Practice patterns for antibiotic de-escalation in culture-negative healthcare-associated pneumonia

The impact of antimicrobial de-escalation therapy in culture-negative pneumonia: a systematic review and meta-analysis

BACKGROUND/AIMS

Antimicrobial de-escalation (ADE) remains a challenging strategy in the treatment of pneumonia. We investigated the outcomes of ADE as measured by mortality and duration of the use of antibiotics in patients with culture- negative pneumonia.

METHODS

We performed a systematic review and meta-analysis in accordance with PRISMA guidelines. The primary outcome was inpatient mortality.

RESULTS

We examined six studies comprising 11,933 subjects, of whom 1,152 received ADE. Overall, the ADE strategy was associated with a statistically lower risk of in-hospital mortality compared with non-ADE (risk ratio [RR] = 0.60, 95% confidence interval [CI] = 0.38 to 0.93). Although substantial heterogeneity was found among the included studies (I2 = 66%), a meta-regression analysis could not reveal plausible sources of heterogeneity. And ADE was associated with a shorter duration of total and initial antibiotic therapies and total length of hospital stay compared with non-ADE.

CONCLUSION

Our findings suggest that ADE seems to be significantly associated with better clinical outcomes compared with non-ADE. Caution is demanded when interpreting data of this study because of substantial between-study heterogeneity.

De-escalation of Empiric Antibiotics Following Negative Cultures in Hospitalized Patients With Pneumonia: Rates and Outcomes

BACKGROUND

For patients at risk for multidrug-resistant organisms, IDSA/ATS guidelines recommend empiric therapy against methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas. Following negative cultures, the guidelines recommend antimicrobial de-escalation. We assessed antibiotic de-escalation practices across hospitals and their associations with outcomes in hospitalized patients with pneumonia with negative cultures.

METHODS

We included adults admitted with pneumonia in 2010-2015 to 164 US hospitals if they had negative blood and/or respiratory cultures and received both anti-MRSA and antipseudomonal agents other than quinolones. De-escalation was defined as stopping both empiric drugs on day 4 while continuing another antibiotic. Patients were propensity adjusted for de-escalation and compared on in-hospital 14-day mortality, late deterioration (ICU transfer), length-of-stay (LOS), and costs. We also compared adjusted outcomes across hospital de-escalation rate quartiles.

RESULTS

Of 14 170 patients, 1924 (13%) had both initial empiric drugs stopped by hospital day 4. Hospital de-escalation rates ranged from 2-35% and hospital de-escalation rate quartile was not significantly associated with outcomes. At hospitals in the top quartile of de-escalation, even among patients at lowest risk for mortality, the de-escalation rates were <50%. In propensity-adjusted analysis, patients with de-escalation had lower odds of subsequent transfer to ICU (adjusted odds ratio, .38; 95% CI, .18-.79), LOS (adjusted ratio of means, .76; .75-.78), and costs (.74; .72-.76).

CONCLUSIONS

A minority of eligible patients with pneumonia had antibiotics de-escalated by hospital day 4 following negative cultures and de-escalation rates varied widely between hospitals. To adhere to recent guidelines will require substantial changes in practice.

Time to First Culture Positivity for Gram-Negative Rods Resistant to Ceftriaxone in Critically Ill Adults

BACKGROUND

The optimal timing for the de-escalation of broad-spectrum antibiotics with activity against Pseudomonas aeruginosa and resistant Gram-negative rods (GNRs) in critically ill adults remains unknown.

RESEARCH QUESTION

We tested the hypothesis that cultures will identify GNRs that ultimately demonstrate resistance to ceftriaxone within 48 hours, potentially allowing safe de-escalation at this time point.

STUDY DESIGN AND METHODS

We conducted a secondary analysis of data from the Isotonic Solutions and Major Adverse Renal Events Trial: a pragmatic, cluster-randomized, multiple-crossover trial comparing balanced crystalloids versus saline for intravenous fluid administration in 15,802 critically ill adults at 5 intensive care units (ICUs) at Vanderbilt University Medical Center in Nashville, TN, USA. The primary endpoint was the time-to-positivity of respiratory and blood cultures that ultimately demonstrated growth of GNRs resistant to ceftriaxone. Multivariable logistic regression modeling was used to examine risk factors for the growth of cultures after 48 hours.

RESULTS

A total of 524 respiratory cultures had growth of GNRs, of which 284 (54.2%) had resistance to ceftriaxone. A total of 376 blood cultures grew GNRs, of which 70 (18.6%) had resistance to ceftriaxone. At 48 hours, 87% of respiratory cultures and 85% of blood cultures that ultimately grew GNRs resistant to ceftriaxone had demonstrated growth. Age, gender, predicted risk of inpatient mortality and prior use of antibiotics did not predict the growth of cultures after 48 hours.

INTERPRETATION

Among a cohort of critically ill adults, 13% of respiratory cultures and 15% of blood cultures that ultimately grew GNRs resistant to ceftriaxone did not demonstrate growth until at least 48 hours after collection. Further work is needed to determine the ideal time for critically ill adults to de-escalate from broad-spectrum antibiotics targeting Pseudomonas aeruginosa and extended-spectrum β-lactamase-producing gram-negative pathogens.

