonstrated the utility of using an ML pipeline combined with CBC/DIFF, and CBC/DIFF/CPD feature spaces for BC outcome prediction. This builds on the growing body of research in the area of BC outcome prediction, and provides opportunity for further research.

Direct-from-Blood Detection of Pathogens: a Review of Technology and Challenges

Blood cultures have been the staple of clinical microbiology laboratories for well over half a century, but gaps remain in our ability to identify the causative agent in patients presenting with signs and symptoms of sepsis. Molecular technologies have revolutionized the clinical microbiology laboratory in many areas but have yet to present a viable alternative to blood cultures. There has been a recent surge of interest in utilizing novel approaches to address this challenge. In this minireview, I discuss whether molecular tools will finally give us the answers we need and the practical challenges of incorporating them into the diagnostic algorithm.

Improving awareness of blood culture indication, procedure and resource Utilization at Armed Forces Hospital Jizan, Saudi Arabia

Blood culture contamination (BCC) is a significant quality and safety issue in hospitals, as it leads to increase in unnecessary testing, admissions, antibiotic exposure and cost. This study is the first study on the BCC rates in Armed Forces Hospital Jizan (AFHJ), Saudi Arabia. The main goal of our quality improvement (QI) project was to reduce BCC rate in AFHJ from 7.5% to international benchmark (<3%) after January 2021 as well as to reduce the negativity rate. This study was conducted in AFHJ (KSA) including two major steps: first, development and implementation of QI interventions to reduce BCC and negativity rate in the AFHJ. Second, evaluation of the effectiveness of these interventions. The intervention was developed through QI methodologies, including fishbone diagramming and the plan-do-study-act cycle. Intervention effectiveness was evaluated using an interrupted time series analysis. Clear survey questionnaires were made and distributed to participants to get preaudit results.Then we started the education programme depending on the preaudit results. Soft copy of written steps of blood collection procedure and indication was done and sent to nurses and physicians. After that, direct observations of nurses involved in the process were conducted. Finally, post-training assessment using previous survey questionnaires was performed to get postaudit results. During the baseline period (preintervention period), 7.5% from blood culture were contaminated, compared with 1.8% during the intervention period (postintervention period). Rate of negative blood culture was reduced from 96% to 91%. Overall improvement of knowledge and awareness of the nurses and physicians clearly noted after intervention implementation. Fortunately, we have noted that the budget of microbiology would be reduced by 10%-12% as a result of our interventions. By standardising blood culture collection methods, optimising blood volume and nurses' education, we were able to develop a best practice for blood culture collection and to reduce BCC and negativity rate to a sustainable low rate at our hospital.

Effect of Blood Culture Contamination on Antibiotic Use in an Institution With Rapid Laboratory Methods and Phone-Based Clinical Follow-up of Blood Culture Results

In a multivariate analysis of 30 574 blood culture (BC) results, BC contamination was associated with only a small increase in antibiotic length of therapy compared to no-growth BCs (difference, 0.36 days [95% confidence interval, .05-.67]; P = .02). Stewardship processes at our institution appear to be effective in reducing the impact of BC contamination.

Blood Culture Utilization in the Hospital Setting: a Call for Diagnostic Stewardship

There has been significant progress in detection of bloodstream pathogens in recent decades with the development of more sensitive automated blood culture detection systems and the availability of rapid molecular tests for faster organism identification and detection of resistance genes. However, most blood cultures in clinical practice do not grow organisms, suggesting that suboptimal blood culture collection practices (e.g., suboptimal blood volume) or suboptimal selection of patients to culture (i.e., blood cultures ordered for patients with low likelihood of bacteremia) may be occurring. A national blood culture utilization benchmark does not exist, nor do specific guidelines on when blood cultures are appropriate or when blood cultures are of low value and waste resources. Studies evaluating the potential harm associated with excessive blood cultures have focused on blood culture contamination, which has been associated with significant increases in health care costs and negative consequences for patients related to exposure to unnecessary antibiotics and additional testing. Optimizing blood culture performance is important to ensure bloodstream infections (BSIs) are diagnosed while minimizing adverse events from overuse. In this review, we discuss key factors that influence blood culture performance, with a focus on the preanalytical phase, including technical aspects of the blood culture collection process and blood culture indications. We highlight areas for improvement and make recommendations to improve current blood culture practices among hospitalized patients.

Utility of cell-free DNA concentrations and illness severity scores to predict survival in critically ill neonatal foals

Plasma cell-free DNA (cfDNA) levels have been associated with disease and survival status in septic humans and dogs. To date, studies investigating cfDNA levels in association with critical illness in foals are lacking. We hypothesized that cfDNA would be detectable in the plasma of foals, that septic and sick-nonseptic foals would have significantly higher cfDNA levels compared to healthy foals, and that increased cfDNA levels would be associated with non-survival. Animals used include 80 foals of 10 days of age or less admitted to a tertiary referral center between January and July, 2020 were stratified into three categories: healthy (n = 34), sick non-septic (n = 11) and septic (n = 35) based on specific criteria. This was a prospective clinical study. Blood was collected from critically ill foals at admission or born in hospital for cfDNA quantification and blood culture. Previously published sepsis score (SS) and neonatal SIRS score (NSIRS) were also calculated. SS, NSIRS, blood culture status and cfDNA concentrations were evaluated to predict survival. Continuous variables between groups were compared using Kruskal-Wallis ANOVA with Dunn’s post hoc test. Comparisons between two groups were assessed using the Mann-Whitney U-test or Spearman rank for correlations. The performance of cfDNA, sepsis score and NSIRS score to predict survival was assessed by receiver operator characteristic (ROC) curve analysis including area under the curve, sensitivity and specificity using cutoffs. Plasma cfDNA was detectable in all foals. No significant differences in cfDNA concentration were detected between healthy foals and septic foals (P = 0.65) or healthy foals and sick non-septic foals (P = 0.88). There was no significant association between cfDNA and culture status, SS, NSIRS or foal survival. SS (AUC 0.85) and NSIRS (AUC 0.83) were superior to cfDNA (AUC 0.64) in predicting survival. Although cfDNA was detectable in foal plasma, it offers negligible utility to diagnose sepsis or predict survival in critical illness in neonates.

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.

