Derivation and Multicenter Validation of the Drug Resistance in Pneumonia Clinical Prediction Score

Bacterial profile, and independent predictors for healthcare-associated pneumonia persistently caused by multidrug-resistant Gram-negative bacteria for patients with the preceding multidrug-resistant Gram-negative pneumonia in Taiwan

OBJECTIVES

To understand the microbial profile and investigate the independent predictors for healthcare-associated pneumonia (HCAP) pertinaciously caused by isolates of multidrug-resistant (MDR) Gram-negative bacteria (GNB).

METHODS

Multicenter ICU patients who received appropriate antibiotic treatments for preceding pneumonia due to MDR GNB isolates and subsequently developed HCAP caused by either MDR GNB (n = 126) or non-MDR GNB (n = 40) isolates in Taiwan between 2018 and 2023 were enrolled. Between the groups of patients with HCAP due to MDR GNB and non-MDR GNB, the proportions of the following variables, including demographic characteristics, important co-morbidities, nursing home residence, physiological severity, intervals between two hospitalizations, steroid use, the tracheostomy tube use alone, ventilator support, and the predominant GNB species involving HCAP, were analyzed using the chi-square test. Logistic regression was employed to explore the independent predictors for HCAP persistently caused by MDR GNB in the aforementioned variables with a P-value of <0.15 in the univariate analysis.

RESULTS

MDR-Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii complex were the three predominant species causing HCAP. Chronic structural lung disorders, diabetes mellitus, intervals of ≤30 days between two hospitalizations, use of the tracheostomy tube alone, and prior pneumonia caused by MDR A. baumannii complex were shown to independently predict the HCAP tenaciously caused by MDR GNB. Conversely, the preceding pneumonia caused by MDR P. aeruginosa was a negative predictor.

CONCLUSION

Identifying predictors for HCAP persistently caused by MDR GNB is crucial for prescribing appropriate antibiotics.

Incidence of drug-resistant pathogens in community-acquired pneumonia at a safety net hospital

The 2019 Infectious Diseases Society of America guideline for the management of community-acquired pneumonia (CAP) emphasizes the need for clinician to understand local epidemiological data to guide selection of appropriate treatment. Currently, the local distribution of causative pathogens and their associated resistance patterns in CAP is unknown. A retrospective observational study was performed of patients admitted to an 870-bed safety net hospital between March 2016 and March 2021 who received a diagnosis of CAP or healthcare-associated pneumonia within the first 48 hours of admission. The primary outcome was the incidence of CAP caused by methicillin-resistant Staphylococcus aureus (MRSA) or Pseudomonas aeruginosa (PsA) as determined by comparing the number of satisfactory sputum cultures or blood cultures with these drug-resistant organisms to the total number of reviewed patients. Secondary outcomes studied included risk factors associated with CAP caused by drug-resistant organisms, utilization of broad-spectrum antibiotics, appropriate antibiotic de-escalation within 72 hours, and treatment duration. In this 220-patient cohort, MRSA or PsA was isolated from three sputum cultures and no blood cultures. The local incidence of drug-resistant pathogens among the analyzed sample of CAP patients was 1.4% (n = 3/220). The overall incidence of CAP caused by MRSA or PsA among admitted patients is low at our safety-net county hospital. Future research is needed to identify local risk factors associated with the development of CAP caused by drug-resistant pathogens.IMPORTANCEThis study investigates the incidence of drug-resistant pathogens including methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa among community-acquired pneumonia (CAP) patients at a safety net hospital. Understanding local bacteria resistance patterns when treating CAP is essential and supported by evidence-based guidelines. Our findings empower other clinicians to investigate resistance patterns at their own institutions and identify methods to improve antibiotic use. This has the potential to reduce the unnecessary use of broad-spectrum antibiotic agents and combat the development of antibiotic resistance.

Assessment and examination of the respiratory system

This article aims to outline the fundamental principles of consultations with and clinical assessments of patients with symptoms that may be indicative of respiratory system pathology. The article explores how to perform a respiratory system-focused patient history and physical examination. An evaluation of clinical 'red flags' to reduce the risk of omitting serious illness is also considered, alongside the exploration of features of respiratory pathology and evidence-based clinical decision-making tools that may be used to support clinical diagnosis.

New Guidelines for Severe Community-acquired Pneumonia

In 2023, the new European guidelines on severe community-acquired pneumonia, providing clinical practice recommendations for the management of this life-threatening infection, characterized by a high burden of mortality, morbidity, and costs for the society. This review article aims to summarize the principal evidence related to eight different questions covered in the guidelines, by also highlighting the future perspectives for research activity.

Risk of Multidrug-Resistant Pathogens in Severe Community-Acquired Pneumonia

Severe community-acquired pneumonia (SCAP) is difficult to treat when caused by difficult-to-treat (DTR) pathogens because of limited treatment options and poorer clinical outcomes. Over time, several predictive scoring systems based on risk factors for infection with multidrug resistant pathogens have been developed. We reviewed the available tools for identifying DTR pathogens as the cause of SCAP, both predictive scoring systems and rapid diagnostic methods, to develop management strategies aimed at early identification of DTR pathogens, reducing broad-spectrum antibiotic use and improving clinical outcomes. The scoring systems reviewed show considerable heterogeneity among them at the level of the region studied, the definition of risk factors, as well as which DTR pathogens are the target pathogens. The models described have shown limited effectiveness in reducing inappropriate antibiotic treatment or improving patient outcomes by themselves. However, predictive models could serve as a first step in identifying DTR pathogen infections as part of a larger detection algorithm. Rapid diagnostic tools, such as multiplex polymerase chain reaction, would be useful for the rapid identification of pneumonia-causing pathogens and their resistance mechanisms. In resource-limited settings, rapid tests should be limited to patients at high risk of developing SCAP due to DTR pathogens. We propose an integrative algorithm based on the different scores, taking into account local epidemiological data, where ideally each center should have an antimicrobial stewardship program.

Methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa community acquired pneumonia: Prevalence and locally derived risk factors in a single hospital system

Objectives

Current American Thoracic Society/Infectious Disease Society of America (ATS/IDSA) community-acquired pneumonia (CAP) guidelines expand the CAP definition to include infections occurring in patients with recent health care exposure. The guidelines now recommend that hospital systems determine their own local prevalence and predictors of Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus (MRSA) among patients satisfying this new broader CAP definition. We sought to carry out these recommendations in our system, focusing on the emergency department, where CAP diagnosis and initial empiric antibiotic selection usually ooccur.

Methods

We performed a retrospective cohort study of patients admitted with CAP through any of 3 EDs in our hospital system in Northern California between November 2019 and October 2021. Inclusion criteria included an ED admission diagnosis of pneumonia or sepsis, fever or hypothermia, leukocytosis or leukopenia, and consistent chest imaging result. SARS-CoV-2-positive cases were excluded. We abstracted variables historically associated with P. aeruginosa and MRSA. Outcome measures were prevalence of P. aeruginosa and MRSA in the overall clinically defined cohort and among microbiologically confirmed cases and predictors of P. aeruginosa or MRSA isolation, as determined by univariate logistic regression, bootstrapped least absolute shrinkage and selection operator, and random forest analyses. Additionally, we describe the iterative process used and challenges encountered in carrying out the new ATS/IDSA guideline recommendations.

Results

There were 1133 unique patients who satisfied our definition of clinically defined CAP, of whom 109 (9.6%) had a bacterial pathogen isolated. There were 24 P. aeruginosa isolates and 11 MRSA isolates in 33 patients. Thus, the prevalence P. aeruginosa and MRSA was 2.9% in the overall CAP cohort, but 30.3% in the microbiologically confirmed cohort. The most important predictors of either P. aeruginosa or MRSA isolation were tracheostomy (odds ratio [OR] 22.08; 95% confidence interval [CI] 10.39-46.96) and gastrostomy tube (OR 14.7; 95% CI 7.14-30.26). Challenges included determining the suspected infection type in patients admitted simply for "sepsis"; interpreting dictated radiology reports; determining functional status, presence of indwelling lines and tubes, and long-term care facility residence from the electronic health record; and correctly attributing culture results to pneumonia.

