Guideline-based antibiotics and mortality in healthcare-associated pneumonia

Definition, Epidemiology, and Pathogenesis of Severe Community-Acquired Pneumonia

The clinical presentation of community-acquired pneumonia (CAP) can vary widely among patients. While many individuals with mild symptoms can be managed as outpatients with excellent outcomes, there is a distinct subgroup of patients who present with severe CAP. In these cases, the mortality rate can reach approximately 25% within 30 days and even up to 50% within a year. It is crucial to focus attention on these patients who are at higher risk. Among the various definitions of severe CAP found in the literature, one commonly used criterion is the requirement for admission to intensive care unit. Notable epidemiological characteristics of these patients include the impact of acute cardiovascular diseases on clinical outcomes and the enduring, independent effect of pneumonia on long-term outcomes. Factors such as pathogen virulence, the presence of comorbidities, and the host response are important contributors to the pathogenesis of severe CAP. In these patients, the host response may be dysregulated and compartmentalized. Gaining a better understanding of the epidemiology and pathogenesis of severe CAP will provide a foundation for the development of new therapies for this condition. This manuscript aims to review the definition, epidemiology, and pathogenesis of severe CAP, shedding light on important aspects that can aid in the improvement of patient care and outcomes.

[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.

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.

Management of ventilator-associated pneumonia in intensive care units: a mixed methods study assessing barriers and facilitators to guideline adherence

Background

Guidelines from the Infectious Diseases Society of America/The American Thoracic Society (IDSA/ATS) provide recommendations for diagnosis and treatment of ventilator-associated pneumonia (VAP). However, the mere presence of guidelines is rarely sufficient to promote widespread adoption and uptake. Using the Systems Engineering Initiative for Patient Safety (SEIPS) model framework, we undertook a study to understand barriers and facilitators to the adoption of the IDSA/ATS guidelines.

Methods

We conducted surveys and focus group discussions of different health care providers involved in the management of VAP. The setting was medical-surgical ICUs at a tertiary academic hospital and a large multispecialty rural hospital in Wisconsin, USA.

Results

Overall, we found that 55 % of participants indicated that they were aware of the IDSA/ATS guideline. The top ranked barriers to VAP management included: 1) having multiple physician groups managing VAP, 2) variation in VAP management by differing ICU services, 3) physicians and level of training, and 4) renal failure complicating doses of antibiotics.

Facilitators to VAP management included presence of multidisciplinary rounds that include nurses, pharmacist and respiratory therapists, and awareness of the IDSA/ATS guideline. This awareness was associated with receiving effective training on management of VAP, keeping up to date on nosocomial infection literature, and belief that performing a bronchoscopy to diagnose VAP would help with expeditious diagnosis of VAP.

Conclusions

Findings from our study complement existing studies by identifying perceptions of the many different types of healthcare workers in ICU settings. These findings have implications for antibiotic stewardship teams, clinicians, and organizational leaders.

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.

Predictors of Pseudomonas and methicillin-resistant Staphylococcus aureus in hospitalized patients with healthcare-associated pneumonia

BACKGROUND AND OBJECTIVE

Patients with healthcare-associated pneumonia (HCAP) are at high risk of infection with multidrug-resistant (MDR) pathogens. Factors discriminating infection with MDR Gram-negative (MDR-GN) organism from infection with methicillin-resistant Staphylococcus aureus (MRSA) are not well understood and patients are often treated for both organisms. This study was performed to determine risk factors predicting pneumonia due to Pseudomonas versus MRSA.

METHODS

Veterans age ≥65 hospitalized with HCAP between 2002 and 2012 were identified from the Veterans Affairs administrative databases. Patients were identified with Pseudomonas pneumonia, MRSA pneumonia or neither according to the International Classification of Diseases, 9th Revision, Clinical Modification codes. We assessed unadjusted and adjusted associations of patient characteristics and HCAP due to Pseudomonas or MRSA.