A Diagnostic Stewardship Intervention To Improve Blood Culture Use among Adult Nonneutropenic Inpatients: the DISTRIBUTE Study

Interventions to optimize blood culture (BCx) practices in adult inpatients are limited. We conducted a before-after study evaluating the impact of a diagnostic stewardship program that aimed to optimize BCx use in a medical intensive care unit (MICU) and five medicine units at a large academic center. The program included implementation of an evidence-based algorithm detailing indications for BCx use and education and feedback to providers about BCx rates and indication inappropriateness. Neutropenic patients were excluded. BCx rates from contemporary control units were obtained for comparison. The primary outcome was the change in BCxs ordered with the intervention. Secondary outcomes included proportion of inappropriate BCx, solitary BCx, and positive BCx. Balancing metrics included compliance with the Centers for Medicare and Medicaid Services (CMS) SEP-1 BCx component, 30-day readmission, and all-cause in-hospital and 30-day mortality. After the intervention, BCx rates decreased from 27.7 to 22.8 BCx/100 patient-days (PDs) in the MICU (P = 0.001) and from 10.9 to 7.7 BCx/100 PD for the 5 medicine units combined (P < 0.001). BCx rates in the control units did not decrease significantly (surgical intensive care unit [ICU], P = 0.06; surgical units, P = 0.15). The proportion of inappropriate BCxs did not significantly change with the intervention (30% in the MICU and 50% in medicine units). BCx positivity increased in the MICU (from 8% to 11%, P < 0.001). Solitary BCxs decreased by 21% in the medicine units (P < 0.001). Balancing metrics were similar before and after the intervention. BCx use can be optimized with clinician education and practice guidance without affecting sepsis quality metrics or mortality.

A proposal for a comprehensive approach to infections across the surgical pathway

Despite evidence supporting the effectiveness of best practices in infection prevention and management, many healthcare workers fail to implement them and evidence-based practices tend to be underused in routine practice. Prevention and management of infections across the surgical pathway should always focus on collaboration among all healthcare workers sharing knowledge of best practices. To clarify key issues in the prevention and management of infections across the surgical pathway, a multidisciplinary task force of experts convened in Ancona, Italy, on May 31, 2019, for a national meeting. This document represents the executive summary of the final statements approved by the expert panel.

Diversion Principle Reduces Skin Flora Contamination Rates in a Community Hospital

CONTEXT.—

Blood culture contamination is a common problem faced by medical centers and leads to significant cost. A possible method to reduce contamination is to discard the initial aliquot of blood, which contains skin and bacteria.

OBJECTIVE.—

To determine whether the rate of contaminant blood cultures could be reduced by changing the order of draw to divert the first 7 mL to a gold- or green-top tube.

DESIGN.—

A preintervention and postintervention study was conducted. During the 18-month intervention phase (September 2015-February 2017), all nurses in the emergency department and inpatient floor phlebotomists collected blood cultures by drawing the first 7 mL of blood into a gold- or green-top tube followed by drawing blood for blood culture bottles. The 18 months immediately preceding the study period (February 2014-July 2015) were used for comparison.

RESULTS.—

There was an overall statistically significant decrease in contamination rate from 2.46% in the prediversion protocol group to 1.70% in the postdiversion protocol group (P < .001). Emergency department drawn cultures and inpatient cultures showed significant decrease in contamination rates between the preprotocol and postprotocol groups, 2.92% versus 1.95% (P < .001) for emergency department, and 1.82% versus 1.31% (P = .03) for inpatient. We noted less month-to-month variation during the study period compared with the preintervention period.

CONCLUSIONS.—

By using this simple diversion method, we were able to improve blood culture contamination rates for our emergency department and inpatients while incurring no added cost to the procedure.

Emerging Technologies for Molecular Diagnosis of Sepsis

Rapid and accurate profiling of infection-causing pathogens remains a significant challenge in modern health care. Despite advances in molecular diagnostic techniques, blood culture analysis remains the gold standard for diagnosing sepsis. However, this method is too slow and cumbersome to significantly influence the initial management of patients. The swift initiation of precise and targeted antibiotic therapies depends on the ability of a sepsis diagnostic test to capture clinically relevant organisms along with antimicrobial resistance within 1 to 3 h. The administration of appropriate, narrow-spectrum antibiotics demands that such a test be extremely sensitive with a high negative predictive value. In addition, it should utilize small sample volumes and detect polymicrobial infections and contaminants. All of this must be accomplished with a platform that is easily integrated into the clinical workflow. In this review, we outline the limitations of routine blood culture testing and discuss how emerging sepsis technologies are converging on the characteristics of the ideal sepsis diagnostic test. We include seven molecular technologies that have been validated on clinical blood specimens or mock samples using human blood. In addition, we discuss advances in machine learning technologies that use electronic medical record data to provide contextual evaluation support for clinical decision-making.

Male veterans with complicated urinary tract infections: Influence of a patient-centered antimicrobial stewardship program

BACKGROUND

The influence of antimicrobial stewardship programs (ASPs) on outcomes in male veterans treated for complicated urinary tract infection has not been determined.

METHODS

This was a retrospective cohort study encompassing the study period January 1, 2005-October 31, 2014, which was conducted at a 150-bed Veterans Affairs Healthcare System facility in Buffalo, NY. Male veterans admitted for treatment of complicated urinary tract infection were identified using ICD-9-CM codes. Outcomes before and after implementation of a patient-centered ASP, including duration of antibiotic therapy, length of hospitalization, readmission within 30 days, and Clostridium difficile infection were compared. Interventions resulting from the ASP were categorized.

RESULTS

Of the 1,268 patients screened, 241 met criteria for inclusion in the study (n = 118 and n = 123 in the pre-ASP and ASP group, respectively). Duration of antibiotic therapy was significantly shorter in the ASP group (10.32 days vs 11.96 days; P < .0001), as was length of hospitalization (5.76 days vs 6.76 days; P = .015). There was no difference in 30-day readmission. A total of 170 interventions were identified that resulted from the ASP (1.39 interventions per patient).

CONCLUSIONS

ASPs may be useful to improve clinical outcomes in men with complicated urinary tract infection. Implementation of an ASP was associated with significant decreases in duration of antibiotic therapy and length of hospitalization, without adversely affecting 30-day readmission rates.

Controlling Use of Antimicrobials in a Community Teaching Hospital

Objective.

To test the hypothesis that antibiotic use could be controlled or improved in a community teaching hospital, with improvement defined as reductions in overall use, overall cost, and antimicrobial resistance.

Design.

Interventional study with historical comparison.

Setting.

A not-for-profit, 900-bed community general hospital with residents in medicine, surgery, obstetrics-gynecology, and psychiatry.

Participants.

Physicians who requested any of the targeted antibiotics.

Interventions.

Three categories of inpatient antibiotic orders were monitored beginning in April 2001: conversion from intravenous to oral administration for selected highly bioavailable antimicrobials, cessation of perioperative prophylaxis within 24 hours for patients undergoing clean and clean-contaminated surgery, and consultation with an infectious diseases physician before continuing administration of selected drugs beyond 48 hours. Data were analyzed after the first 33 months. Patient outcomes were reviewed during the hospital stay and at readmission if it occurred within 30 days after discharge.

Results.

From April 2001 through December 2003, a total of 1426 requests for antimicrobial therapy met criteria for intervention. Overall physician compliance with the program was 76%, ranging from 57% for perioperative prophylaxis to 92% for intravenous to oral conversion. Antimicrobial costs per patient-day decreased by 31%, from $13.67 in 2000 (before program implementation) to $9.41 in 2003. Total savings in acquisition costs were $1,841,203 for the 3-year period. Resistance to numerous drugs among Klebsiella pneumoniae isolates was also significantly reduced.