Impact of antimicrobial de-escalation on mortality: a literature review of study methodology and recommendations for observational studies

Introduction: The safety of de-escalation of empirical antimicrobial therapy is largely based on observational data, with many reporting protective effects on mortality. As there is no plausible biological explanation for this phenomenon, it is most probably caused by confounding by indication.Areas covered: We evaluate the methodology used in observational studies on the effects of de-escalation of antimicrobial therapy on mortality. We extended the search for a recent systematic review and identified 52 observational studies. The heterogeneity in study populations was large. Only 19 (36.5%) studies adjusted for confounders and four (8%) adjusted for clinical stability during admission, all as a fixed variable. All studies had methodological limitations, most importantly the lack of adjustment for clinical stability, causing bias toward a protective effect.Expert opinion: The methodology used in studies evaluating the effects of de-escalation on mortality requires improvement. We depicted all potential confounders in a directed acyclic graph to illustrate all associations between exposure (de-escalation) and outcome (mortality). Clinical stability is an important confounder in this association and should be modeled as a time-varying variable. We recommend to include de-escalation as time-varying exposure and use inverse-probability-of-treatment weighted marginal structural models to properly adjust for time-varying confounders.

Predictors of Treatment Failure Following De-escalation to a Fluoroquinolone in Culture-Negative Nosocomial Pneumonia

Background: Little evidence exists for de-escalation of nosocomial pneumonia therapy without positive cultures. Objective: The purpose of this study was to identify potential predictors of treatment failure following de-escalation to a fluoroquinolone in culture-negative nosocomial pneumonia. Methods: The study involved a single-center, retrospective cohort of patients admitted with diagnosis of nosocomial pneumonia and positive chest radiography who received at least 24 hours of fluoroquinolone monotherapy following at least 24 hours of appropriate empirical antibiotics. Treatment failure was defined using a composite of all-cause death within 30 days of discharge, treatment re-escalation, or readmission for pneumonia within 30 days of discharge. The Cox proportional hazards model was used to analyze predictors of treatment failure. Duration of empirical antibiotics and significant univariable exploratory predictors were included in multivariable analysis. Results: Of 164 patients, 23 (14%) failed de-escalation. Duration of empirical antibiotics (68.5 ± 32.1 vs 65.8 ± 35 hours) was not associated with treatment failure in univariable (Hazard Ratio [HR] = 1.002 [95% CI = 0.991-1.013]) or multivariable analyses (HR = 1.003 [95% CI = 0.991-1.015]). Significant exploratory predictors on univariable analysis included active cancer, intensive care unit (ICU) admission at empirical initiation, APACHE II score, and steroid use ≥20-mg prednisone equivalent. ICU admission at empirical initiation (HR = 2.439 [95% CI = 1.048-5.676]) and steroid use ≥20-mg prednisone equivalent (HR = 2.946 [95% CI = 1.281-6.772]) were associated with treatment failure on multivariable analysis. Conclusion and Relevance: Duration of empirical antibiotics does not appear to influence failure of de-escalation to fluoroquinolone monotherapy in culture-negative nosocomial pneumonia.

Pharmacist recommendations for carbapenem de-escalation in urinary tract infection within an antimicrobial stewardship program

BACKGROUND

Carbapenem antibiotics are considered the treatment of choice for serious extended-spectrum beta-lactamase-producing Gram-negative bacteria infections. Our objectives were to analyze the results of carbapenem de-escalation therapy in complicated urinary tract infections (UTIs) attended in a third-level Spanish hospital and to evaluate the impact of pharmacist recommendation in this practice, the outcomes obtained, and associated factors.

METHODS

This prospective observational study of carbapenem prescriptions and de-escalation performance was conducted in a third-level hospital between August 1 2013 and July 31, 2014. Data were gathered on carbapenem treatment duration, de-escalation, length of hospital stay, mortality rate, and associated re-admissions.

RESULTS

De-escalation, which was only ordered for patients with positive cultures, was conducted in 49.7% of the 163 patients with complicated UTI. More than half (69.1%) of pharmacist interventions were accepted. De-escalation reduced the median hospital stay by five days (p=0.030). Crude hospital mortality was lower in the de-escalation group (7.4% vs. 29.3%, p<0.001), although their exposure to carbapenems was lower (4 vs 6 days, p<0.001). Factors associated with de-escalation were ICU stay for at least 48h, pharmacist recommendation and ESBL or AmpC producing Enterobacteriaceae. Factors associated with in-hospital mortality were age, previous admission and duration of hospital stay, but not pharmacist recommendation. Otherwise, carbapenem de-escalation was associated as a protective factor against in-hospital mortality.

CONCLUSIONS

Carbapenem de-escalation in accordance with pharmacist recommendation proved to be a safe approach in complicated UTI, reducing the hospital stay of patients without affecting the re-admission rate.

Health Care-Associated Pneumonia: Is It Still a Useful Concept?

"Health care-associated pneumonia (HCAP) was introduced into guidelines because of concerns about the increasing prevalence of drug-resistant pathogens (DRPs) not covered by standard empirical therapy. We now know that DRPs are very localized phenomena with low rates in most sites. Although HCAP risk factors are associated with a higher mortality, this is driven by comorbidities rather than the pathogens. Empirical coverage of DRPs has generally not resulted in better patient outcomes. A far more nuanced approach must be taken for patients with risk factors for DRPs taking into account the local cause and severity of disease.

The Lung Microbiome and Its Role in Pneumonia

The use of next-generation sequencing and multiomic analysis reveals new insights on the identity of microbes in the lower airways blurring the lines between commensals and pathogens. Microbes are not found in isolation; rather they form complex metacommunities where microbe-host and microbe-microbe interactions play important roles on the host susceptibility to pathogens. In addition, the lower airway microbiota exert significant effects on host immune tone. Thus, this review highlights the roles that microbes in the respiratory tract play in the development of pneumonia.