Conclusion

Prevalence of MRSA and P. aeruginosa was low among patients admitted in our medical system with CAP - now broadly defined - but high among those with a microbiologically confirmed bacterial etiology. Our locally derived predictors of MRSA and P. aeruginosa can be used to aid our emergency physicians in empiric antibiotic selection for CAP. Findings from this project might inform efforts at other institutions.

Ten Issues to Update in Nosocomial or Hospital-Acquired Pneumonia: An Expert Review

Nosocomial pneumonia, or hospital-acquired pneumonia (HAP), and ventilator-associated pneumonia (VAP) are important health problems worldwide, with both being associated with substantial morbidity and mortality. HAP is currently the main cause of death from nosocomial infection in critically ill patients. Although guidelines for the approach to this infection model are widely implemented in international health systems and clinical teams, information continually emerges that generates debate or requires updating in its management. This scientific manuscript, written by a multidisciplinary team of specialists, reviews the most important issues in the approach to this important infectious respiratory syndrome, and it updates various topics, such as a renewed etiological perspective for updating the use of new molecular platforms or imaging techniques, including the microbiological diagnostic stewardship in different clinical settings and using appropriate rapid techniques on invasive respiratory specimens. It also reviews both Intensive Care Unit admission criteria and those of clinical stability to discharge, as well as those of therapeutic failure and rescue treatment options. An update on antibiotic therapy in the context of bacterial multiresistance, in aerosol inhaled treatment options, oxygen therapy, or ventilatory support, is presented. It also analyzes the out-of-hospital management of nosocomial pneumonia requiring complete antibiotic therapy externally on an outpatient basis, as well as the main factors for readmission and an approach to management in the emergency department. Finally, the main strategies for prevention and prophylactic measures, many of them still controversial, on fragile and vulnerable hosts are reviewed.

Management of pneumonia in the critically ill

Pneumonias continue to be major public health issues and are commonly encountered in the intensive care setting. The most common types of pneumonia leading to critical illness include severe community acquired pneumonia, hospital acquired pneumonia, and ventilator associated pneumonia. Early evaluation, diagnosis, and escalation to appropriate levels of care are imperative to improving survival. Treatment remains challenging with the need to balance antibiotic stewardship and minimizing patient harm. As evidenced in the most recent society guidelines, the identification of risk factors for severe disease and the causative pathogens are crucial in guiding the most appropriate therapy.

Interventions to improve outcomes in community-acquired pneumonia

INTRODUCTION

Community-acquired pneumonia (CAP) is a common infection associated with high morbimortality and a highly deleterious impact on patients' quality of life and functionality. We comprehensively review the factors related to the host, the causative microorganism, the therapeutic approach and the organization of health systems (e.g. setting for care and systems for allocation) that might have an impact on CAP-associated outcomes. Our main aims are to discuss the most controversial points and to provide some recommendations that may guide further research and the management of patients with CAP, in order to improve their outcomes, beyond mortality.

AREA COVERED

In this review, we aim to provide a critical account of potential measures to improve outcomes of CAP and the supporting evidence from observational studies and clinical trials.

EXPERT OPINION

CAP is associated with high mortality and a highly deleterious impact on patients' quality of life. To improve CAP-associated outcomes, it is important to understand the factors related to the patient, etiology, therapeutics, and the organization of health systems.

Derivation and validation of a risk assessment model for drug-resistant pathogens in hospitalized patients with community-acquired pneumonia

OBJECTIVE

To derive and validate a model for risk of resistance to first-line community-acquired pneumonia (CAP) therapy.

DESIGN

We developed a logistic regression prediction model from a large multihospital discharge database and validated it versus the Drug Resistance in Pneumonia (DRIP) score in a holdout sample and another hospital system outside that database. Resistance to first-line CAP therapy (quinolone or third generation cephalosporin plus macrolide) was based on blood or respiratory cultures.

SETTING

This study was conducted using data from 177 Premier Healthcare database hospitals and 11 Cleveland Clinic hospitals.

PARTICIPANTS

Adults hospitalized for CAP.

EXPOSURE

Risk factors for resistant infection.

RESULTS

Among 138,762 eligible patients in the Premier database, 12,181 (8.8%) had positive cultures and 5,200 (3.8%) had organisms resistant to CAP therapy. Infection with a resistant organism in the previous year was the strongest predictor of resistance; markers of acute illness (eg, receipt of mechanical ventilation or vasopressors) and chronic illness (eg, pressure ulcer, paralysis) were also associated with resistant infections. Our model outperformed the DRIP score with a C-statistic of 0.71 versus 0.63 for the DRIP score (P < .001) in the Premier holdout sample, and 0.65 versus 0.58 (P < .001) in Cleveland Clinic hospitals. Clinicians at Premier facilities used broad-spectrum antibiotics for 20%-30% of patients. In discriminating between patients with and without resistant infections, physician judgment slightly outperformed the DRIP instrument but not our model.

CONCLUSIONS

Our model predicting infection with a resistant pathogen outperformed both the DRIP score and physician practice in an external validation set. Its integration into practice could reduce unnecessary use of broad-spectrum antibiotics.

ERS/ESICM/ESCMID/ALAT guidelines for the management of severe community-acquired pneumonia

PURPOSE

Severe community-acquired pneumonia (sCAP) is associated with high morbidity and mortality, and whilst European and non-European guidelines are available for community-acquired pneumonia, there are no specific guidelines for sCAP.

METHODS

The European Respiratory Society (ERS), European Society of Intensive Care Medicine (ESICM), European Society of Clinical Microbiology and Infectious Diseases (ESCMID), and Latin American Thoracic Association (ALAT) launched a task force to develop the first international guidelines for sCAP. The panel comprised a total of 18 European and four non-European experts, as well as two methodologists. Eight clinical questions for sCAP diagnosis and treatment were chosen to be addressed. Systematic literature searches were performed in several databases. Meta-analyses were performed for evidence synthesis, whenever possible. The quality of evidence was assessed with GRADE (Grading of Recommendations, Assessment, Development and Evaluation). Evidence to Decision frameworks were used to decide on the direction and strength of recommendations.

RESULTS

Recommendations issued were related to diagnosis, antibiotics, organ support, biomarkers and co-adjuvant therapy. After considering the confidence in effect estimates, the importance of outcomes studied, desirable and undesirable consequences of treatment, cost, feasibility, acceptability of the intervention and implications to health equity, recommendations were made for or against specific treatment interventions.

CONCLUSIONS

In these international guidelines, ERS, ESICM, ESCMID, and ALAT provide evidence-based clinical practice recommendations for diagnosis, empirical treatment, and antibiotic therapy for sCAP, following the GRADE approach. Furthermore, current knowledge gaps have been highlighted and recommendations for future research have been made.

Identify Drug-Resistant Pathogens in Patients with Community-Acquired Pneumonia

A substantial increase in broad-spectrum antibiotics as empirical therapy in patients with community-acquired pneumonia (CAP) has occurred over the last 15 years. One of the driving factors leading to that has been some evidence showing an increased incidence of drug-resistant pathogens (DRP) in patients from a community with pneumonia, including methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa. Research has been published attempting to identify DRP in CAP through the implementation of probabilistic approaches in clinical practice. However, recent epidemiological data showed that the incidence of DRP in CAP varies significantly according to local ecology, healthcare systems and countries where the studies were performed. Several studies also questioned whether broad-spectrum antibiotic coverage might improve outcomes in CAP, as it is widely documented that broad-spectrum antibiotics overuse is associated with increased costs, length of hospital stay, drug adverse events and resistance. The aim of this review is to analyze the different approaches used to identify DRP in CAP patients as well as the outcomes and adverse events in patients undergoing broad-spectrum antibiotics.