Conclusions.

A program to improve the use of antibiotics in a community hospital was successful in reducing overall use, overall cost, and antimicrobial resistance.

Effectiveness of Practices To Increase Timeliness of Providing Targeted Therapy for Inpatients with Bloodstream Infections: a Laboratory Medicine Best Practices Systematic Review and Meta-analysis

BACKGROUND

Bloodstream infection (BSI) is a major cause of morbidity and mortality throughout the world. Rapid identification of bloodstream pathogens is a laboratory practice that supports strategies for rapid transition to direct targeted therapy by providing for timely and effective patient care. In fact, the more rapidly that appropriate antimicrobials are prescribed, the lower the mortality for patients with sepsis. Rapid identification methods may have multiple positive impacts on patient outcomes, including reductions in mortality, morbidity, hospital lengths of stay, and antibiotic use. In addition, the strategy can reduce the cost of care for patients with BSIs.

OBJECTIVES

The purpose of this review is to evaluate the evidence for the effectiveness of three rapid diagnostic practices in decreasing the time to targeted therapy for hospitalized patients with BSIs. The review was performed by applying the Centers for Disease Control and Prevention's (CDC's) Laboratory Medicine Best Practices Initiative (LMBP) systematic review methods for quality improvement (QI) practices and translating the results into evidence-based guidance (R. H. Christenson et al., Clin Chem 57:816-825, 2011, http://dx.doi.org/10.1373/clinchem.2010.157131).

SEARCH STRATEGY

A comprehensive literature search was conducted to identify studies with measurable outcomes. A search of three electronic bibliographic databases (PubMed, Embase, and CINAHL), databases containing "gray" literature (unpublished academic, government, or industry evidence not governed by commercial publishing) (CIHI, NIHR, SIGN, and other databases), and the Cochrane database for English-language articles published between 1990 and 2011 was conducted in July 2011.

DATES OF SEARCH

The dates of our search were from 1990 to July 2011.

SELECTION CRITERIA

Animal studies and non-English publications were excluded. The search contained the following medical subject headings: bacteremia; bloodstream infection; time factors; health care costs; length of stay; morbidity; mortality; antimicrobial therapy; rapid molecular techniques, polymerase chain reaction (PCR); in situ hybridization, fluorescence; treatment outcome; drug therapy; patient care team; pharmacy service, hospital; hospital information systems; Gram stain; pharmacy service; and spectrometry, mass, matrix-assisted laser desorption-ionization. Phenotypic as well as the following key words were searched: targeted therapy; rapid identification; rapid; Gram positive; Gram negative; reduce(ed); cost(s); pneumoslide; PBP2; tube coagulase; matrix-assisted laser desorption/ionization time of flight; MALDI TOF; blood culture; EMR; electronic reporting; call to provider; collaboration; pharmacy; laboratory; bacteria; yeast; ICU; and others. In addition to the electronic search being performed, a request for unpublished quality improvement data was made to the clinical laboratory community.

MAIN RESULTS

Rapid molecular testing with direct communication significantly improves timeliness compared to standard testing. Rapid phenotypic techniques with direct communication likely improve the timeliness of targeted therapy. Studies show a significant and homogeneous reduction in mortality associated with rapid molecular testing combined with direct communication.

AUTHORS' CONCLUSIONS

No recommendation is made for or against the use of the three assessed practices of this review due to insufficient evidence. The overall strength of evidence is suggestive; the data suggest that each of these three practices has the potential to improve the time required to initiate targeted therapy and possibly improve other patient outcomes, such as mortality. The meta-analysis results suggest that the implementation of any of the three practices may be more effective at increasing timeliness to targeted therapy than routine microbiology techniques for identification of the microorganisms causing BSIs. Based on the included studies, results for all three practices appear applicable across multiple microorganisms, including methicillin-resistant Staphylococcus aureus (MRSA), methicillin-sensitive S. aureus (MSSA), Candida species, and Enterococcus species.

A Qualitative Analysis of Implementation of Antimicrobial Stewardship at 3 Academic Hospitals: Understanding the Key Influences on Success

BACKGROUND

Inappropriate use of antimicrobials is linked to the development and spread of drug-resistant pathogens and is associated with increased morbidity, mortality, lengths of hospital stay, and health care costs. "Antimicrobial stewardship" is the umbrella term for an evidence-based knowledge translation strategy involving comprehensive quality improvement activities to optimize the use of antimicrobials, improve patient outcomes, reduce the development of antimicrobial resistance and hospital-acquired infections such as Clostridium difficile, and decrease health care costs.

OBJECTIVE

To assess the perceptions and experiences of antimicrobial stewardship program leaders in terms of clinicians' attitudes toward and behaviours related to antimicrobial prescribing.

METHODS

In this qualitative study, semistructured interviews were conducted with 6 antimicrobial stewards (2 physicians and 4 pharmacists) at 3 academic hospitals between June and August 2013.

RESULTS

The following 3 key themes emerged from the interviews: getting the right people on board, building collegial relationships, and rapidly establishing a track record. The study results elucidated the role and mechanisms that the program leader and other antimicrobial stewards used to influence other clinicians to engage in effective utilization of antimicrobials. The results also highlighted the methods employed by members of the antimicrobial stewardship team to tailor their strategies to the local context and to stakeholders of participating units; to gain credibility by demonstrating the impact of the antimicrobial stewardship program on clinical outcomes and cost; and to engage senior leaders to endorse and invest in the antimicrobial stewardship program, thereby adding to the antimicrobial stewards' credibility and their ability to influence the uptake of effective antimicrobial use.

CONCLUSIONS

Collectively, these results offer insight into processes and mechanisms of influence employed by antimicrobial stewards to enhance antimicrobial use among clinicians, which can in turn inform future implementation of antimicrobial stewardship and strategies for organizational change in hospitals.

The Likelihood of Hospital Readmission Among Patients With Hospital-Onset Central Line-Associated Bloodstream Infections

OBJECTIVE

To determine whether central line-associated bloodstream infections (CLABSIs) increase the likelihood of readmission.

DESIGN

Retrospective matched cohort study for the years 2008-2009.

SETTING

Acute care hospitals.

PARTICIPANTS

Medicare recipients. CLABSI and readmission status were determined by linking National Healthcare Safety Network surveillance data to the Centers for Medicare and Medicaid Services' Medical Provider and Analysis Review in 8 states. Frequency matching was used on International Classification of Diseases, Ninth Revision, Clinical Modification procedure code category and intensive care unit status.

METHODS

We compared the rate of readmission among patients with and without CLABSI during an index hospitalization. Cox proportional hazard analysis was used to assess rate of readmission (the first hospitalization within 30 days after index discharge). Multivariate models included the following covariates: race, sex, length of index hospitalization stay, central line procedure code, Gagne comorbidity score, and individual chronic conditions.