Clinical outcomes of carbapenem de-escalation regardless of microbiological results: A propensity score analysis

OBJECTIVE

The aim of this study was to evaluate the safety and efficacy of de-escalation in patients under treatment with carbapenems and its impact on clinical outcomes.

METHODS

A prospective observational study was conducted for 1year. Patients administered active carbapenems for at least 24h were included. Primary outcomes were in-hospital mortality, mortality at 30 days after carbapenem prescription, and infection-related readmission within 30 days. De-escalation was defined as the substitution of carbapenem with narrower spectrum antimicrobial agents or its discontinuation during the first 96h of treatment.

RESULTS

The study included 1161 patients, and de-escalation was performed in 667 (57.5%) of these. In the de-escalation group, 54.9% of cultures were positive. After propensity score matching, 30-day mortality was lower (17.4% vs. 25.7%, p=0.036), carbapenem treatment was 4 days shorter (4 vs. 8 days, p<0.001), total antibiotic therapy duration was 2 days longer (12 vs. 10 days, p=0.003), and length of hospital stay was 5 days shorter (8 vs. 13 days, p=0.008) in the de-escalated versus non-de-escalated patients. In-hospital mortality and 30-day readmission rates did not differ significantly between these groups.

CONCLUSION

Carbapenem de-escalation is a safe strategy that does not compromise the clinical status of patients.

The Daniel K. Inouye College of Pharmacy Scripts: The Effects of Vancomycin Use and De-escalation in Patients Hospitalized with Pneumonia

Methicillin-resistant Staphylococcus aureus (MRSA) causes about 80,000 severe infections each year. Compared to Methicillin-susceptible Staphylococcus aureus (MSSA), MRSA is associated with higher mortality and increased hospital length of stay (LOS). Vancomycin hydrochloride, an antibiotic with activity against MRSA is often used as empiric therapy for pneumonia. However, current pneumonia treatment guidelines recommend against the routine use of MRSA coverage since MRSA prevalence rates are low. In this retrospective, observational study, 38.3% of the population received vancomycin while only 2.6% had evidence of a MRSA infection. Data was gathered manually from electronic medical records from four hospitals over a six-month period. To identify a well-balanced comparison and account for potential confounders, matching on the propensity scores was conducted. Prior to matching, those who received vancomycin had a significantly higher rate of mortality (14.3% vs 4.9%, P < .001) and higher LOS (9.6 days vs 7.2 days, P < .001). Those who were de-escalated from vancomycin had a significantly lower LOS (8.3 days vs 11.6 days, P = .001) with no difference in mortality. After performing a survival analysis on matching data, those who received vancomycin had a significantly higher LOS (9.2 days vs 7.5 days, P = .002) with no difference in mortality (P = .1737). Those who were de-escalated had a significantly lower LOS (8.3 days vs 11.3 days, P=.005) with no difference in mortality (P = .8624). This study demonstrates a low prevalence of MRSA with the potential overuse of vancomycin. This along with no difference in mortality and a lower LOS supports the recommendation to limit vancomycin use as clinically appropriate. If vancomycin is used, assessment for rapid de-escalation is needed.

Physicians' utilization of microbiologic reports and determinants of their preference to order culture in Tikur Anbessa Specialized Hospital, Addis Ababa, Ethiopia

Objective

The main aim of the study was to assess physicians’ utilization of microbiologic reports and determinants of their preference in ordering microbiologic culture among patients with systemic bacterial infection at Tikur Anbessa Specialized Hospital.

Results

Of the total 369 patients observed, 91 (24.7%) had microbiologic reports (culture and gram stain). About 12% of the patients had culture reports of which majority (77.8%) were available after 72 h of the initial antibiotic start. Antimicrobial susceptibility test was done for 83.3% of the positive cultures. Although 99.5% of the patients were initially placed on empiric therapy, adjustment was done in 114 (30.9%) of the patients. Among these patients with adjusted therapy, changes were unrelated to microbiologic reasons in 103 (90.4%) patients. None of these changes were for the reason of streamlining therapy. Prolonged hospital stay (AOR = 2.9, 95% CI 1.2–6.7), senior physician consultation (AOR = 4.1, 95% CI 1.1–17.7) and suspicion of new site of infection (AOR = 2.6, 95% CI 1.1–6.2) were positive independent predictors for physicians’ preference in ordering culture.

Electronic supplementary material

The online version of this article (10.1186/s13104-018-3782-y) contains supplementary material, which is available to authorized users.

Broad- versus Narrow-Spectrum Oral Antibiotic Transition and Outcomes in Health Care-associated Pneumonia

RATIONALE

Guidelines recommend a switch from intravenous to oral antibiotics once patients who are hospitalized with pneumonia achieve clinical stability. However, little evidence guides the selection of an oral antibiotic for patients with health care-associated pneumonia, especially where no microbiological diagnosis is made.

OBJECTIVES

To compare outcomes between patients who were transitioned to broad- versus narrow-spectrum oral antibiotics after initially receiving broad-spectrum intravenous antibiotic coverage.