ERS/ESICM/ESCMID/ALAT guidelines for the management of severe community-acquired pneumonia

BACKGROUND

Severe community-acquired pneumonia (sCAP) is associated with high morbidity and mortality, and while European and non-European guidelines are available for community-acquired pneumonia, there are no specific guidelines for sCAP.

MATERIALS AND METHODOLOGY

The European Respiratory Society (ERS), European Society of Intensive Care Medicine (ESICM), European Society of Clinical Microbiology and Infectious Diseases (ESCMID) and Latin American Thoracic Association (ALAT) launched a task force to develop the first international guidelines for sCAP. The panel comprised a total of 18 European and four non-European experts, as well as two methodologists. Eight clinical questions for sCAP diagnosis and treatment were chosen to be addressed. Systematic literature searches were performed in several databases. Meta-analyses were performed for evidence synthesis, whenever possible. The quality of evidence was assessed with GRADE (Grading of Recommendations, Assessment, Development and Evaluation). Evidence to Decision frameworks were used to decide on the direction and strength of recommendations.

RESULTS

Recommendations issued were related to diagnosis, antibiotics, organ support, biomarkers and co-adjuvant therapy. After considering the confidence in effect estimates, the importance of outcomes studied, desirable and undesirable consequences of treatment, cost, feasibility, acceptability of the intervention and implications to health equity, recommendations were made for or against specific treatment interventions.

CONCLUSIONS

In these international guidelines, ERS, ESICM, ESCMID and ALAT provide evidence-based clinical practice recommendations for diagnosis, empirical treatment and antibiotic therapy for sCAP, following the GRADE approach. Furthermore, current knowledge gaps have been highlighted and recommendations for future research have been made.

Machine Learning To Stratify Methicillin-Resistant Staphylococcus aureus Risk among Hospitalized Patients with Community-Acquired Pneumonia

Methicillin-resistant Staphylococcus aureus (MRSA) is an uncommon but serious cause of community-acquired pneumonia (CAP). A lack of validated MRSA CAP risk factors can result in overuse of empirical broad-spectrum antibiotics. We sought to develop robust models predicting the risk of MRSA CAP using machine learning using a population-based sample of hospitalized patients with CAP admitted to either a tertiary academic center or a community teaching hospital. Data were evaluated using a machine learning approach. Cases were CAP patients with MRSA isolated from blood or respiratory cultures within 72 h of admission; controls did not have MRSA CAP. The Classification Tree Analysis algorithm was used for model development. Model predictions were evaluated in sensitivity analyses. A total of 21 of 1,823 patients (1.2%) developed MRSA within 72 h of admission. MRSA risk was higher among patients admitted to the intensive care unit (ICU) in the first 24 h who required mechanical ventilation than among ICU patients who did not require ventilatory support (odds ratio [OR], 8.3; 95% confidence interval [CI], 2.4 to 32). MRSA risk was lower among patients admitted to ward units than among those admitted to the ICU (OR, 0.21; 95% CI, 0.07 to 0.56) and lower among ICU patients without a history of antibiotic use in the last 90 days than among ICU patients with antibiotic use in the last 90 days (OR, 0.03; 95% CI, 0.002 to 0.59). The final machine learning model was highly accurate (receiver operating characteristic [ROC] area = 0.775) in training and jackknife validity analyses. We identified a relatively simple machine learning model that predicted MRSA risk in hospitalized patients with CAP within 72 h postadmission.

How and when to manage respiratory infections out of hospital

Lower respiratory infections include acute bronchitis, influenza, community-acquired pneumonia, acute exacerbation of COPD and acute exacerbation of bronchiectasis. They are a major cause of death worldwide and often affect the most vulnerable: children, elderly and the impoverished. In this paper, we review the clinical presentation, diagnosis, severity assessment and treatment of adult outpatients with lower respiratory infections. The paper is divided into sections on specific lower respiratory infections, but we also dedicate a section to COVID-19 given the importance of the ongoing pandemic. Lower respiratory infections are heterogeneous entities, carry different risks for adverse events, and require different management strategies. For instance, while patients with acute bronchitis are rarely admitted to hospital and generally do not require antimicrobials, approximately 40% of patients seen for community-acquired pneumonia require admission. Clinicians caring for patients with lower respiratory infections face several challenges, including an increasing population of patients with immunosuppression, potential need for diagnostic tests that may not be readily available, antibiotic resistance and social aspects that place these patients at higher risk. Management principles for patients with lower respiratory infections include knowledge of local surveillance data, strategic use of diagnostic tests according to surveillance data, and judicious use of antimicrobials.

Severe community-acquired pneumonia

Severe community-acquired pneumonia is the most life-threatening form of community-acquired pneumonia, characterised by intensive care unit admission and high morbidity and mortality. In this review article, we cover in depth six aspects of severe community-acquired pneumonia that are still controversial: use of PCR molecular techniques for microbial diagnosis; the role of biomarkers for initial management; duration of treatment, macrolides or quinolones in the initial empirical antibiotic therapy; the use of prediction scores for drug-resistant pathogens to modify initial empiric therapy; the use of noninvasive mechanical ventilation and high-flow nasal oxygen; and the use of corticosteroids as adjunctive therapy in severe community-acquired pneumonia.

Extended-Spectrum Antibiotics for Community-Acquired Pneumonia with a Low Risk of Drug-Resistant Pathogens

OBJECTIVES

The potential hazards of extended-spectrum antibiotic therapy for patients with community-acquired pneumonia (CAP) with low risk of drug-resistant pathogens (DRPs) remains unclear, although risk assessment for DRPs is essential to determine the initial antibiotics to be administered. The study objective is to assess the effect of unnecessary extended-spectrum therapy on mortality of such patients.

METHODS

A post-hoc analysis was conducted after a prospective multicenter observational study for CAP. Multivariable logistic regression analysis was performed to assess the effect of extended-spectrum therapy on 30-day mortality. Three sensitivity analyses, including propensity score analysis to confirm the robustness of findings, were also performed.

RESULTS

Among 750 patients with CAP, 416 with CAP with a low risk of DRPs were analyzed; of these, 257 underwent standard therapy and 159 underwent extended-spectrum therapy. The 30-day mortality was 3.9% and 13.8% in the standard and extended-spectrum therapy groups, respectively. Primary analysis revealed that extended-spectrum therapy was associated with increased 30-day mortality compared with standard therapy (adjusted odds ratio, 2.82; 95% confidence interval, 1.20-6.66). The results of the sensitivity analyses were consistent with those of the primary analysis.

CONCLUSIONS

Physicians should assess the risk of DRPs when determining the empirical antibiotic therapy and should refrain from administering unnecessary extended-spectrum antibiotics for patients with CAP with a low risk of DRPs.

It's about the patients: Practical antibiotic stewardship in outpatient settings in the United States

Antibiotic-resistant pathogens cause over 35,000 preventable deaths in the United States every year, and multiple strategies could decrease morbidity and mortality. As antibiotic stewardship requirements are being deployed for the outpatient setting, community providers are facing systematic challenges in implementing stewardship programs. Given that the vast majority of antibiotics are prescribed in the outpatient setting, there are endless opportunities to make a smart and informed choice when prescribing and to move the needle on antibiotic stewardship. Antibiotic stewardship in the community, or "smart prescribing" as we suggest, should factor in antibiotic efficacy, safety, local resistance rates, and overall cost, in addition to patient-specific factors and disease presentation, to arrive at an appropriate therapy. Here, we discuss some of the challenges, such as patient/parent pressure to prescribe, lack of data or resources for implementation, and a disconnect between guidelines and real-world practice, among others. We have assembled an easy-to-use best practice guide for providers in the outpatient setting who lack the time or resources to develop a plan or consult lengthy guidelines. We provide specific suggestions for antibiotic prescribing that align real-world clinical practice with best practices for antibiotic stewardship for two of the most common bacterial infections seen in the outpatient setting: community-acquired pneumonia and skin and soft-tissue infection. In addition, we discuss many ways that community providers, payors, and regulatory bodies can make antibiotic stewardship easier to implement and more streamlined in the outpatient setting.