RESULTS

Of the 8,097 patients, 2,260 were readmitted within 30 days (27.9%). The rate of first readmission was 7.1 events/person-year for CLABSI patients and 4.3 events/person-year for non-CLABSI patients (P<.001). The final model revealed a small but significant increase in the rate of 30-day readmissions for patients with a CLABSI compared with similar non-CLABSI patients. In the first readmission for CLABSI patients, we also observed an increase in diagnostic categories consistent with CLABSI, including septicemia and complications of a device.

CONCLUSIONS

Our analysis found a statistically significant association between CLABSI status and readmission, suggesting that CLABSI may have adverse health impact that extends beyond hospital discharge.

Antimicrobial Stewardship Programs: Appropriate Measures and Metrics to Study their Impact

Antimicrobial stewardship is a new field that struggles to find the right balance between meaningful and useful metrics to study the impact of antimicrobial stewardship programs (ASPs). ASP metrics primarily measure antimicrobial use, although microbiological resistance and clinical outcomes are also important measures of the impact an ASP has on a hospital and its patient population. Antimicrobial measures looking at consumption are the most commonly used measures, and are focused on defined daily doses, days of therapy, and costs, usually standardized per 1,000 patient-days. Each measure provides slightly different information, with their own upsides and downfalls. Point prevalence measurement of antimicrobial use is an increasingly used approach to understanding consumption that does not entirely rely on sophisticated electronic information systems, and is also replicable. Appropriateness measures hold appeal and promise, but have not been developed to the degree that makes them useful and widely applicable. The primary reason why antimicrobial stewardship is necessary is the growth of antimicrobial resistance. Accordingly, antimicrobial resistance is an important metric of the impact of an ASP. The most common approach to measuring resistance for ASP purposes is to report rates of common or important community- or nosocomial-acquired antimicrobial-resistant organisms, such as methicillin-resistant Staphylococcus aureus and Clostridium difficile. Such an approach is dependent on detection methods, community rates of resistance, and co-interventions, and therefore may not be the most accurate or reflective measure of antimicrobial stewardship interventions. Development of an index to reflect the net burden of resistance holds theoretical promise, but has yet to be realized. Finally, programs must consider patient outcome measures. Mortality is the most objective and reliable method, but has several drawbacks. Disease- or organism-specific mortality, or cure, are increasingly used metrics.

Use of a structured panel process to define quality metrics for antimicrobial stewardship programs

INTRODUCTION

Antimicrobial stewardship programs are being implemented in health care to reduce inappropriate antimicrobial use, adverse events, Clostridium difficile infection, and antimicrobial resistance. There is no standardized approach to evaluate the impact of these programs.

OBJECTIVE

To use a structured panel process to define quality improvement metrics for evaluating antimicrobial stewardship programs in hospital settings that also have the potential to be used as part of public reporting efforts.

DESIGN

A multiphase modified Delphi technique.

SETTING

Paper-based survey supplemented with a 1-day consensus meeting.

PARTICIPANTS

A 10-member expert panel from Canada and the United States was assembled to evaluate indicators for relevance, effectiveness, and the potential to aid quality improvement efforts.

RESULTS

There were a total of 5 final metrics selected by the panel: (1) days of therapy per 1000 patient-days; (2) number of patients with specific organisms that are drug resistant; (3) mortality related to antimicrobial-resistant organisms; (4) conservable days of therapy among patients with community-acquired pneumonia (CAP), skin and soft-tissue infections (SSTI), or sepsis and bloodstream infections (BSI); and (5) unplanned hospital readmission within 30 days after discharge from the hospital in which the most responsible diagnosis was one of CAP, SSTI, sepsis or BSI. The first and second indicators were also identified as useful for accountability purposes, such as public reporting.

CONCLUSION

We have successfully identified 2 measures for public reporting purposes and 5 measures that can be used internally in healthcare settings as quality indicators. These indicators can be implemented across diverse healthcare systems to enable ongoing evaluation of antimicrobial stewardship programs and complement efforts for improved patient safety.

Behavior change strategies to influence antimicrobial prescribing in acute care: a systematic review

BACKGROUND

Antimicrobial use in acute care is widely reported to be suboptimal. Inappropriate use of antimicrobials is a major contributing factor to the emergence of multidrug resistance and health care-associated infection. Addressing prescribing behavior is a key component of antimicrobial stewardship.

METHODS

We performed a novel systematic review of both qualitative and quantitative literature on antimicrobial prescribing behavior in acute care. We assessed the extent to which behavioral sciences and social marketing were used and whether this could be related to the effectiveness of reported outcomes. MEDLINE, Excerpta Medica Database (EMBASE), Applied Social Sciences Index and Abstracts (ASSIA), Business Source Complete, The Cochrane Library, PsychInfo, Database of Abstracts of Reviews of Effectiveness (DARE) and Health Management Information Consortium (HMIC) were searched for studies undertaken during the period January 1999-April 2011 and published in English.

RESULTS

Five qualitative and 5 quantitative studies met the quality criteria. Qualitative studies highlight the predominant influence of social norms, attitudes, and beliefs on antimicrobial prescribing behavior. Quantitative studies reporting interventions to optimize antimicrobial prescribing behavior do not use theoretical science or primary research to inform the design and choice of the interventions deployed.

CONCLUSIONS

Despite qualitative evidence demonstrating the impact of behavioral determinants and social norms on prescribing, these influences are not given due consideration in the design and evaluation of interventions. To ensure a better understanding of prescribing behaviors and to improve the quality of interventions and research in this area, the incorporation and application of behavioral sciences supported by appropriate multidisciplinary collaboration is recommended.

Strategies for controlling antibiotic use in a tertiary-care paediatric hospital

The need to control antibiotic use has grown out of concern for costs and emerging resistance. The paediatric population poses some different opportunities and barriers for controlling antibiotic use. Several strategies to promote rational antibiotic use that have been introduced at The Hospital for Sick Children, Toronto, Ontario are presented. These include a formulary system, restricted drug program, therapeutic interchange program, sequential antibiotic therapy, automatic stop orders, antibiotic order forms, drug use evaluation program, guidelines for antibiotic use, standardized dosing, educational efforts, appropriate use of culture and sensitivity reporting, rational use of therapeutic drug monitoring and monitoring by pharmacists of antibiotic use.

Impact upon clinical outcomes of translation of PNA FISH-generated laboratory data from the clinical microbiology bench to bedside in real time

Fluorescence in situ hybridization using peptide nucleic acid probes (PNA-FISH) differentiates Staphylococcus aureus from other Gram-positive-cocci in clusters (GPCC). 101/202 patients with GPCC+ blood cultures were randomly assigned to clinician-notification of PNA FISH results. Notification was associated with reduced mortality (8% vs.17%, p = 0.05), further antibiotic use (median −2.5 days, p = 0.01), and trended toward reduced hospital stay and charges.