METHODS

We performed a secondary analysis of an existing database of adults with community-onset pneumonia admitted to seven Utah hospitals. We identified 220 inpatients with microbiology-negative health care-associated pneumonia from 2010 to 2012. After excluding inpatient deaths and treatment failures, 173 patients remained in which broad-spectrum intravenous antibiotics were transitioned to an oral regimen. We classified oral regimens as broad-spectrum (fluoroquinolone) versus narrow-spectrum (usually a β-lactam). We compared demographic and clinical characteristics between groups. Using a multivariable regression model, we adjusted outcomes by severity (electronically calculated CURB-65), comorbidity (Charlson Index), time to clinical stability, and length of intravenous therapy.

MEASUREMENTS AND MAIN RESULTS

Age, severity, comorbidity, length of intravenous therapy, and clinical response were similar between the two groups. Observed 30-day readmission (11.9 vs. 21.4%; P = 0.26) and 30-day all-cause mortality (2.3 vs. 5.3%; P = 0.68) were also similar between the narrow and broad oral antibiotic groups. In multivariable analysis, we found no statistically significant differences for adjusted odds of 30-day readmission (adjusted odds ratio, 0.56; 95% confidence interval, 0.06-5.2; P = 0.61) or 30-day all-cause mortality (adjusted odds ratio, 0.55; 95% confidence interval, 0.19-1.6; P = 0.26) between narrow and broad oral antibiotic groups.

CONCLUSIONS

On the basis of analysis of a limited number of patients observed retrospectively, our findings suggest that it may be safe to switch from broad-spectrum intravenous antibiotic coverage to a narrow-spectrum oral antibiotic once clinical stability is achieved for hospitalized patients with health care-associated pneumonia when no microbiological diagnosis is made. A larger retrospective study with propensity matching or regression-adjusted test of equivalence or ideally a prospective comparative effectiveness study will be necessary to confirm our observations.

Assessment of the multiplex PCR-based assay Unyvero pneumonia application for detection of bacterial pathogens and antibiotic resistance genes in children and neonates

BACKGROUND

Pneumonia is a major healthcare problem. Rapid pathogen identification is critical, but often delayed due to the duration of culturing. Early, broad antibacterial therapy might lead to false-negative culture findings and eventually to the development of antibiotic resistances. We aimed to assess the accuracy of the new application Unyvero P50 based on multiplex PCR to detect bacterial pathogens in respiratory specimens from children and neonates.

METHODS

In this prospective study, bronchoalveolar lavage fluids, tracheal aspirates, or pleural fluids from neonates and children were analyzed by both traditional culture methods and Unyvero multiplex PCR.

RESULTS

We analyzed specimens from 79 patients with a median age of 1.8 (range 0.01-20.1). Overall, Unyvero yielded a sensitivity of 73.1% and a specificity of 97.9% compared to culture methods. Best results were observed for non-fermenting bacteria, for which sensitivity of Unyvero was 90% and specificity 97.3%, while rates were lower for Gram-positive bacteria (46.2 and 93.9%, respectively). For resistance genes, we observed a concordance with antibiogram of 75% for those specimens in which there was a cultural correlate.

CONCLUSIONS

Unyvero is a fast and easy-to-use tool that might provide additional information for clinical decision making, especially in neonates and in the setting of nosocomial pneumonia. Sensitivity of the PCR for Gram-positive bacteria and important resistance genes must be improved before this application can be widely recommended.

Strategies to enhance rational use of antibiotics in hospital: a guideline by the German Society for Infectious Diseases

Introduction

In the time of increasing resistance and paucity of new drug development there is a growing need for strategies to enhance rational use of antibiotics in German and Austrian hospitals. An evidence-based guideline on recommendations for implementation of antibiotic stewardship (ABS) programmes was developed by the German Society for Infectious Diseases in association with the following societies, associations and institutions: German Society of Hospital Pharmacists, German Society for Hygiene and Microbiology, Paul Ehrlich Society for Chemotherapy, The Austrian Association of Hospital Pharmacists, Austrian Society for Infectious Diseases and Tropical Medicine, Austrian Society for Antimicrobial Chemotherapy, Robert Koch Institute.

Materials and methods

A structured literature research was performed in the databases EMBASE, BIOSIS, MEDLINE and The Cochrane Library from January 2006 to November 2010 with an update to April 2012 (MEDLINE and The Cochrane Library). The grading of recommendations in relation to their evidence is according to the AWMF Guidance Manual and Rules for Guideline Development.

Conclusion

The guideline provides the grounds for rational use of antibiotics in hospital to counteract antimicrobial resistance and to improve the quality of care of patients with infections by maximising clinical outcomes while minimising toxicity. Requirements for a successful implementation of ABS programmes as well as core and supplemental ABS strategies are outlined. The German version of the guideline was published by the German Association of the Scientific Medical Societies (AWMF) in December 2013.

Empiric Antibiotic Therapy of Nosocomial Bacterial Infections

Broad-spectrum antibiotics are commonly used by physicians to treat various infections. The source of infection and causative organisms are not always apparent during the initial evaluation of the patient, and antibiotics are often given empirically to patients with suspected sepsis. Fear of attempting cephalosporins and carbapenems in penicillin-allergic septic patients may result in significant decrease in the spectrum of antimicrobial coverage. Empiric antibiotic therapy should sufficiently cover all the suspected pathogens, guided by the bacteriologic susceptibilities of the medical center. It is important to understand the major pharmacokinetic properties of antibacterial agents for proper use and to minimize the development of resistance. In several septic patients, negative cultures do not exclude active infection and positive cultures may not represent the actual infection. This article will review the important differences in the spectrum of commonly used antibiotics for nosocomial bacterial infections with a particular emphasis on culture-negative sepsis and colonization.