Derivation and Validation of a Clinical Prediction Score to Identify the Isolation of Pseudomonas in Pneumonia

Given the focus of existing clinical prediction scores on identifying drug-resistant pathogens as a whole, the application to individual pathogens and other institutions may yield weaker performance. This study aimed to develop a locally derived clinical prediction model for Pseudomonas-mediated pneumonia. This retrospective study included patients ≥18 years of age who were admitted to an academic medical center between 1 July 2010 and 31 July 2020 with a CDC National Healthcare Safety Network confirmed pneumonia diagnosis and were receiving antimicrobials during the index encounter, with a positive respiratory culture. Cystic fibrosis patients were excluded. Logistic regression analysis identified risk factors associated with the isolation of Pseudomonas aeruginosa from respiratory cultures within the derivation cohort (n = 186), which were weighted to generate a prediction score that was applied to the derivation and internal validation (n = 95) cohorts. A total of 281 patients met the inclusion criteria. Five predictor variables were identified, namely, tracheostomy status (4 points), chronic obstructive pulmonary disease (5 points), enteral nutrition (9 points), chronic steroid use (11 points), and Pseudomonas aeruginosa isolation from any culture in the prior 6 months (14 points). At a score of >11, the prediction score demonstrated a sensitivity of 52.4% (95% confidence interval [CI], 36.4 to 68.0%) and a specificity of 84.9% (95% CI, 72.4 to 93.35%) in the validation cohort. Score accuracy was 70.5% (95% CI, 60.3 to 79.4%), and the area under the receiver operating characteristic curve (AUROC) was 0.77 (95% CI, 0.68 to 0.87) in the validation cohort. A prediction score for identifying Pseudomonas aeruginosa in pneumonia was derived, which may have the potential to decrease the use of broad-spectrum antibiotics. Validation with larger and external cohorts is necessary.

IMPORTANCE In this study, we aimed to develop a locally derived clinical prediction model for Pseudomonas-mediated pneumonia. Utilizing a locally validated prediction score may help direct therapeutic management and be generalizable to other clinical settings and similar populations for the selection of appropriate antimicrobial coverage when data are lacking. Our study highlights a unique patient population, including immunocompromised, structural lung disease, and transplant patients. Five predictor variables were identified, namely, tracheostomy status, chronic obstructive pulmonary disease, enteral nutrition, chronic steroid use, and Pseudomonas aeruginosa isolation from any culture in the prior 6 months. A prediction score for identifying Pseudomonas aeruginosa in pneumonia was derived, which may have the potential to decrease the use of broad-spectrum antibiotics, although validation with larger and external cohorts is necessary.

Empiric Treatment in HAP/VAP: “Don’t You Want to Take a Leap of Faith?”

Ventilator-associated pneumonia is a frequent cause of ICU-acquired infections. These infections are associated with high morbidity and mortality. The increase in antibiotic resistance, particularly among Gram-negative bacilli, makes the choice of empiric antibiotic therapy complex for physicians. Multidrug-resistant organisms (MDROs) related infections are associated with a high risk of initial therapeutic inadequacy. It is, therefore, necessary to quickly identify the bacterial species involved and their susceptibility to antibiotics. New diagnostic tools have recently been commercialized to assist in the management of these infections. Moreover, the recent enrichment of the therapeutic arsenal effective on Gram-negative bacilli raises the question of their place in the therapeutic management of these infections. Most national and international guidelines recommend limiting their use to microbiologically documented infections. However, many clinical situations and, in particular, the knowledge of digestive or respiratory carriage by MDROs should lead to the discussion of the use of these new molecules, especially the new combinations with beta-lactamase inhibitors in empirical therapy. In this review, we present the current epidemiological data, particularly in terms of MDRO, as well as the clinical and microbiological elements that may be taken into account in the discussion of empirical antibiotic therapy for patients managed for ventilator-associated pneumonia.

Risk factors for community-onset pneumonia caused by drug-resistant pathogens: A prospective cohort study

INTRODUCTION

There is no consensual definition of risk factors for drug resistant pathogens (DRP) in community-onset pneumonia (COP). Healthcare-associated pneumonia criteria have been abandoned because they were found to have weak discriminative power. Our aim was to identify risk factors for DRP in COP.

METHODS

Prospective cohort study, conducted over a two years' period, in a community-based hospital, including all adult patients with COP criteria. Univariate and multivariate logistic regression modeling were performed to understand the association of risk factors (demographic, clinical and epidemiological) with COP by a DRP (PES: Pseudomonas aeruginosa, extended-spectrum ß-lactamase producing Enterobacteriaceae, Methicillin-resistant Staphylococcus aureus; and other non-fermenting gram-negative bacteria, namely Acinetobacter baumannii).

RESULTS

A total of 660 cases of COP were included, with a mean (±SD) age of 74±15 years and 58.9% of males. Microbiological documentation was possible in 32.6% of the cases. There were 197 cases selected for further analysis, of which 37 were cases of PES. The multivariate logistic regression model retained antibiotic use in the previous 90 days (adjusted OR=4.411, 95%CI [1.745-11.148]) and being bed-ridden (adjusted OR=5.492, 95%CI [2.121-14.222]), adjusted for Charlson's Index, CURB 65 and provenience from a long-term care facility. The area under the ROC curve for this model was 0.832, 95%CI [0.756-0.908], higher than the application of the HCAP criteria (AUROC = 0.676, 95%CI [0.582-0.770]).

CONCLUSION

In this study, antibiotic use in the previous 90 days and being bed-ridden were independently associated with COP caused by DRP, after adjustment for Charlson's Index, CURB 65 and provenience from a long-term care facility.

Deploying an Electronic Clinical Decision Support Tool for Diagnosis and Treatment of Pneumonia Into Rural and Critical Access Hospitals: Utilization, Effect on Processes of Care, and Clinician Satisfaction

PURPOSE

Electronic clinical decision support (CDS) for treatment of community-acquired pneumonia (ePNa) is associated with improved guideline adherence and decreased mortality. How rural providers respond to CDS developed for urban hospitals could shed light on extending CDS to resource-limited settings.

METHODS

ePNa was deployed into 10 rural and critical access hospital emergency departments (EDs) in Utah and Idaho in 2018. We reviewed pneumonia cases identified through ICD-10 codes after local deployment to measure ePNa utilization and guideline adherence. ED providers were surveyed to assess quantitative and qualitative aspects of satisfaction.

FINDINGS

ePNa was used in 109/301 patients with pneumonia (36%, range 0%-67% across hospitals) and was associated with appropriate antibiotic selection (93% vs 65%, P < .001). Fifty percent of survey recipients responded, 87% were physicians, 87% were men, and the median ED experience was 10 years. Mean satisfaction with ePNa was 3.3 (range 1.7-4.8) on a 5-point Likert scale. Providers with a favorable opinion of ePNa were more likely to favor implementation of additional CDS (P = .005). Satisfaction was not associated with provider type, age, years of experience or experience with ePNa. Ninety percent of respondents provided qualitative feedback. The most common theme in high and low utilization hospitals was concern about usability. Compared to high utilization hospitals, low utilization hospitals more frequently identified concerns about adaptation for local needs.

CONCLUSIONS

ePNa deployment to rural and critical access EDs was moderately successful and associated with improved antibiotic use. Concerns about usability and adapting ePNa for local use predominated the qualitative feedback.

Diagnosis of Multidrug-Resistant Pathogens of Pneumonia

Hospital-acquired pneumonia and ventilator-associated pneumonia that are caused by multidrug resistant (MDR) pathogens represent a common and severe problem with increased mortality. Accurate diagnosis is essential to initiate appropriate antimicrobial therapy promptly while simultaneously avoiding antibiotic overuse and subsequent antibiotic resistance. Here, we discuss the main conventional phenotypic diagnostic tests and the advanced molecular tests that are currently available to diagnose the primary MDR pathogens and the resistance genes causing pneumonia.