Effects of an operational multidisciplinary team on hospital antibiotic use and cost in France: a cluster controlled trial

OBJECTIVE

The study objective was to evaluate the effectiveness of an operational multidisciplinary antibiotic team, including an infectious disease physician and a clinical pharmacist, in reducing the hospital antimicrobial consumption and costs.

SETTING

The 1800-bed University Hospitals of Nancy (France).

METHOD

A cluster controlled 'before-after' study was performed. The intervention group comprised 11 medical and surgical wards in settings where the operational antibiotic team was implemented, and the control group comprised 6 wards without this operational team. The 'before' period (2005) preceded the implementation of the operational team in the intervention group and 'after' (July 2007 to June 2008) followed its full implementation.

MAIN OUTCOME MEASURE

We compared consumption of antibiotics overall and by therapeutic class (in defined daily doses per 1,000 patient days) and cost savings (in <euro>) between 'before' and 'after' in both groups (control and intervention), using a mixed effect linear model.

RESULTS

The overall consumption of antibiotics decreased after implementation of the operational team by 33.6% in the intervention group and by 3.3% in the control group (P = 0.003). Compared with the control group, the decrease in antibiotic use in the intervention group was significantly higher for various therapeutic classes (broad-spectrum penicillins, injectable fluoroquinolones, glycopeptides) and specific drugs (imipenem, ciprofloxacin, teicoplanin). For the same activity, the total cost savings were 14-fold higher in the intervention group.

CONCLUSION

Establishment of an operational multidisciplinary team may be an effective way to reduce hospital antibiotic use and cost, with a good acceptance rate among prescribers.

Covering more Territory to Fight Resistance: Considering Nurses' Role in Antimicrobial Stewardship

The potential contribution nurses can make to the management of antimicrobials within an in-patient setting could impact on the development of antimicrobial resistance (AMR) and healthcare associated infections (HCAIs). Current initiatives promoting prudent antimicrobial prescribing and management have generally failed to include nurses, which subsequently limits the extent to which these strategies can improve patient outcomes. For antimicrobial stewardship (AS) programmes to be successful, a sustained and seamless level of monitoring and decision making in relation to antimicrobial therapy is needed. As nurses have the most consistent presence as patient carer, they are in the ideal position to provide this level of service. However, for nurses to truly impact on AMR and HCAIs through increasing their profile in AS, barriers and facilitators to adopting this enhanced role must be contextualised in the implementation of any initiative.

49th ICAAC annual meeting: optimization of anti-infective use in the clinical setting

The meeting of the American Society of Microbiology was recently held in San Francisco, CA, USA - a gathering of experts in the fields of infectious diseases, microbiology and the pharmaceutical industry, among others. Owing to this large attendance and extensive coverage of many infectious disease topics, we focus on the optimization of anti-infective use in the clinical setting. We will cover antimicrobial stewardship, drugs with Gram-positive activity, and antifungal and antiretroviral agents.

Impact of an antimicrobial utilization program on antimicrobial use at a large teaching hospital: a randomized controlled trial

BACKGROUND

Multidisciplinary antimicrobial utilization teams (AUTs) have been proposed as a mechanism for improving antimicrobial use, but data on their efficacy remain limited.

OBJECTIVE

To determine the impact of an AUT on antimicrobial use at a teaching hospital.

DESIGN

Randomized controlled intervention trial.

SETTING

A 953-bed, public, university-affiliated, urban teaching hospital.

PATIENTS

Patients who were given selected antimicrobial agents (piperacillin-tazobactam, levofloxacin, or vancomycin) by internal medicine ward teams.

INTERVENTION

Twelve internal medicine teams were randomly assigned monthly: 6 teams to an intervention group (academic detailing by the AUT) and 6 teams to a control group that was given indication-based guidelines for prescription of broad-spectrum antimicrobials (standard of care), during a 10-month study period.

MEASUREMENTS

Proportion of appropriate empirical, definitive (therapeutic), and end (overall) antimicrobial usage.

RESULTS

A total of 784 new prescriptions of piperacillin-tazobactam, levofloxacin, and vancomycin were reviewed. The proportion of antimicrobial prescriptions written by the intervention teams that was considered to be appropriate was significantly higher than the proportion of antimicrobial prescriptions written by the control teams that was considered to be appropriate: 82% versus 73% for empirical (risk ratio [RR], 1.14; 95% confidence interval [CI], 1.04-1.24), 82% versus 43% for definitive (RR, 1.89; 95% CI, 1.53-2.33), and 94% versus 70% for end antimicrobial usage (RR, 1.34; 95% CI, 1.25-1.43). In multivariate analysis, teams that received feedback from the AUT alone (adjusted RR, 1.37; 95% CI, 1.27-1.48) or from both the AUT and the infectious diseases consultation service (adjusted RR, 2.28; 95% CI, 1.64-3.19) were significantly more likely to prescribe end antimicrobial usage appropriately, compared with control teams.

CONCLUSIONS

A multidisciplinary AUT that provides feedback to prescribing physicians was an effective method in improving antimicrobial use. Trial registration. ClinicalTrials.gov identifier: NCT00552838.

Pharmacoeconomic analysis of microbiologic techniques for differentiating staphylococci directly from blood culture bottles

Differentiating staphylococci in blood cultures is a critical issue, particularly when only one of two cultures is positive by Gram staining for staphylococci. New tests for the identification of Staphylococcus aureus allow faster results and definitive treatment compared to the tube coagulase test interpreted at 24 h (TCT24). These newer tests, peptide nucleic acid fluorescence in situ hybridization (PNA-FISH) and real-time PCR (RT-PCR), offer improved sensitivity at higher cost. Data suggest that the tube coagulase test may be interpreted at 4 h (TCT4) with little loss of sensitivity. The impact of variability in turnaround time, sensitivity, specificity, and cost on comparative cost-effectiveness is unknown. Our aim was to establish the cost-effectiveness of TCT24, PNA-FISH, RT-PCR, and TCT4 for direct identification of staphylococci in blood cultures. Decision analysis comparing these strategies was done from the institutional perspective. Besides test variables, other variables included patient risk factors, empirical treatment, and follow-up cultures. Probability and cost estimates came from the literature and institutional data. Base case estimates were derived from institutional rates of 73% contamination when coagulase-negative staphylococci were identified, 67.6% prevalence of risk factors, and 12.4% prevalence of S. aureus when one of two cultures yielded staphylococci. Sensitivity analysis was done across a range of probabilities and costs. In the base case, TCT4 and TCT24 were more cost-effective than RT-PCR and PNA-FISH ($78 versus $120 versus $165 per patient, respectively). The advantage of TCT4 and TCT24 remained robust upon sensitivity analysis. TCT4 should be further evaluated as a rapid, cost-effective means for identification of S. aureus in blood cultures.