Frequency of empiric antibiotic de-escalation in an acute care hospital with an established Antimicrobial Stewardship Program

BACKGROUND

Expanding antimicrobial resistance patterns in the face of stagnant growth in novel antibiotic production underscores the importance of antibiotic stewardship in which de-escalation remains an integral component. We measured the frequency of antibiotic de-escalation in a tertiary care medical center with an established antimicrobial stewardship program to provide a plausible benchmark for de-escalation.

METHODS

A retrospective, observational study was performed by review of randomly selected electronic medical records of 240 patients who received simultaneous piperacillin/tazobactam and vancomycin from January to December 2011 at an 885-bed tertiary care medical center. Patient characteristics including antibiotic regimen, duration and indication, culture results, length of stay, and hospital mortality were evaluated. Antibiotic de-escalation was defined as the use of narrower spectrum antibiotics or the discontinuation of antibiotics after initiation of piperacillin/tazobactam and vancomycin therapy. Subjects dying within 72 h of antibiotic initiation were considered not de-escalated for subsequent analysis and were subtracted from the study population in determining a modified mortality rate.

RESULTS

The most commonly documented indications for piperacillin/tazobactam and vancomycin therapy were pneumonia and sepsis. Of the 240 patients studied, 151 (63%) had their antibiotic regimens de-escalated by 72 h. The proportion of patients de-escalated by 96 h with positive vs. negative cultures was similar, 71 and 72%, respectively. Median length of stay was 4 days shorter in de-escalated patients, and the difference in adjusted mortality was not significant (p = 0.82).

CONCLUSIONS

The empiric antibiotic regimens of approximately two-thirds of patients were de-escalated by 72 h in an institution with a well-established antimicrobial stewardship program. While this study provides one plausible benchmark for antibiotic de-escalation, further studies, including evaluations of antibiotic appropriateness and patient outcomes, are needed to inform decisions on potential benchmarks for antibiotic de-escalation.

Health care-associated pneumonia in the intensive care unit: Guideline-concordant antibiotics and outcomes

PURPOSE

Recent data have not demonstrated improved outcomes when guideline-concordant (GC) antibiotics are given to patients with health care-associated pneumonia (HCAP). This study was designed to evaluate the relationship between health outcomes and GC therapy in patients admitted to an intensive care unit (ICU) with HCAP.

MATERIALS AND METHODS

We performed a population-based cohort study of patients admitted to greater than 150 hospitals in the US Veterans Health Administration system to compare baseline characteristics, bacterial pathogens, and health outcomes in ICU patients with HCAP receiving GC-HCAP therapy, GC community-acquired pneumonia (GC-CAP) therapy, or non-GC therapy. The primary outcome was 30-day patient mortality. Risk factors for the primary outcome were assessed in a multivariable logistic regression model.

RESULTS

A total of 3593 patients met inclusion criteria and received GC-HCAP therapy (26%), GC-CAP therapy (23%), or non-GC therapy (51%). Patients receiving GC-HCAP had higher 30-day patient mortality compared to GC-CAP patients (34% vs 22%; P< .0001). After controlling for confounders, risk factors for 30-day patient mortality were vasopressor use (odds ratio, 1.67; 95% confidence interval, 1.30-2.13), recent hospital admission (1.53; 1.15-2.02), and receipt of GC-HCAP therapy (1.51; 1.20-1.90).

CONCLUSIONS

Our data do not demonstrate improved outcomes among ICU patients with HCAP who received GC-HCAP therapy.

Antimicrobial de-escalation of treatment for healthcare-associated pneumonia within the Veterans Healthcare Administration

OBJECTIVES

The objective of this study was to measure quantitatively antimicrobial de-escalation utilizing electronic medication administration data based on the spectrum of activity for antimicrobial therapy (i.e. spectrum score) to identify variables associated with de-escalation in a nationwide healthcare system.

METHODS

A retrospective cohort study of patients hospitalized for healthcare-associated pneumonia was conducted in Veterans Affairs Medical Centers (n = 119). Patients hospitalized for healthcare-associated pneumonia on acute-care wards between 5 and 14 days who received antimicrobials for ≥ 3 days during calendar years 2008-11 were evaluated. The spectrum score method was applied at the patient level to measure de-escalation on day 4 of hospitalization. De-escalation was expressed in aggregate and facility-level proportions. Logistic regression was used to assess variables associated with de-escalation. ORs with 95% CIs were reported.

RESULTS

Among 9319 patients, the de-escalation proportion was 28.3% (95% CI 27.4-29.2), which varied 6-fold across facilities [median (IQR) facility-level de-escalation proportion 29.1% (95% CI 21.7-35.6)]. Variables associated with de-escalation included initial broad-spectrum therapy (OR 1.5, 95% CI 1.4-1.5 for each 10% increase in spectrum), collection of respiratory tract cultures (OR 1.1, 95% CI 1.0-1.2) and care in higher complexity facilities (OR 1.3, 95% CI 1.1-1.6). Respiratory tract cultures were collected from 35.3% (95% CI 32.7-37.7) of patients.

CONCLUSIONS

De-escalation of antimicrobial therapy was limited and varied substantially across facilities. De-escalation was associated with respiratory tract culture collection and treatment in a high complexity-level facility.

Antibiotic de-escalation in the ICU: how is it best done?