RESULTS

Of the 61,651 patients with HCAP, 1156 (1.9%) were diagnosed with Pseudomonas pneumonia, 641 (1.0%) with MRSA pneumonia and 59,854 (97.1%) with neither. MRSA pneumonia was positively associated with male gender, age >74, diabetes, chronic obstructive pulmonary disease (COPD), recent nursing home or hospital stay, recent exposure to fluoroquinolone or antibiotics treating Gram-positive organisms, and severe pneumonia. MRSA pneumonia was negatively associated with complicated diabetes. Pseudomonas pneumonia was positively associated with recent hospital stay, immunocompromise, COPD, hemiplegia, recent exposure to inhaled corticosteroids, β-lactam/cephalosporin/carbapenem antibiotics, antibiotics against Gram-positive organisms, 'other antibiotics' and severe pneumonia. Pseudomonas pneumonia was negatively associated with age >84, higher socioeconomic status, drug abuse and diabetes.

CONCLUSIONS

Patient characteristics may assist in identifying patients at risk for HCAP due to Pseudomonas or MRSA.

Application of a methicillin-resistant Staphylococcus aureus risk score for community-onset pneumonia patients and outcomes with initial treatment

BACKGROUND

Community-onset (CO) methicillin-resistant Staphylococcus aureus (MRSA) pneumonia is an evolving problem, and there is a great need for a reliable method to assess MRSA risk at hospital admission. A new MRSA prediction score classifies CO-pneumonia patients into low, medium, and high-risk groups based on objective criteria available at baseline. Our objective was to assess the effect of initial MRSA therapy on mortality in these three risk groups.

METHODS

We conducted a retrospective cohort study using data from the Veterans Health Administration (VHA). Patients were included if they were hospitalized with pneumonia and received antibiotics within the first 48 h of admission. They were stratified into MRSA therapy and no MRSA therapy treatment arms based on antibiotics received in the first 48 h. Multivariable logistic regression was used to adjust for potential confounders.

RESULTS

A total of 80,330 patients met inclusion criteria, of which 36% received MRSA therapy and 64% did not receive MRSA therapy. The majority of patients were classified as either low (51%) or medium (47%) risk, with only 2% classified as high-risk. Multivariable logistic regression analysis demonstrated that initial MRSA therapy was associated with a lower 30-day mortality in the high-risk group (adjusted odds ratio 0.57; 95% confidence interval 0.42-0.77). Initial MRSA therapy was not beneficial in the low or medium-risk groups.

CONCLUSIONS

This study demonstrated improved survival with initial MRSA therapy in high-risk CO-pneumonia patients. The MRSA risk score might help spare MRSA therapy for only those patients who are likely to benefit.

Trends in Antibiotic Use and Nosocomial Pathogens in Hospitalized Veterans With Pneumonia at 128 Medical Centers, 2006-2010

BACKGROUND

In 2005, pneumonia practice guidelines recommended broad-spectrum antibiotics for patients with risk factors for nosocomial pathogens. The impact of these recommendations on the ability of providers to match treatment with nosocomial pathogens is unknown.

METHODS

Among hospitalizations with a principal diagnosis of pneumonia at 128 Department of Veterans Affairs medical centers from 2006 through 2010, we measured annual trends in antibiotic selection; initial blood or respiratory cultures positive for methicillin-resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa, and Acinetobacter species; and alignment between antibiotic coverage and culture results for MRSA and P. aeruginosa, calculating sensitivity, specificity, and diagnostic odds ratio using a 2 × 2 contingency table.

RESULTS

In 95 511 hospitalizations for pneumonia, initial use of vancomycin increased from 16% in 2006 to 31% in 2010, and piperacillin-tazobactam increased from 16% to 27%, and there was a decrease in both ceftriaxone (from 39% to 33%) and azithromycin (change from 39% to 36%) (P < .001 for all). The proportion of hospitalizations with cultures positive for MRSA decreased (from 2.5% to 2.0%; P < .001); no change was seen for P. aeruginosa (1.9% to 2.0%; P = .14) or Acinetobacter spp. (0.2% to 0.2%; P = .17). For both MRSA and P. aeruginosa, sensitivity increased (from 46% to 65% and 54% to 63%, respectively; P < .001) and specificity decreased (from 85% to 69% and 76% to 68%; P < .001), with no significant changes in diagnostic odds ratio (decreases from 4.6 to 4.1 [P = .57] and 3.7 to 3.2 [P = .95], respectively).