Updated review of blood culture contamination

Blood culture contamination represents an ongoing source of frustration for clinicians and microbiologists alike. Ambiguous culture results often lead to diagnostic uncertainty in clinical management and are associated with increased health care costs due to unnecessary treatment and testing. A variety of strategies have been investigated and employed to decrease contamination rates. In addition, numerous approaches to increase our ability to distinguish between clinically significant bacteremia and contamination have been explored. In recent years, there has been an increase in the application of computer-based tools to support infection control activities as well as provide clinical decision support related to the management of infectious diseases. Finally, new approaches for estimating bacteremia risk which have the potential to decrease unnecessary blood culture utilization have been developed and evaluated. In this review, we provide an overview of blood culture contamination and describe the potential utility of a variety of approaches to improve both detection and prevention. While it is clear that progress is being made, fundamental challenges remain.

Guidelines for severe infections: are they useful?

PURPOSE OF REVIEW

The large variability in clinical practice plus the increasing awareness that certain processes of care are associated with improved medical outcomes has led to the development of clinical practice guidelines in serious infection. The evolution of guidelines and their impact on delivery of care in severe infection is reviewed.

RECENT FINDINGS

Guidelines development has centered around community- and hospital-acquired pneumonia as well as sepsis. The Institute of Healthcare Improvement has emerged as an international leader in changing healthcare professional behavior to be consistent with clinical recommendations in infection-related morbidity. These educational programs are designed to increase awareness of guidelines recommendations and to optimize their implementation. Change bundles are selected sets of interventions or processes distilled from evidence-based practice guidelines that are likely to improve outcome. As new evidence is published, and as experts ponder how the guidelines should best be expressed in the bundles, the bundles will be adapted to optimize their utility.

SUMMARY

The change bundle approach to performance improvement (guidelines-based) is the key to change in practice. The Surviving Sepsis Campaign/Institute of Healthcare Improvement sepsis change bundles are an excellent example of progress along these lines.

Adjustment of antibiotic treatment according to the results of blood cultures leads to decreased antibiotic use and costs

INTRODUCTION

To avoid the use of unnecessary broad-spectrum antibiotics, empirical therapy of bacteraemia should be adjusted according to the results of blood cultures.

OBJECTIVES

To investigate whether the results of blood cultures led to changes in antibiotic use and costs in a tertiary-care university hospital in Norway.

METHODS

Medical records from all patients with positive blood cultures in 2001 were analysed retrospectively. Factors predisposing to infections, results of blood cultures, antibiotic use and outcome were recorded. The influence of blood culture results on antibiotic treatment and costs were analysed.

RESULTS

The antibiotic use in 226 episodes of bacteraemia in 214 patients was analysed. According to the guidelines empirical antibiotic treatment should be adjusted in 166 episodes. Antibiotic use was adjusted in 146 (88%) of these 166 episodes, which led to a narrowing of therapy in 118 (80%) episodes. Compared with empirical therapy there was a 22% reduction in the number of antibiotics. Adjustment of therapy was more often performed in Gram-negative bacteraemia and polymicrobial cultures than in Gram-positive bacteraemia. In bacteraemia caused by ampicillin-resistant Escherichia coli, ampicillin was mostly replaced by ciprofloxacin. The cost for 7 days adjusted therapy in 146 episodes was euro19,800 (23%) less than for 7 days of empirical therapy.

CONCLUSIONS

Adjustment of antibiotic therapy according to the results of blood cultures led to a reduction in the number of antibiotics and a narrowing of antibiotic therapy. The costs for antibiotics decreased.

Risk factors for mortality resulting from bloodstream infections in a pediatric intensive care unit

BACKGROUND

Bloodstream infections (BSIs) are prevalent in the critical care setting and have high attributable morbidity and mortality. The purpose of this study was to identify factors that significantly contribute to immediate as well as eventual mortality in patients with bloodstream infections at a pediatric intensive care unit (PICU).

METHODS

Retrospective review of 2097 clinical records from admissions to our PICU in a 2-year period. Two separate case-control models were used. In the first model, eventual mortality (EM CASES) reflected those patients with eventual mortality, and EM CONTROLS were those who survived. In the second, infection-related mortality (IRM) cases were those with infection-related mortality, defined as death within 7 days of BSI, and IRM CONTROLS were survivors past 7 days. Logistic regression was used to adjust for differences for 3 categories: patient characteristics, microbiology and treatment variables.

RESULTS

We identified 74 separate episodes of bacteremia. Having an underlying malignancy or immunodeficiency was the only independently significant predictor of eventual mortality for BSI isolated within the PICU. Patients with infection-related mortality more likely had Gram-negative bacteremia and/or fungemia, were older and had inadequate initial empiric antibiotic treatment at the time BSI was diagnosed.

CONCLUSIONS

Targeted and aggressive early interventions should guide the empiric treatment of BSIs, whereas prolonged broad spectrum treatment should be minimized to avoid the emergence of resistant pathogen organisms.

Evaluation of antibiotic use in intensive care units of a tertiary care hospital in Turkey

The object of this study was to evaluate the appropriateness of antibiotic use in relation to diagnosis and bacteriological findings in the intensive care units (ICUs) of a 1100-bed referral and tertiary care hospital with an antibiotic restriction policy in Turkey. Between June and December 2002, patients who received antibiotics in the medical and surgical ICUs were evaluated prospectively. Two infectious diseases (ID) specialists assessed the antibiotics ordered daily. Of the 368 patients admitted to the ICUs, 223 (60.6%) received 440 antibiotics. The most frequently prescribed antibiotics were first-generation cephalosporins (16.1%), third-generation cephalosporins (15.2%), aminoglycosides (12.1%), carbapenems (10.7%) and ampicillin-sulbactam (8.7%). Antibiotic use was inappropriate in 47.3% of antibiotics. ID specialists recommended the use of 47% of all antibiotics. An antibiotic order without an ID consultation was more likely to be inappropriate [odds ratio (OR)=13.2, P<0.001, confidence intervals (CI)=4.4-39.5]. Antibiotics ordered empirically were found to be less appropriate than those ordered with evidence of culture and susceptibility results (OR=3.8, P=0.038, CI=1.1-13.1). Inappropriate antibiotic use was significantly higher in patients who had surgical interventions (OR=3.6, P=0.025, CI=1.2-10.8). Irrational antibiotic use was high for unrestricted antibiotics. In particular, antibiotic use was inappropriate in surgical ICUs. Additional interventions such as postgraduate training programmes and elaboration of local guidelines could be beneficial.

Clinical and Economic Analysis of Methicillin-Susceptible and -Resistant Staphylococcus aureus Infections

BACKGROUND:

The rate of methicillin-resistant Staphylococcus aureus (MRSA) has increased significantly over the last decade. Previous cohort studies of patients with MRSA bacteremia have reported higher mortality rates, increased morbidity, longer hospital length of stay (LOS), and higher costs compared with patients with methicillin-susceptible S. aureus (MSSA) bacteremia. The clinical and economic impact of MRSA involving other sites of infection has not been well characterized.