PURPOSE OF REVIEW

An antimicrobial policy consisting of the initial use of wide-spectrum antimicrobials followed by a reassessment of treatment when culture results are available is termed de-escalation therapy. Our aim is to examine the safety and feasibility of antibiotic de-escalation in critically ill patients providing practical tips about how to accomplish this strategy in the critical care setting.

RECENT FINDINGS

Numerous studies have assessed the rates of de-escalation therapy (range from 10 to 60%) in patients with severe sepsis or ventilator-associated pneumonia as well as the factors associated with de-escalation. De-escalation generally refers to a reduction in the spectrum of administered antibiotics through the discontinuation of antibiotics or switching to an agent with a narrower spectrum. Diverse studies have identified the adequacy of initial therapy as a factor independently associated with de-escalation. Negative impact on different outcome measures has not been reported in the observational studies. Two randomized clinical trials have evaluated this strategy in patients with ventilator-associated pneumonia or severe sepsis. These trials alert us about the possibility that this strategy may be linked to a higher rate of reinfections but without an impact on mortality.

SUMMARY

Antibiotic de-escalation is a well tolerated management strategy in critically ill patients but unfortunately is not widely adopted.

Assessment of empirical antibiotic therapy optimisation in six hospitals: an observational cohort study

BACKGROUND

Modification of empirical antimicrobials when warranted by culture results or clinical signs is recommended to control antimicrobial overuse and resistance. We aimed to assess the frequency with which patients were started on empirical antimicrobials, characteristics of the empirical regimen and the clinical characteristics of patients at the time of starting antimicrobials, patterns of changes to empirical therapy at different timepoints, and modifiable factors associated with changes to the initial empirical regimen in the first 5 days of therapy.

METHODS

We did a chart review of adult inpatients receiving one or more antimicrobials in six US hospitals on 4 days during 2009 and 2010. Our primary outcome was the modification of antimicrobial regimen on or before the 5th day of empirical therapy, analysed as a three-category variable. Bivariate analyses were used to establish demographic and clinical variables associated with the outcome. Variables with p values below 0·1 were included in a multivariable generalised linear latent and mixed model with multinomial logit link to adjust for clustering within hospitals and accommodate a non-binary outcome variable.

FINDINGS

Across the six study sites, 4119 (60%) of 6812 inpatients received antimicrobials. Of 1200 randomly selected patients with active antimicrobials, 730 (61%) met inclusion criteria. At the start of therapy, 220 (30%) patients were afebrile and had normal white blood cell counts. Appropriate cultures were collected from 432 (59%) patients, and 250 (58%) were negative. By the 5th day of therapy, 12·5% of empirical antimicrobials were escalated, 21·5% were narrowed or discontinued, and 66·4% were unchanged. Narrowing or discontinuation was more likely when cultures were collected at the start of therapy (adjusted OR 1·68, 95% CI 1·05-2·70) and no infection was noted on an initial radiological study (1·76, 1·11-2·79). Escalation was associated with multiple infection sites (2·54, 1·34-4·83) and a positive culture (1·99, 1·20-3·29).

INTERPRETATION

Broad-spectrum empirical therapy is common, even when clinical signs of infection are absent. Fewer than one in three inpatients have their regimens narrowed within 5 days of starting empirical antimicrobials. Improved diagnostic methods and continued education are needed to guide discontinuation of antimicrobials.

FUNDING

US Centers for Disease Control and Prevention, Division of Healthcare Quality Promotion; Robert Wood Johnson Foundation; US Department of Veterans Administration; US Department of Homeland Security.

Development of an antibiotic spectrum score based on veterans affairs culture and susceptibility data for the purpose of measuring antibiotic de-escalation: a modified Delphi approach

OBJECTIVE

Development of a numerical score to measure the microbial spectrum of antibiotic regimens (spectrum score) and method to identify antibiotic de-escalation events based on application of the score.

DESIGN

Web-based modified Delphi method.

PARTICIPANTS

Physician and pharmacist antimicrobial stewards practicing in the United States recruited through infectious diseases-focused listservs.

METHODS

Three Delphi rounds investigated: organisms and antibiotics to include in the spectrum score, operationalization of rules for the score, and de-escalation measurement. A 4-point ordinal scale was used to score antibiotic susceptibility for organism-antibiotic domain pairs. Antibiotic regimen scores, which represented combined activity of antibiotics in a regimen across all organism domains, were used to compare antibiotic spectrum administered early (day 2) and later (day 4) in therapy. Changes in spectrum score were calculated and compared with Delphi participants' judgments on de-escalation with 20 antibiotic regimen vignettes and with non-Delphi steward judgments on de-escalation of 300 pneumonia regimen vignettes. Method sensitivity and specificity to predict expert de-escalation status were calculated.

RESULTS

Twenty-four participants completed all Delphi rounds. Expert support for concepts utilized in metric development was identified. For vignettes presented in the Delphi, the sign of change in score correctly classified de-escalation in all vignettes except those involving substitution of oral antibiotics. The sensitivity and specificity of the method to identify de-escalation events as judged by non-Delphi stewards were 86.3% and 96.0%, respectively.

CONCLUSIONS

Identification of de-escalation events based on an algorithm that measures microbial spectrum of antibiotic regimens generally agreed with steward judgments of de-escalation status.

Safety and feasibility of antibiotic de-escalation in bacteremic pneumonia

Background

Antibiotic de-escalation is a potential strategy advocated to conserve the effectiveness of broad-spectrum antibiotics. The aim of this study was to examine the safety and feasibility of antibiotic de-escalation in patients admitted with bacteremic pneumonia.