Advances in novel antibiotics to treat multidrug-resistant gram-negative bacterial infections

Antimicrobial resistance is a growing threat to public health and an increasingly common problem for acute care physicians to confront. Several novel antibiotics have been approved in the past decade to combat these infections; however, physicians may be unfamiliar with how to appropriately utilize them. The purpose of this review is to evaluate novel antibiotics active against resistant gram-negative bacteria and highlight clinical information regarding their use in the acute care setting. This review focuses on novel antibiotics useful in the treatment of infections caused by resistant gram-negative organisms that may be seen in the acute care setting. These novel antibiotics include ceftolozane/tazobactam, ceftazidime/avibactam, meropenem/vaborbactam, imipenem/cilistatin/relebactam, cefiderocol, plazomicin, eravacycline, and omadacycline. Acute care physicians should be familiar with these novel antibiotics so they can utilize them appropriately.

Validation of a Prediction Score for Drug-Resistant Microorganisms in Community-acquired Pneumonia

Rationale: Recommended initial empiric antimicrobial treatment covers the most common bacterial pathogens; however, community-acquired pneumonia (CAP) may be caused by microorganisms not targeted by this treatment. Developed in 2015, the PES (Pseudomonas aeruginosa, extended-spectrum β-lactamase-producing Enterobacteriaceae, and methicillin-resistant Staphylococcus aureus) score was developed in 2015 to predict the microbiological etiology of CAP caused by PES microorganisms.Objective: To validate the usefulness of the PES score for predicting PES microorganisms in two cohorts of patients with CAP from Valencia and Mataró.Methods: We analyzed two prospective observational cohorts of patients with CAP from Valencia and Mataró. Patients in the Mataró cohort were all admitted to an intensive care unit (ICU).Results: Of the 1,024 patients in the Valencia cohort, 505 (51%) had a microbiological etiology and 31 (6%) had a PES microorganism isolated. The area under the receiver operating characteristic curve was 0.81 (95% confidence interval [95% CI], 0.74-0.88). For a PES score ≥5, sensitivity, specificity, the negative and positive predictive values as well as the negative and positive likelihood ratios were 72%, 74%, 98%, 14%, 0.38, and 2.75, respectively. Of the 299 patients in the Mataró cohort, 213 (71%) had a microbiological etiology and 11 (5%) had a PES microorganism isolated. The area under the receiver operating characteristic curve was 0.73 (95% CI 0.61-0.86). For a PES score ≥ 5, sensitivity, specificity, the negative and positive predictive values, and the negative and positive likelihood ratios were 36%, 83%, 96%, 11%, 0.77, and 2.09, respectively. The best cutoff for patients admitted to the ICU was 4 points, which improved sensitivity to 86%. The hypothetical application of the PES score showed high rates of overtreatment in both cohorts (26% and 35%, respectively) and similar rates of undertreatment.Conclusions: The PES score showed good accuracy in predicting the risk for microorganisms that required different empirical therapy; however, its use as a single strategy for detecting noncore pathogens could lead to high rates of overtreatment. Given its high negative predictive value, the PES score may be used as a first step of a wider strategy that includes subsequent advanced diagnostic tests.

[Management of Adult Community-Acquired Pneumonia and Prevention - Update 2021 - Guideline of the German Respiratory Society (DGP), the Paul-Ehrlich-Society for Chemotherapy (PEG), the German Society for Infectious Diseases (DGI), the German Society of Medical Intensive Care and Emergency Medicine (DGIIN), the German Viological Society (DGV), the Competence Network CAPNETZ, the German College of General Practitioneers and Family Physicians (DEGAM), the German Society for Geriatric Medicine (DGG), the German Palliative Society (DGP), the Austrian Society of Pneumology Society (ÖGP), the Austrian Society for Infectious and Tropical Diseases (ÖGIT), the Swiss Respiratory Society (SGP) and the Swiss Society for Infectious Diseases Society (SSI)]

The present guideline provides a new and updated concept of the management of adult patients with community-acquired pneumonia. It replaces the previous guideline dating from 2016.The guideline was worked out and agreed on following the standards of methodology of a S3-guideline. This includes a systematic literature search and grading, a structured discussion of recommendations supported by the literature as well as the declaration and assessment of potential conflicts of interests.The guideline has a focus on specific clinical circumstances, an update on severity assessment, and includes recommendations for an individualized selection of antimicrobial treatment.The recommendations aim at the same time at a structured assessment of risk for adverse outcome as well as an early determination of treatment goals in order to reduce mortality in patients with curative treatment goal and to provide palliation for patients with treatment restrictions.

Blood Cultures Versus Respiratory Cultures: 2 Different Views of Pneumonia

BACKGROUND

Choice of empiric therapy for pneumonia depends on risk for antimicrobial resistance. Models to predict resistance are derived from blood and respiratory culture results. We compared these results to understand if organisms and resistance patterns differed by site. We also compared characteristics and outcomes of patients with positive cultures by site.

METHODS

We studied adult patients discharged from 177 US hospitals from July 2010 through June 2015, with principal diagnoses of pneumonia, or principal diagnoses of respiratory failure, acute respiratory distress syndrome, respiratory arrest, or sepsis with a secondary diagnosis of pneumonia, and who had blood or respiratory cultures performed. Demographics, treatment, microbiologic results, and outcomes were examined.

RESULTS

Among 138 561 hospitalizations of patients with pneumonia who had blood or respiratory cultures obtained at admission, 12 888 (9.3%) yielded positive cultures: 6438 respiratory cultures, 5992 blood cultures, and 458 both respiratory and blood cultures. Forty-two percent had isolates resistant to first-line therapy for community-acquired pneumonia. Isolates from respiratory samples were more often resistant than were isolates from blood (54.2% vs 26.6%; P < .001). Patients with both culture sites positive had higher case-fatality, longer lengths of stay, and higher costs than patients who had only blood or respiratory cultures positive. Among respiratory cultures, the most common pathogens were Staphylococcus aureus (34%) and Pseudomonas aeruginosa (17%), whereas blood cultures most commonly grew Streptococcus pneumoniae (33%), followed by S. aureus (22%).

CONCLUSIONS

Patients with positive respiratory tract cultures are clinically different from those with positive blood cultures, and resistance patterns differ by source. Models of antibiotic resistance should account for culture source.

Pneumonia

Pneumonia is a common acute respiratory infection that affects the alveoli and distal airways; it is a major health problem and associated with high morbidity and short-term and long-term mortality in all age groups worldwide. Pneumonia is broadly divided into community-acquired pneumonia or hospital-acquired pneumonia. A large variety of microorganisms can cause pneumonia, including bacteria, respiratory viruses and fungi, and there are great geographical variations in their prevalence. Pneumonia occurs more commonly in susceptible individuals, including children of <5 years of age and older adults with prior chronic conditions. Development of the disease largely depends on the host immune response, with pathogen characteristics having a less prominent role. Individuals with pneumonia often present with respiratory and systemic symptoms, and diagnosis is based on both clinical presentation and radiological findings. It is crucial to identify the causative pathogens, as delayed and inadequate antimicrobial therapy can lead to poor outcomes. New antibiotic and non-antibiotic therapies, in addition to rapid and accurate diagnostic tests that can detect pathogens and antibiotic resistance will improve the management of pneumonia.

A "resistance calculator": Simple stewardship intervention for refining empiric practices of antimicrobials in acute-care hospitals

Objective:

In the era of widespread resistance, there are 2 time points at which most empiric prescription errors occur among hospitalized adults: (1) upon admission (UA) when treating patients at risk of multidrug-resistant organisms (MDROs) and (2) during hospitalization, when treating patients at risk of extensively drug-resistant organisms (XDROs). These errors adversely influence patient outcomes and the hospital’s ecology.