OBJECTIVE:

To determine the clinical and economic implications of MRSA compared with MSSA infections across a variety of infection sites and severity of illnesses.

METHODS:

A retrospective, case—control analysis comparing differences in clinical and economic outcomes of patients with MRSA and MSSA infections was conducted at an academic medical center. Case patients with MRSA infection were matched (1:1 ratio) to control patients with MSSA infection according to age, site of infection, and type of care.

RESULTS:

Thirty-six matched pairs of patients with S. aureus infection were identified. Baseline characteristics of patients with MSSA and MRSA infection were similar. Patients with MRSA infections had a trend toward longer hospital LOS (15.5 vs 11 days; p = 0.05) and longer antibiotic-related LOS (10 vs 7 days; p = 0.003). Median hospital cost associated with treatment of patients with MRSA infections was higher compared with patients with MSSA infections ($16 575 vs $12 862; p = 0.11); however, this difference was not statistically significant. Treatment failure was common in patients with MRSA infection. Among patients with MSSA infections, treatment failure was associated with vancomycin use.

CONCLUSIONS:

Patients with MRSA infections had worse clinical and economic outcomes compared with patients with MSSA infections.

Audit of an antibiotic policy and microbiological investigations for treating bacteraemia in a large teaching hospital

An audit of different approaches to guide empirical therapy in 78 cases of bacteraemia revealed poor utilisation of the antibiotic policy with resulting inadequate (P=0.005) or excessive (P<0.00001) antibiotic treatment and a trend to increased mortality. Eighty-seven percent of blood cultures were positive on Gram-stain within 24 h but streamlined therapy was still judged excessive in 27%. The results show poor utilisation of an up-to-date antibiotic policy but confirm its potential benefits and the ability of traditional culture methods to guide antibiotic therapy in a useful time-scale.

Inappropriate initial antimicrobial therapy and its effect on survival in a clinical trial of immunomodulating therapy for severe sepsis

PURPOSE

To examine the effect of inappropriate initial antimicrobial therapy on the prognosis of patients with sepsis who were enrolled in a clinical trial of an immunomodulating agent conducted in 108 hospitals in North America and Europe.

METHODS

We assessed initial antimicrobial choice and results of microbiologic cultures in 904 patients who had microbiologically confirmed severe sepsis or early septic shock. If a patient did not receive at least one antimicrobial agent to which the causative microorganisms were susceptible within 24 hours from the diagnosis of severe sepsis, then the initial antimicrobial treatment was considered to be inappropriate. A propensity score that adjusted for factors associated with inappropriate antimicrobial treatment was calculated and included in multivariable models to adjust for confounding.

RESULTS

A total of 468 patients (52%) had documented bloodstream infection, and 211 patients (23%) received inappropriate initial antimicrobial therapy. Characteristics associated with inappropriate treatment were study enrollment in Europe, admission to surgery, nosocomial infection, infection with multiresistant microorganisms, and fungal or polymicrobial infection (all P <0.05). The 28-day mortality was 24% (168/693) for patients in the adequately treated group versus 39% (82/211) for patients receiving inappropriate initial antimicrobial therapy (P <0.001). After adjusting for comorbid conditions, severity of illness, site of infection, and the propensity score, inappropriate antimicrobial therapy was independently associated with increased mortality (odds ratio = 1.8; 95% confidence interval: 1.2 to 2.6).

CONCLUSION

In a large cohort of patients with microbiologically confirmed severe sepsis, appropriate initial antimicrobial therapy was an important determinant of survival. New approaches aimed at improving detection and treatment of early sepsis are needed.

Evaluation of antibiotic use in a hospital with an antibiotic restriction policy

The study was designed to evaluate rational antibiotic use in relation to diagnosis and bacteriological findings. All hospitalized patients who received antibiotics were evaluated by a cross-sectional study. Of the 713 patients hospitalized, 281 (39.4%) patients received 377 antibiotics. Among 30 different antibiotics the most frequently requested were first generation cephalosporins (19.9%), ampicillin-sulbactam (19.1%) and aminoglycosides (11.7%). Antibiotic use was appropriate in 64.2% of antibiotic requests. In analysis of appropriate use, a request after an infectious diseases consultation was a frequent reason (OR=14, P<0.001, CI=0.02-0.24). Antibiotics requested in conjunction with susceptibility results were found to be more appropriate than those ordered empirically (OR=4.5, P=0.017, CI=0.06-0.76). Inappropriate antibiotic use was significantly higher among unrestricted antibiotics than restricted ones (P<0.001). Irrational antibiotic use was high for unrestricted antibiotics. Additional interventions such as postgraduate training programmes and elaboration of local guidelines could be beneficial.

A prospective comparison of antibiotic usage in pediatric surgical patients: the safety, advantage, and effectiveness of the Surgical Infection Society guidelines versus a common practice

BACKGROUND

The Surgical Infection Society (SIS) guidelines for antibiotic (Ab) usage minimally changed the surgical practice. The authors believed that clinical evidence of the safety, advantage, and effectiveness of SIS guidelines may improve inappropriate usage of Ab.

METHODS

A group of dedicated surgeons attempted to use Ab appropriately to SIS guidelines in their patients (group A). A comparison was made with a concurrent cohort of patients (group B), treated by surgeons who were nonsupporters of SIS guidelines. The trial was conducted in 378 children between March 1999 and May 2000. The outcome measures were morbidity and mortality rates, Ab treatment duration, timing of administration, unjustified spectrum, and switch of Ab. Analysis of variance and Chi2 test were used in statistics. P value less than.05 was considered significant (s).

RESULTS

Group A included 124 patients and Group B, 254. There were no intergroup differences in age, sex, and clean/contaminated/dirty ratio of procedures. The mean duration of Ab treatment was 3.9 days in group A, versus 7.1 days in group B (s), with overall rate of appropriateness of 77% versus 36% (s) and no differences in mortality and morbidity rates.

CONCLUSION

Perhaps these results may change Ab usage in pediatric surgery.

Blood culturing practices in a trauma intensive care unit: does concurrent antibiotic use make a difference?

BACKGROUND

Febrile trauma patients have repeated blood cultures drawn during a prolonged hospitalization. We examined the diagnostic yield of blood cultures in severely injured patients to determine whether concurrent antimicrobial therapy or prophylactic administration of antibiotics affects blood culture growth. We also determined how rapidly growth changed to determine whether total numbers of blood cultures could be decreased. The hypotheses of the study were that concurrent antimicrobial administration affects blood culture yield, prophylactic administration alters the culture result, and repetitive culturing is unnecessary.

METHODS

A retrospective chart review of trauma patients with minimum Injury Severity Score of 15 and minimum 5-day intensive care unit length of stay was performed. The dates and results of blood cultures and antibiotic type and administration dates were recorded. "Prophylactic" antibiotics were defined as antibiotics administered on admission to the unit. Computer software was used to match the blood culture date to the period of antimicrobial administration. Categorical data were compared using Fisher's exact test.