CONCLUSIONS

Between 2006 and 2010, we found a substantial increase in the use of broad-spectrum antibiotics for pneumonia despite no increase in nosocomial pathogens. The ability of providers to accurately match antibiotic coverage to nosocomial pathogens remains low.

Staphylococcus aureus infections: epidemiology, pathophysiology, clinical manifestations, and management

Staphylococcus aureus is a major human pathogen that causes a wide range of clinical infections. It is a leading cause of bacteremia and infective endocarditis as well as osteoarticular, skin and soft tissue, pleuropulmonary, and device-related infections. This review comprehensively covers the epidemiology, pathophysiology, clinical manifestations, and management of each of these clinical entities. The past 2 decades have witnessed two clear shifts in the epidemiology of S. aureus infections: first, a growing number of health care-associated infections, particularly seen in infective endocarditis and prosthetic device infections, and second, an epidemic of community-associated skin and soft tissue infections driven by strains with certain virulence factors and resistance to β-lactam antibiotics. In reviewing the literature to support management strategies for these clinical manifestations, we also highlight the paucity of high-quality evidence for many key clinical questions.

Time to Guideline-Based Empiric Antibiotic Therapy in the Treatment of Pneumonia in a Community Hospital: A Retrospective Review

PURPOSE

The 2005 American Thoracic Society/Infectious Diseases Society of America (ATS/IDSA) guidelines for hospital-acquired pneumonia (HAP), ventilator-associated pneumonia (VAP), and health care-associated pneumonia (HCAP) stress the importance of initiating prompt appropriate empiric antibiotic therapy. This study's purpose was to determine the percentage of patients with HAP, VAP, and HCAP who received guideline-based empiric antibiotic therapy and to determine the average time to receipt of an appropriate empiric regimen.

METHODS

A retrospective chart review of adults with HAP, VAP, or HCAP was conducted at a community hospital in suburban Birmingham, Alabama. The hospital's electronic medical record system utilized International Classification of Diseases, Ninth Revision (ICD-9) codes to identify patients diagnosed with pneumonia. The percentage of patients who received guideline-based empiric antibiotic therapy was calculated. The mean time from suspected diagnosis of pneumonia to initial administration of the final antibiotic within the empiric regimen was calculated for patients who received guideline-based therapy.

RESULTS

Ninety-three patients met the inclusion criteria. The overall guideline adherence rate for empiric antibiotic therapy was 31.2%. The mean time to guideline-based therapy in hours:minutes was 7:47 for HAP and 28:16 for HCAP. For HAP and HCAP combined, the mean time to appropriate therapy was 21:55.

CONCLUSION

Guideline adherence rates were lower and time to appropriate empiric therapy was greater for patients with HCAP compared to patients with HAP.

Association of guideline-based antimicrobial therapy and outcomes in healthcare-associated pneumonia

OBJECTIVES

Guidelines for treatment of healthcare-associated pneumonia (HCAP) recommend empirical therapy with broad-spectrum antimicrobials. Our objective was to examine the association between guideline-based therapy (GBT) and outcomes for patients with HCAP.

PATIENTS AND METHODS

We conducted a pharmacoepidemiological cohort study at 346 US hospitals. We included adults hospitalized between July 2007 and June 2010 for HCAP, defined as patients admitted from a nursing home, with end-stage renal disease or immunosuppression, or discharged from a hospital in the previous 90 days. Outcome measures included in-hospital mortality, length of stay and costs.