Design and setting:

Retrospective cohort study, Shamir Medical Center, Israel, 2016.

Patients:

Adult patients (aged >18 years) hospitalized with sepsis.

Methods:

Logistic regressions were used to develop predictive models for (1) MDRO UA and (2) nosocomial XDRO. Their performances on the derivation data sets, and on 7 other validation data sets, were assessed using the area under the receiver operating characteristic curve (ROC AUC).

Results:

In total, 4,114 patients were included: 2,472 patients with sepsis UA and 1,642 with nosocomial sepsis. The MDRO UA score included 10 parameters, and with a cutoff of ≥22 points, it had an ROC AUC of 0.85. The nosocomial XDRO score included 7 parameters, and with a cutoff of ≥36 points, it had an ROC AUC of 0.87. The range of ROC AUCs for the validation data sets was 0.7–0.88 for the MDRO UA score and was 0.66–0.75 for nosocomial XDRO score. We created a free web calculator (https://assafharofe.azurewebsites.net).

Conclusions:

A simple electronic calculator could aid with empiric prescription during an encounter with a septic patient. Future implementation studies are needed to evaluate its utility in improving patient outcomes and in reducing overall resistances.

Strategies for prediction of drug-resistant pathogens and empiric antibiotic selection in community-acquired pneumonia

PURPOSE OF REVIEW

Although most patients with community-acquired pneumonia (CAP) are appropriately treated with narrow-spectrum antibiotics, predicting which patients require coverage of drug-resistant pathogens (DRP) remains a challenge. The 2019 American Thoracic Society/Infectious Diseases Society of America CAP guidelines endorse using locally validated prediction models for DRP. Here we review risk factors for DRP and provide a summary of available risk prediction models.

RECENT FINDINGS

Both inadequate initial empiric spectrum as well as unnecessary broad-spectrum antibiotic use are associated with poor outcomes in CAP. Multiple prediction models for DRP-based patient-level risk factors have been published, with some variation in included predictor variables and test performance characteristics. Seven models have been robustly externally validated, and implementation data have been published for two of these models. All models demonstrated better performance than the healthcare-associated pneumonia criteria, with most favoring sensitivity over specificity. We also report validation of the novel, risk factor-based treatment algorithm proposed in the American Thoracic Society/Infectious Diseases Society of America guidelines which strongly favors specificity over sensitivity, especially in nonsevere pneumonia.

SUMMARY

Using patient-level risk factors to guide the decision whether to prescribe broad-spectrum antibiotics is a rational approach to treatment. Several viable candidate prediction models are available. Hospitals should evaluate the local performance of existing scores before implementing in routine clinical practice.

Simulated Adoption of 2019 Community-Acquired Pneumonia Guidelines Across 114 Veterans Affairs Medical Centers: Estimated Impact on Culturing and Antibiotic Selection in Hospitalized Patients

BACKGROUND

The 2019 American Thoracic Society/Infectious Diseases Society of America guidelines for community-acquired pneumonia (CAP) revised recommendations for culturing and empiric broad-spectrum antibiotics. We simulated guideline adoption in Veterans Affairs (VA) inpatients.

METHODS

For all VA acute hospitalizations for CAP from 2006-2016 nationwide, we compared observed with guideline-expected proportions of hospitalizations with initial blood and respiratory cultures obtained, empiric antibiotic therapy with activity against methicillin-resistant Staphylococcus aureus (anti-MRSA) or Pseudomonas aeruginosa (antipseudomonal), empiric "overcoverage" (receipt of anti-MRSA/antipseudomonal therapy without eventual detection of MRSA/P. aeruginosa on culture), and empiric "undercoverage" (lack of anti-MRSA/antipseudomonal therapy with eventual detection on culture).

RESULTS

Of 115 036 CAP hospitalizations over 11 years, 17 877 (16%) were admitted to an intensive care unit (ICU). Guideline adoption would slightly increase respiratory culture (30% to 36%) and decrease blood culture proportions (93% to 36%) in hospital wards and increase both respiratory (40% to 100%) and blood (95% to 100%) cultures in ICUs. Adoption would decrease empiric selection of anti-MRSA (ward: 27% to 1%; ICU: 61% to 8%) and antipseudomonal (ward: 25% to 1%; ICU: 54% to 9%) therapies. This would correspond to greatly decreased MRSA overcoverage (ward: 27% to 1%; ICU: 56% to 8%), slightly increased MRSA undercoverage (ward: 0.6% to 1.3%; ICU: 0.5% to 3.3%), with similar findings for P. aeruginosa. For all comparisons, P < .001.

CONCLUSIONS

Adoption of the 2019 CAP guidelines in this population would substantially change culturing and empiric antibiotic selection practices, with a decrease in overcoverage and slight increase in undercoverage for MRSA and P. aeruginosa.

Validation of a Community-Acquired Pneumonia Score To Improve Empiric Antibiotic Selection at an Academic Medical Center

The 2019 American Thoracic Society and the Infectious Diseases Society of America community-acquired pneumonia (CAP) guidelines recommend that drug-resistant pathogens (DRP) be empirically covered if locally validated risk factors are present. This retrospective case-control validation study evaluated the performance of the drug resistance in pneumonia (DRIP) clinical prediction score. Two hundred seventeen adult patients with ICD-10 (https://www.who.int/classifications/classification-of-diseases) pneumonia diagnosis, positive confirmed microbiologic data, and clinical signs and symptoms were included. A DRIP score of ≥4 was used to assess model performance. Logistic regression was used to select for significant predictors and create a modified DRIP score, which was evaluated to define clinical application. The DRIP score predicted pneumonia due to a DRP with a sensitivity of 67% and specificity of 73%. The area under the receiver operating characteristic (AUROC) curve was 0.76 (95% confidence interval [CI], 0.69 to 0.82). From regression analysis, prior infection with a DRP and antibiotics in the last 60 days, yielding scores of 2 points and 1 point, respectively, remained local risk factors in predicting drug-resistant pneumonia. Sensitivity (47%) and specificity (94%) were maximized at a threshold of ≥2 in the modified DRIP model. Therefore, prior infection with a DRP remained the only clinically relevant predictor for drug-resistant pneumonia. The original DRIP score demonstrated a decreased performance in our patient population and behaved similarly to other clinical prediction models. Empiric CAP therapy without anti-methicillin-resistant Staphylococcus aureus and antipseudomonal coverage should be considered for noncritically ill patients without a drug resistant pathogen infection in the past year. Our data support the necessity of local validation to authenticate clinical risk predictors for drug-resistant pneumonia.

A Pathway for Community-Acquired Pneumonia With Rapid Conversion to Oral Therapy Improves Health Care Value

Background

Evidence supports streamlined approaches for inpatients with community-acquired pneumonia (CAP) including early transition to oral antibiotics and shorter therapy. Uptake of these approaches is variable, and the best approaches to local implementation of infection-specific guidelines are unknown. Our objective was to evaluate the impact of a clinical decision support (CDS) tool linked with a clinical pathway on CAP care.

Methods

This is a retrospective, observational pre–post intervention study of inpatients with pneumonia admitted to a single academic medical center. Interventions were introduced in 3 sequential 6-month phases; Phase 1: education alone; Phase 2: education and a CDS-driven CAP pathway coupled with active antimicrobial stewardship and provider feedback; and Phase 3: education and a CDS-driven CAP pathway without active stewardship. The 12 months preceding the intervention were used as a baseline. Primary outcomes were length of intravenous antibiotic therapy and total length of antibiotic therapy. Clinical, process, and cost outcomes were also measured.

Results

The study included 1021 visits. Phase 2 was associated with significantly lower length of intravenous and total antibiotic therapy, higher procalcitonin lab utilization, and a 20% cost reduction compared with baseline. Phase 3 was associated with significantly lower length of intravenous antibiotic therapy and higher procalcitonin lab utilization compared with baseline.