RESULTS

Two hundred fifty-eight patients met entry criteria, and 208 charts were complete for review. One hundred twenty-nine patients had 347 sets of blood cultures drawn. The positive blood culture rate was 10.8% in patients off antibiotics, and 13.9% in patients on antibiotics (p = 0.68). All prophylactic antibiotics included a beta-lactam. Only 18% of positive blood cultures in patients receiving prophylactic antibiotics were sensitive to beta-lactams as opposed to 59% sensitivity in those who did not receive prophylaxis (p = 0.03). One hundred seventy-six sets of blood cultures were performed after an initial positive culture. Only three patients with an initial positive culture had a second positive culture with a different organism. The mean time to culturing a new organism after initial growth was 19 days.

CONCLUSION

Concurrent antimicrobial administration does not alter blood culture yield. Prophylactic administration alters the type of organism cultured. Little new information is gained from repetitive culturing.

Nosocomial infections and misuse of antibiotics in a provincial community hospital, Saudi Arabia

The incidence of nosocomial infection and prevalence of antibiotic misuse were studied in a 174-bed community hospital in Saudi Arabia over a six-month period. Of 2445 patients admitted, 8.5% developed nosocomial infection, the rates were highest for nursery (35.8%), intensive care (19.8%), gynaecological (16.2%) and surgical (11.7%) patients. Urinary tract (31.3%), wound (27.1%) and blood (14.9%) infections accounted for more than 70% of the infections. Staphylococcus aureus (23%) and Pseudomonas aeruginosa (11%), caused more than 90% of the infections. The majority of the bacterial pathogens (79%) were multi-drug resistant. Over 80% of patients were administered prophylactic and/or therapeutic antibiotics, with 53% receiving multiple antibiotics; 72% of the antibiotics were judged to be misused. Both prophylaxis and treatment were mostly misguided and clinically unwarranted. Host- and hospital-associated infection risk factors were identified. The minimum government cost estimates for the nosocomial infections and misused antibiotics were US $273 180 and $565 603, respectively. The findings emphasize the need for effective measures to reduce both the high infection rates and widespread antibiotic misusage in the hospital. Such measures should include institution of an effective infection control committee and a hospital antibiotic policy.

Endemic nosocomial infections and misuse of antibiotics in a maternity hospital in Saudi Arabia

Patients admitted during a 6-month period to a maternity hospital in Saudi Arabia were studied for nosocomial infections and misuse of antibiotics. Patient history and diagnosis on admission and subsequent clinical and laboratory data were analysed. Infection developing from 72 h after admission was considered nosocomial. Therapeutic and prophylactic data as recorded on the patients' charts were assessed for possible misuse of antibiotics. Of 3439 patients, 136 (4.0%) developed nosocomial infection: 2.0%, 8.9% and 37.7% in obstetric, gynaecologic and nursery patients, respectively. Infections among adults were mostly found in the urinary (44.4%) and lower genital (33.3%) tracts. Among newborns, over 70% of cases were eye and ear (29.8%), skin (26.2%) and blood (19.0%) infections. Gram-negative bacteria caused 65.7% of the infections. Over 90% of the bacterial isolates were multidrug-resistant. About 24% of patients received single or multiple antibiotics; 57.2% were misused. The minimal hospital cost estimate for both nosocomial infections and misused antibiotics was US $318,705. The findings of this study, the first of its type in this region, should prompt improved infection control measures as well as educational and antibiotic restriction interventions.

Influence of an infectious disease consulting service on quality and costs of antibiotic prescriptions in a university hospital

An infectious disease consulting service was set up at a large tertiary university hospital in 1996 to evaluate and to improve antibiotic prescription patterns. Treatment guidelines for the most common bacterial infections were implemented. On daily ward rounds antibiotic therapies without evidence of an infectious disease were stopped and inappropriate regimens were changed by an infectious disease specialist. During a 6-month prospective intervention period, 3,528 patients were studied on 13 wards of the department of internal medicine; 513 of these patients (14.5%) received antibiotic therapy. These treatment courses were evaluated as adequate in 394 cases (76.8%) and incorrect in 119 cases (23.2%). Inadequate antibiotic substances were chosen in 72 out of 119 cases (60.5%) and there was no indication for treatment in 38 out of 119 cases (32%). Pathogen-specific therapies were inadequate significantly more often than empirical antimicrobial therapies (p < 0.001). In addition, the duration of the perioperative prophylaxis could be limited to 1 d. Comparing the intervention period with a 3-month control interval without an infectious disease consulting service, a total of 31,510 Euro (including the costs for the infectious disease specialist) could be saved. No increase in infection-related mortality or length of stay was observed. These data show that an infectious disease consulting service optimizes antibiotic usage, and is cost-effective as a result of a significant cost reduction in hospitals, while not interfering with the quality of medical care.

Polymerase Chain Reaction for the Detection of Bacteremia

Analysis of blood by polymerase chain reaction (PCR) is a more rapid and sensitive method to detect bacteremia than blood culture. The PCR was performed on blood obtained from patients during blood culture draws and on blood from normal volunteers. Eighty-seven patients provided 125 blood samples for blood culture comparison with PCR. Specific PCR primers for Staphylococcus aureus and Escherichia coli that targeted conserved regions common to Gram-positive and Gram-negative bacteria were used. Selective stringency conditions identified other Gram-positive and Gram-negative bacteria. The blood culture agreed with the PCR in 93 of the 125 patient specimens (74%). In 29 of these specimens the PCR was positive yet the blood culture was negative. When clinical information was included with positive blood culture to define sepsis in these patients and their specimens were added to the positive blood cultures the statistical accuracy of PCR was 93 per cent. Only three of the 78 specimens with negative PCR had positive blood cultures. The PCR was negative in all but one of the 50 volunteers. PCR is more sensitive than blood culture, and it can quickly rule out bacteremia.

Do guidelines for community-acquired pneumonia improve the cost-effectiveness of hospital care?

There is growing pressure to demonstrate the value of practice guidelines. We have reviewed the evidence that guidelines for the treatment of community-acquired pneumonia (CAP) change current practices and that the standardization of practices reduces costs and/or improves outcome. The most obvious barrier to implementation of the guidelines is lack of knowledge about their content; equally important are the attitudes and behavior of professionals, patients, and their caregivers. Guidelines may improve the outcome of CAP, provided that there is an association between variations in outcome and some specific processes of care. Conversely, when there is no such relationship, guidelines may reduce the cost of care without having an adverse effect on outcome. The cost-effectiveness of CAP guidelines in an individual hospital depends on the systems that are available to identify patients with CAP and to measure the processes of care. There is good evidence that following the recommendations of the CAP guidelines does improve the cost-effectiveness of care and, therefore, that an audit of CAP may be worth the effort.