Methods

A retrospective chart review was done for patients with bacteremic pneumonia admitted to Northwest Texas Hospital in Amarillo, TX, USA, during 2008. Antibiotic de-escalation was defined as changing the empiric antibiotic regimen to a culture-directed single agent with a narrower spectrum than the original regimen.

Results

Sixty-eight patients were admitted with bacteremic pneumonia. Eight patients were not eligible for de-escalation. Among the 60 patients who were eligible for de-escalation, the treating physicians failed to de-escalate antibiotics in 27 cases (45.0%). Discharge to a long-term care facility predicted failure to de-escalate antibiotics, while an infectious diseases consultation was significantly associated with antibiotic de-escalation. The average daily cost of antibacterial therapy in the de-escalation group was $25.7 compared with $61.6 in the group where de-escalation was not implemented. The difference in mean length of hospital stay and mortality between the two groups was not statistically significant.

Conclusion

Antibiotic de-escalation is a safe management strategy but unfortunately is not widely adopted. Although bacterial resistance poses a significant threat and is rising, antimicrobial de-escalation has emerged as a potential intervention that can conserve the effectiveness of broad-spectrum antibiotics without compromising the patient’s outcome. This practice is becoming important in the face of slow development of new anti-infective agents.

The "de-escalation concept" and antibiotic de-escalation: a missed opportunity?

"De-escalation therapy" is a term that suggests the need to reduce the spectrum or the number of antibiotics formerly prescribed for critical patients, upon clinical improvement and/or microorganism recovery. The major goal of this concept is the use of broad-spectrum antibiotic agents as initial drugs of choice for severe patients, instead of "reserving" the most potent agents after an inadequate clinical response, or after the microorganism is recovered. Despite possible commercial concerns and an unproven but possible relationship with enhancing global antibiotic use, the concept was correct and in accordance with scientific evidence. However, the "de-escalation" component of the concept is very seldom reported, and no large clinical trial on this issue is available until today. To definitely put in practice this concept, comparative large trials must be designed and sponsored to insert this strategy at the same level of evidence of wide initial empiric antibiotic treatments.

The management of pneumonia in internal medicine

Pneumonia generates a high workload for internal medicine departments. Management of this disease is challenging, because patients are usually elderly and have multiple comorbid conditions. Furthermore, the interpretation and adherence to guidelines are far from clear in this setting. We report the opinion of 43 internists especially interested in infectious diseases that were questioned at the 2011 XXXII National Conference of Spanish Society of Internal Medicine about the main issues involved in the management of pneumonia in the internal medicine departments, namely, classification, admission criteria, microbiological workup, therapeutic management, discharge policy, and prevention of future episodes. Participants were asked to choose between 2 options for each statement by 4 investigators. Consensus could not be reached in many cases. The most controversial issues concerned recognition and management of healthcare-associated pneumonia (HCAP). Most participants were aware of the differences in terms of underlying diseases, etiological distribution, and outcome of HCAP compared with community-acquired pneumonia, but only a minority agreed to manage HCAP as hospital-acquired pneumonia, as suggested by some guidelines. A clinical patient-to-patient approach proved to be the option preferred by internists in the management of HCAP.

Nosocomial pneumonia: lessons learned

Nosocomial pneumonia remains a significant cause of hospital-acquired infection, imposing substantial economic burden on the health care system worldwide. Various preventive strategies have been increasingly used to prevent the development of pneumonia. It is now recognized that patients with health care-associated pneumonia are a heterogeneous population and that not all are at risk for infection with nosocomial pneumonia pathogens, with some being infected with the same organisms as in community-acquired pneumonia. This review discusses the risk factors for nosocomial pneumonia, controversies in its diagnosis, and approaches to the treatment and prevention of nosocomial and health care-associated pneumonia.

A trial of discontinuation of empiric vancomycin therapy in patients with suspected methicillin-resistant Staphylococcus aureus health care-associated pneumonia

Healthcare-associated pneumonia (HCAP) guidelines recommend de-escalating initial antibiotic therapy based on results from lower-respiratory-tract cultures. In the absence of adequate lower respiratory cultures, physicians are sometimes reluctant to discontinue empirical vancomycin, which is given for suspected methicillin-resistant Staphylococcus aureus (MRSA) HCAP. We evaluated a strategy of discontinuing vancomycin if both nasal and throat cultures were negative for MRSA when lower-respiratory-tract cultures were not available. An antimicrobial stewardship team identified patients receiving empirical vancomycin for suspected or proven HCAP but for whom adequate lower-respiratory-tract cultures were not available. Nasal and throat swab specimens were obtained and plated on MRSA selective media. If both nasal and throat MRSA cultures were negative, the stewardship team recommended discontinuation of empirical vancomycin. Demographic and clinical aspects, a clinical pulmonary infection score (CPIS) on the day of the stewardship recommendation, and mortality of patients for whom vancomycin was discontinued were obtained by retrospective chart review. A convenience sample of 91 patients with nasal and throat cultures negative for MRSA in the absence of adequate respiratory cultures had empirical vancomycin therapy discontinued. A retrospective review revealed that 88 (97%) patients had a CPIS of ≤6 on the day of the stewardship recommendation. In-hospital mortality (7.7%) was similar to that of a previous study of de-escalation of antibiotics in pneumonia patients without adequate cultures. In the absence of adequate lower-respiratory-tract cultures, it is reasonable to discontinue empirical vancomycin HCAP therapy in patients with negative MRSA nasal and throat cultures and a CPIS of <6.