Conclusions

A CDS-driven CAP pathway supplemented by active antimicrobial stewardship review led to the most robust improvements in antibiotic use and decreased costs with similar clinical outcomes.

A Therapeutic Strategy for All Pneumonia Patients: A 3-Year Prospective Multicenter Cohort Study Using Risk Factors for Multidrug-resistant Pathogens to Select Initial Empiric Therapy

BACKGROUND

Empiric therapy of pneumonia is currently based on the site of acquisition (community or hospital), but could be chosen, based on risk factors for multidrug-resistant (MDR) pathogens, independent of site of acquisition.

METHODS

We prospectively applied a therapeutic algorithm based on MDR risks, in a multicenter cohort study of 1089 patients with 656 community-acquired pneumonia (CAP), 238 healthcare-associated pneumonia (HCAP), 140 hospital-acquired pneumonia (HAP), or 55 ventilator-associated pneumonia (VAP).

RESULTS

Approximately 83% of patients were treated according to the algorithm, with 4.3% receiving inappropriate therapy. The frequency of MDR pathogens varied, respectively, with VAP (50.9%), HAP (27.9%), HCAP (10.9%), and CAP (5.2%). Those with ≥2 MDR risks had MDR pathogens more often than those with 0-1 MDR risk (25.8% vs 5.3%, P < .001). The 30-day mortality rates were as follows: VAP (18.2%), HAP (13.6%), HCAP (6.7%), and CAP (4.7%), and were lower in patients with 0-1 MDR risks than in those with ≥2 MDR risks (4.5% vs 12.5%, P < .001). In multivariate logistic regression analysis, 5 risk factors (advanced age, hematocrit <30%, malnutrition, dehydration, and chronic liver disease), as well as hypotension and inappropriate therapy were significantly correlated with 30-day mortality, whereas the classification of pneumonia type (VAP, HAP, HCAP, CAP) was not.

CONCLUSIONS

Individual MDR risk factors can be used in a unified algorithm to guide and simplify empiric therapy for all pneumonia patients, and were more important than the classification of site of pneumonia acquisition in determining 30-day mortality.

CLINICAL TRIALS REGISTRATION

JMA-IIA00146.

Calculated parenteral initial treatment of bacterial infections: Economic aspects of antibiotic treatment

This is the seventeenth chapter of the guideline "Calculated initial parenteral treatment of bacterial infections in adults - update 2018" in the 2nd updated version. The German guideline by the Paul-Ehrlich-Gesellschaft für Chemotherapie e.V. (PEG) has been translated to address an international audience. This chapter analyses economic aspects of antiinfective therapy. Any treatment decision is also a cost decision. In this chapter the authors particularly analyse whether or not there is evidence that certain clinically effective strategies as Antimicrobial Stewardship programs (AMS), guideline adherent initial therapy, early diagnostics, De-escalation, sequence therapy or therapeutic drug monitoring also have benficial economic effects. These can be direct savings or shortening of length of stay to free resources.

Diagnosis and Treatment of Adults with Community-acquired Pneumonia. An Official Clinical Practice Guideline of the American Thoracic Society and Infectious Diseases Society of America

Background: This document provides evidence-based clinical practice guidelines on the management of adult patients with community-acquired pneumonia.

Methods: A multidisciplinary panel conducted pragmatic systematic reviews of the relevant research and applied Grading of Recommendations, Assessment, Development, and Evaluation methodology for clinical recommendations.

Results: The panel addressed 16 specific areas for recommendations spanning questions of diagnostic testing, determination of site of care, selection of initial empiric antibiotic therapy, and subsequent management decisions. Although some recommendations remain unchanged from the 2007 guideline, the availability of results from new therapeutic trials and epidemiological investigations led to revised recommendations for empiric treatment strategies and additional management decisions.

Conclusions: The panel formulated and provided the rationale for recommendations on selected diagnostic and treatment strategies for adult patients with community-acquired pneumonia.

Implementation of Real-Time Electronic Clinical Decision Support for Emergency Department Patients with Pneumonia Across a Healthcare System

A real-time electronic CDS for pneumonia (ePNa) identifies possible pneumonia patients, measures severity and antimicrobial resistance risk, and then recommends disposition, antibiotics, and microbiology studies. Use is voluntary, and clinicians may modify treatment recommendations. ePNa was associated with lower mortality in emergency department (ED) patients versus usual care (Annals EM 66:511). We adapted ePNa for the Cerner EHR, and implemented it across Intermountain Healthcare EDs (Utah, USA) throughout 2018. We introduced ePNa through didactic, interactive presentations to ED clinicians; follow-up visits identified barriers and facilitators to use. Email reminded clinicians and answered questions. Hospital admitting clinicians encouraged ePNa use to smooth care transitions. Audit-and-feedback measured utilization, showing variations from best practice when ePNa and associated electronic order sets were not used. Use was initially low, but gradually increased especially at larger hospitals. A user-friendly interface, frequent reminders, audit-and- feedback, a user survey, a nurse educator, and local physician champions are additive towards implementation success.

Outcomes associated with the use of a revised risk assessment strategy to predict antibiotic resistance in community-onset pneumonia: a stewardship perspective

Objectives

There is growing evidence that patients with community-onset pneumonia and recent healthcare exposure are not at equally high risk of infection with MDR organisms. An individualized approach is necessary with regard to risk assessment and choice of antibiotics.

Methods

We reviewed the records of 102 patients admitted for community-onset pneumonia, before and after the implementation of a revised risk assessment programme for MDR organisms using the drug resistance in pneumonia (DRIP) score. The primary aim of the study was to identify the effects of this intervention on antibiotic days of therapy (DOT), and secondary outcomes included all-cause readmissions and time to clinical improvement. Statistical analysis was performed using generalized linear regression and Cox hazards models.

Results

Implementation of the programme resulted in a decrease in anti-MRSA (-1.44 DOT, P = 0.007) and anti-pseudomonal (-2.03 DOT, P < 0.001) antibiotic utilization, but was not associated with a significant difference in the odds of readmissions (OR 0.64, 95% CI 0.16-2.57) or in time to clinical improvement (HR 1.19, 95% CI 0.62-2.21).

Conclusions

An individualized MDR organism risk assessment strategy using a clinical prediction score for community-onset pneumonia can decrease the utilization of broad-spectrum antibiotics without an increase in adverse outcomes.

Broad-spectrum antibiotic use and poor outcomes in community-onset pneumonia: a cohort study

QUESTION

Is broad-spectrum antibiotic use associated with poor outcomes in community-onset pneumonia after adjusting for confounders?

METHODS

We performed a retrospective, observational cohort study of 1995 adults with pneumonia admitted from four US hospital emergency departments. We used multivariable regressions to investigate the effect of broad-spectrum antibiotics on 30-day mortality, length of stay, cost and Clostridioides difficile infection (CDI). To address indication bias, we developed a propensity score using multilevel (individual provider) generalised linear mixed models to perform inverse-probability of treatment weighting (IPTW) to estimate the average treatment effect in the treated. We also manually reviewed a sample of mortality cases for antibiotic-associated adverse events.

RESULTS

39.7% of patients received broad-spectrum antibiotics, but drug-resistant pathogens were recovered in only 3%. Broad-spectrum antibiotics were associated with increased mortality in both the unweighted multivariable model (OR 3.8, 95% CI 2.5-5.9; p<0.001) and IPTW analysis (OR 4.6, 95% CI 2.9-7.5; p<0.001). Broad-spectrum antibiotic use by either analysis was also associated with longer hospital stay, greater cost and increased CDI. Healthcare-associated pneumonia was not associated with mortality independent of broad-spectrum antibiotic use. In manual review we identified antibiotic-associated events in 17.5% of mortality cases.

CONCLUSION

Broad-spectrum antibiotics appear to be associated with increased mortality and other poor outcomes in community-onset pneumonia.