RESULTS

Of 85 097 patients at 346 hospitals, 31 949 (37.5%) received GBT (one agent against MRSA and at least one against Pseudomonas). Compared with patients who received non-GBT, those who received GBT had a heavier burden of chronic disease and more severe pneumonia. GBT was associated with higher mortality (17.1% versus 7.7%, P < 0.001). Adjustment for demographics, comorbidities, propensity for treatment with GBT and initial severity of disease decreased, but did not eliminate, the association (OR 1.39, 95% CI 1.32-1.47). Using an adaptation of an instrumental variable analysis, GBT was not associated with higher mortality (OR 0.93, 95% CI 0.75-1.16). Adjusted length of stay and costs were also higher with GBT.

CONCLUSIONS

Among patients who met HCAP criteria, GBT was not associated with lower adjusted mortality, length of stay or costs in any analyses. Better criteria are needed to identify patients at risk for MDR infections who might benefit from broad-spectrum antimicrobial coverage.

Audit and Feedback-Focused approach to Evidence-based Care in Treating patients with pneumonia in hospital (AFFECT Study)

BACKGROUND

Pneumonia is the eighth leading cause of death in Canada. Use of guideline-concordant therapy tempers the development of resistance, decreases health care costs, and reduces morbidity and mortality.

OBJECTIVES

The purpose of this study was to optimize the treatment of patients with pneumonia under hospitalist care by focusing on best practice and local antibiogram data. The objectives were to collaborate with a hospitalist representative to optimize in-hospital treatment of patients with community-acquired, hospital-acquired, and health care-associated pneumonia; to complete a baseline audit to determine the proportion of antibiotic orders adhering to the strategy; to present the strategy and baseline audit findings to the hospitalists; to perform a post-intervention audit, with comparison to baseline, and to present results to the hospitalists; to expedite de-escalation to a narrower-spectrum antibiotic; to expedite parenteral-to-oral step-down therapy and promote appropriate duration of therapy; and to determine if a pneumonia scoring system was used.

METHODS

An audit and feedback intervention focusing on pre- and post-intervention retrospective chart audits was completed. Review of pneumonia guidelines and the local antibiogram assisted in identifying the study strategy. A presentation to the hospitalists outlined antimicrobial stewardship principles and described the findings of the baseline audit. Pre- and post-intervention audit results were compared.

RESULTS

Local best-practice treatment algorithms were developed for community-acquired pneumonia and for hospital-acquired and health care-associated pneumonia. The pre-intervention audit covered the period December 2011 to January 2012, with subsequent education and audit results presented to the hospitalists in November 2012. The post-intervention audit covered the period December 2012 to January 2013. Adherence to the treatment algorithms increased from 10% (2/21) in the pre-intervention audit to 38% (5/13) in the post-intervention audit. There was a trend to reduced duration of therapy in the post-intervention group.

CONCLUSION

An audit and feedback intervention related to hospitalists' prescribing for pneumonia increased adherence to local best practice.

Reduction in mortality in severely injured patients following the introduction of the "Treatment of patients with severe and multiple injuries" guideline of the German society of trauma surgery--a retrospective analysis of a level 1 trauma center (2010-2012)

OBJECTIVE

The German society of trauma surgery published the "Treatment of Patients with Severe and Multiple injuries" guideline in 2011. This achieved the highest level of recommendation for guidelines published in Germany. This study investigated if there was an improvement in the survival rates of severed injured patients following the introduction of the guideline in clinical treatment.

METHODS

All patients with an injury severity score ≥16 on primary admission to hospital between January 2010 and December 2012 (a total of 373 patients) were included in this study. The data for these patients were collected from the German Trauma Registry and from patients' hospital records. Patients who were treated in 2010 were compared with patients who were treated in 2011 and 2012, following the introduction of the "treatment of patients with severe and multiple injuries" guideline in the authors' clinic at the beginning of 2011.

RESULTS

Significant differences were found in ISS, RTS, New ISS, and TRISS between 2010 and 2011/2012. No differences were found in the severity of injury when classified by different body regions. Major differences were found in the total volume replacement, the length of emergency surgery, the length of surgery performed within the first 24h and the rate of whole-body computed tomography. The mortality rate dropped from 32.48% in 2010 to 18.75% in 2011/2012 (p=0.003).