Guideline-based antibiotics and mortality in healthcare-associated pneumonia

BACKGROUND

Guidelines recommend administration of antibiotics with activity against methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa for treatment of healthcare-associated pneumonia (HCAP). It is unclear if this therapy improves outcomes for patients with HCAP.

OBJECTIVE

To determine if administration of guideline-similar therapy (GST) was associated with a reduction in 30-day mortality for HCAP.

DESIGN

Multi-center retrospective study.

PARTICIPANTS

Thirteen hundred and eleven admissions for HCAP in six Veterans Affairs Medical Centers.

INTERVENTIONS

Each admission was classified as receiving GST, anti-MRSA or anti-pseudomonal components of GST, or other non-HCAP therapy initiated within 48 hours of hospitalization. Association between 30-day mortality and GST was estimated with a logistic regression model that included GST, propensity to receive GST, probability of recovering an organism from culture resistant to antibiotics traditionally used to treat community-acquired pneumonia (CAP-resistance), and a GST by CAP-resistance probability interaction.

MAIN MEASURES

Odds ratios and 95% confidence intervals [OR (95% CI)] of 30-day mortality for patients treated with GST and predicted probability of recovering a CAP-resistant organism, and ratio of odds ratios [ROR (95% CI)] for treatment by CAP-resistance probability interaction.

KEY RESULTS

Receipt of GST was associated with increased odds of 30-day mortality [OR = 2.11 (1.11, 4.04), P = 0.02)] as was the predicted probability of recovering a CAP-resistant organism [OR = 1.67 (1.26, 2.20), P < 0.001 for a 25% increase in probability]. An interaction between predicted probability of recovering a CAP-resistant organism and receipt of GST demonstrated lower mortality with GST at high probability of CAP resistance [ROR = 0.71(≤1.00) for a 25% increase in probability, P = 0.05].

CONCLUSIONS

For HCAP patients with high probability of CAP-resistant organisms, GST was associated with lower mortality. Consideration of the magnitude of patient-specific risk for CAP-resistant organisms should be considered when selecting HCAP therapy.

Is healthcare-associated pneumonia a distinct entity needing specific therapy?

PURPOSE OF REVIEW

Healthcare-associated pneumonia (HCAP) was introduced in 2005 by American Thoracic Society/Infectious Diseases Society of America guidelines as a new entity of pneumonia, resembling nosocomial pneumonia rather than community-acquired pneumonia (CAP) in terms of frequency of multidrug-resistant (MDR) pathogens and outcomes, thus requiring broad spectrum initial antimicrobial coverage in order to prevent inadequate treatment and, as a consequence, excess mortality. This concept continues to be a subject of controversy. Main concerns relate to the definition of HCAP, the true frequency of MDR pathogens, and the impact of MDR pathogens on outcomes.

RECENT FINDINGS

Definitions of HCAP and the relative frequencies of HCAP defining subgroups were highly variable. All studies demonstrated an increased severity of pneumonia at presentation and an excess mortality from HCAP as compared to CAP. The incidence of MDR pathogens in different observational studies was slightly increased but generally low in most studies originating from Europe, South Korea, Canada, and Japan. However, the data do not support a causal relationship of MDR incidence and excess mortality. Instead, after adjustment for confounders, mortality might be related to hidden or documented treatment restrictions in elderly and severely disabled patients. Accordingly, HCAP guideline concordant antimicrobial treatment did not improve outcomes.

SUMMARY

The HCAP concept is based on varying definitions poorly predictive of MDR pathogens. The incidence of MDR pathogens is far lower than supposed in the original guideline document, and MDR pathogens do not seem to be the main cause of excess mortality. Broad antimicrobial coverage does not alter outcomes. As the HCAP concept results in a tremendous overtreatment without any evidence for improved outcomes, it should not be implemented in clinical practice prior to clear evidence that it is superior to a careful assessment of individual risk factors for MDR pathogens.

Inhaled antibiotic therapy for ventilator-associated tracheobronchitis and ventilator-associated pneumonia: an update

Ventilator-associated pneumonia (VAP) remains a leading cause of morbidity and mortality in mechanically-ventilated patients in the Intensive Care Unit (ICU). Ventilator-associated tracheobronchitis (VAT) was previously believed to be an intermediate stage between colonization of the lower respiratory tract and VAP. More recent data, however, suggest that VAT may be a separate entity that increases morbidity and mortality, independently of the occurrence of VAP. Some, but not all, patients with VAT progress to develop VAP. Although inhaled antibiotics alone could be effective for the treatment of VAP, the current consensus of opinion favors their role as adjuncts to systemic antimicrobial therapy for VAP. Inhaled antibiotics are increasingly employed for salvage therapy in patients with VAP due to multi-drug resistant Gram-negative bacteria. In contrast to VAP, VAT could be effectively treated with inhaled antibiotic therapy alone or in combination with systemic antimicrobials.

Healthcare-associated pneumonia: approach to management

Healthcare-associated pneumonia patients have worse outcomes and a different microbiologic profile than those with community-acquired pneumonia, including a greater risk for multidrug-resistant (MDR) organism infection. Risks include hospitalization for 2 or more days within 90 days, presentation from a nursing home or long-term care facility, attending a hospital or hemodialysis clinic, receiving intravenous therapy within 30 days, and immunosuppression. Ability to predict infection with MDR organisms varies, and the relative frequency of MDR organisms varies by geographic region. Initial treatment is broad-spectrum empiric antibiotics.