Antibiotic Use and Outcomes After Implementation of the Drug Resistance in Pneumonia Score in ED Patients With Community-Onset Pneumonia

BACKGROUND

To guide rational antibiotic selection in community-onset pneumonia, we previously derived and validated a novel prediction tool, the Drug-Resistance in Pneumonia (DRIP) score. In 2015, the DRIP score was integrated into an existing electronic pneumonia clinical decision support tool (ePNa).

METHODS

We conducted a quasi-experimental, pre-post implementation study of ePNa with DRIP score (2015) vs ePNa with health-care-associated pneumonia (HCAP) logic (2012) in ED patients admitted with community-onset pneumonia to four US hospitals. Using generalized linear models, we used the difference-in-differences method to estimate the average treatment effect on the treated with respect to ePNa with DRIP score on broad-spectrum antibiotic use, mortality, hospital stay, and cost, adjusting for available patient-level confounders.

RESULTS

We analyzed 2,169 adult admissions: 1,122 in 2012 and 1,047 in 2015. A drug-resistant pathogen was recovered in 3.2% of patients in 2012 and 2.8% in 2015; inadequate initial empirical antibiotics were prescribed in 1.1% and 0.5%, respectively (P = .12). A broad-spectrum antibiotic was administered in 40.1% of admissions in 2012 and 33.0% in 2015 (P < .001). Vancomycin days of therapy per 1,000 patient days in 2012 were 287.3 compared with 238.8 in 2015 (P < .001). In the primary analysis, the average treatment effect among patients using the DRIP score was a reduction in broad-spectrum antibiotic use (OR, 0.62; 95% CI, 0.39-0.98; P = .039). However, the average effects for ePNa with DRIP on mortality, length of stay, and cost were not statistically significant.

CONCLUSIONS

Electronic calculation of the DRIP score was more effective than HCAP criteria for guiding appropriate broad-spectrum antibiotic use in community-onset pneumonia.

Healthcare-associated pneumonia: is there any reason to continue to utilize this label in 2019?

BACKGROUND

There is an ongoing controversy on the role of the healthcare-associated pneumonia (HCAP) label in the treatment of patients with pneumonia.

OBJECTIVE

To provide an update of the literature on patients meeting criteria for HCAP between 2014 and 2018.

SOURCES

The review is based on a systematic literature search using PubMed-Central full-text archive of biomedical and life sciences literature at the U.S. National Institutes of Health's National Library of Medicine (NIH/NLM).

CONTENT

Studies compared clinical characteristics of patients with HCAP and community-acquired pneumonia (CAP). HCAP patients were older and had a higher comorbidity. Mortality rates in HCAP varied from 5% to 33%, but seemed lower than those cited in the initial reports. Criteria behind the HCAP classification differed considerably within populations. Microbial patterns differed in that there was a higher incidence of methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa, and, to a lesser extent, enterobacteriaceae. Definitions and rates of multidrug-resistant (MDR) pneumonia also varied considerably. Broad-spectrum guideline-concordant treatment did not reduce mortality in four observational studies. The HCAP criteria performed poorly as a predictive tool to identify MDR pneumonia or pathogens not covered by treatment for CAP. A new score (Drug Resistance in Pneumonia, DRIP) outperformed HCAP in the prediction of MDR pathogens. Comorbidity and functional status, but not different microbial patterns, seem to account for increased mortality.

IMPLICATIONS

HCAP should no longer be used to identify patients at risk of MDR pathogens. The use of validated predictive scores along with implementation of de-escalation strategies and careful individual assessment of comorbidity and functional status seem superior strategies for clinical management.

PES Pathogens in Severe Community-Acquired Pneumonia

Worldwide, there is growing concern about the burden of pneumonia. Severe community-acquired pneumonia (CAP) is frequently complicated by pulmonary and extra-pulmonary complications, including sepsis, septic shock, acute respiratory distress syndrome, and acute cardiac events, resulting in significantly increased intensive care admission rates and mortality rates. Streptococcus pneumoniae (Pneumococcus) remains the most common causative pathogen in CAP. However, several bacteria and respiratory viruses are responsible, and approximately 6% of cases are due to the so-called PES (Pseudomonas aeruginosa, extended-spectrum β-lactamase Enterobacteriaceae, and methicillin-resistant Staphylococcus aureus) pathogens. Of these, P. aeruginosa and methicillin-resistant Staphylococcus aureus are the most frequently reported and require different antibiotic therapy to that for typical CAP. It is therefore important to recognize the risk factors for these pathogens to improve the outcomes in patients with CAP.

Development of predictive nomograms for clinical use to quantify the risk of isolating resistance prone organisms in patients with infected foot ulcers

Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus (MRSA) have been considered prevalent pathogens in foot infections. However, whether empiric therapy directed against these organisms is necessary, and in whom to consider treatment, is rather unclear. The aim of this study was to develop predictive algorithms for forecasting the probability of isolating these organisms in the infected wounds of patients in a population where the prevalence of resistant pathogens is low. This was a retrospective study of regression model-based risk factor analysis that included 140 patients who presented with infected, culture positive foot ulcers to two urban hospitals. A total of 307 bacteria were identified, most frequently MRSA (11.1%). P. aeruginosa prevalence was 6.5%. In the multivariable analysis, amputation (odds ratio (OR) 5.75, 95% confidence interval (CI) 1.48-27.63), renal disease (OR 5.46, 95% CI 1.43-25.16) and gangrene (OR 2.78, 95% CI 0.82-9.59) were identified as risk factors associated with higher while diabetes (OR 0.07, 95% CI 0.01-0.34) and Infectious Diseases Society of America infection severity >3 (OR 0.18, 95% CI 0.03-0.65) were associated with lower odds of P. aeruginosa isolation (C statistic 0.81). Similar analysis for MRSA showed that amputation was associated with significantly lower (OR 0.29, 95% CI 0.09-0.79) risk, while history of MRSA infection (OR 5.63, 95% CI 1.56-20.63) and osteomyelitis (OR 2.523, 95% CI 1.00-6.79) was associated with higher odds of isolation (C statistic 0.69). We developed two predictive nomograms with reasonable to strong ability to discriminate between patients who were likely of being infected with P. aeruginosa or MRSA and those who were not. These analyses confirm the association of some, but also question the significance of other frequently described risk factors in predicting the isolation of these organisms.

Antimicrobial Stewardship in the Emergency Department

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

Validation of the prediction rules identifying drug-resistant pathogens in community-onset pneumonia

Background

Appropriate initial antibiotic treatment and avoiding administration of unnecessary broad-spectrum antibiotics are important for the treatment of pneumonia. To achieve this, assessment of risk for drug-resistant pathogens (DRPs) at diagnosis is essential.

Purpose

The aim of this study was to validate a predictive rule for DRPs that we previously proposed (the community-acquired pneumonia drug-resistant pathogen [CAP-DRP] rule), comparing several other predictive methods.

Patients and methods

A prospective observational study was conducted in hospitalized patients with community-onset pneumonia at four institutions in Japan. Pathogens identified as not susceptible to ceftriaxone, ampicillin–sulbactam, macrolides, and respiratory fluoroquinolones were defined as CAP-DRPs.

Results

CAP-DRPs were identified in 73 (10.1%) of 721 patients analyzed. The CAP-DRP rule differentiated low vs high risk of CAP-DRP at the threshold of ≥3 points or 2 points plus any of methicillin-resistant Staphylococcus aureus specific factors with a sensitivity of 0.45, specificity of 0.87, positive predictive value of 0.47, negative predictive value of 0.87, and accuracy of 0.79. Its discrimination performance, area under the receiver operating characteristic curve, was 0.73 (95% confidence interval 0.66–0.79). Specificity of the CAP-DRP rule against CAP-DRPs was the highest among the six predictive rules tested.

Conclusion

The performance of the predictive rules and criteria for CAP-DRPs was limited. However, the CAP-DRP rule yielded high specificity and could specify patients who should be treated with non-broad-spectrum antibiotics, eg, a non-pseudomonal β-lactam plus a macrolide, more precisely.