CONCLUSIONS

The introduction and use of a guideline-based medical care regime for severely injured patients might reduce the rate of mortality.

Healthcare-associated Pneumonia and Aspiration Pneumonia

Healthcare-associated pneumonia (HCAP) is a new concept of pneumonia proposed by the American Thoracic Society/Infectious Diseases Society of America in 2005. This category is located between community-acquired pneumonia and hospital-acquired pneumonia with respect to the characteristics of the causative pathogens and mortality, and primarily targets elderly patients in healthcare facilities. Aspiration among such patients is recognized to be a primary mechanism for the development of pneumonia, particularly since the HCAP guidelines were published. However, it is difficult to manage patients with aspiration pneumonia because the definition of the condition is unclear, and the treatment is associated with ethical aspects. This review focused on the definition, prevalence and role of aspiration pneumonia as a prognostic factor in published studies of HCAP and attempted to identify problems associated with the concept of aspiration pneumonia.

Outcomes of health care-associated pneumonia empirically treated with guideline-concordant regimens versus community-acquired pneumonia guideline-concordant regimens for patients admitted to acute care wards from home

BACKGROUND

The introduction of the health care-associated pneumonia (HCAP) categorization expanded recommendations for broad-spectrum empiric antibiotics to pneumonia patients presenting from the community with recent health care-system exposure. However, the efficacy of such regimens in improving clinical outcomes in these patients has not been well established.

OBJECTIVE

To compare the clinical outcomes of HCAP patients treated initially with HCAP guideline-concordant antibiotic regimens to those treated initially with community-acquired pneumonia (CAP) guideline-concordant antibiotic regimens.

METHODS

This retrospective study included HCAP patients presenting from home and admitted to general medical wards. HCAP regimen patients were treated empirically with at least 1 antipseudomonal agent. All other patients were assigned to the CAP regimen group. The primary end point was clinical cure at 30 days postdischarge. Subgroup analysis was performed in patients hospitalized 1-30 days and 31-90 days before the HCAP admission.

RESULTS

Of 228 HCAP admissions, 122 patients received CAP regimens and 106 received HCAP regimens. The 2 groups were similar at baseline, including Pneumonia Severity Index scores. Attributable clinical cure occurred in 75.4% of CAP regimen patients and 69.8% of HCAP regimen patients (p = 0.34). Overall clinical cure occurred in 59.8% of CAP regimen patients and 54.7% of HCAP regimen patients (p = 0.44). The CAP regimen group used fewer days of intravenous antibiotics (4.39 vs 7.75, p < 0.0001) and had shorter lengths of stay (6.36 vs 8.58 days, p < 0.0001). For patients hospitalized 31-90 days earlier, clinical cure was higher in the CAP regimen group (attributable, 82.9% vs 60.0%, p = 0.0090; overall, 67.1% vs 47.5%, p = 0.044).

CONCLUSIONS

Compared to CAP guideline-concordant regimens, treatment of HCAP with HCAP guideline-concordant regimens did not increase clinical cure rates and was associated with lower clinical cure rates in patients hospitalized 31-90 days prior to the HCAP admission. This study suggests that broad-spectrum empiric antibiotics may not be necessary in all HCAP patient groups.

Is the present definition of health care-associated pneumonia the best way to define risk of infection with antibiotic-resistant pathogens?

Health care-associated pneumonia (HCAP) is associated with an increased risk of infection with multidrug-resistant pathogens compared with community-acquired pneumonia. Recent studies suggest that the designation of HCAP is a poor predictor of resistant pathogens and that antibiotic coverage for multidrug-resistant pathogens is not necessary in all patients with HCAP. This article reviews existing literature on HCAP, discusses the utility of the current definition of HCAP in identifying patients at risk for potentially drug-resistant pathogens, and compares how well the current HCAP designation predicts the risk of drug-resistant pathogens with other proposed algorithms for doing so.