Factors associated with gravity-dependent distribution on chest CT in elderly patients with community-acquired pneumonia: a retrospective observational study

Treatment strategy for older patients with pneumonia independent of the risk of drug resistance in the world's top country for longevity

The number of older people with impaired swallowing function increases with aging population. Aspiration pneumonia is one of the most cases of pneumonia developing among older people. As aspiration pneumonia may develop as a result of age-related deterioration, it is crucial to consider it as an unavoidable event with aging. While pneumonia is diagnosed based on respiratory symptoms and radiological features, the lung involvement of aspiration pneumonia may be undetectable via a frontal chest radiograph in some cases. Bacterial profiles show the predominance of drug-resistant bacteria, such as Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus (MRSA), but isolated bacteria from respiratory samples do not necessarily indicate causative pathogens. Furthermore, there is no evidence regarding treatment superiority using broad-spectrum antibiotics compared with narrow-spectrum antibiotics. Even if isolated pathogens are a causative factor for pneumonia among older patients, the use of broad-spectrum antibiotics covering the bacteria may not improve their outcomes. Therefore, we propose a treatment strategy independent of the risk of drug resistance focusing on the discrimination of patients who are unlikely to respond to broad-spectrum antibiotics. An aspiration risk is associated with increased in-hospital mortality in patients with pneumonia, which could also lead to a greater risk of poor long-term outcomes with increased 1-year mortality. Advance care planning is now recognized as a process for communication and medical decision-making across the life course. This approach would be widely recommended for older people with aspiration risk.

Aetiological agents of adult community-acquired pneumonia in Japan: systematic review and meta-analysis of published data

OBJECTIVE

Epidemiological information is essential in providing appropriate empiric antimicrobial therapy for pneumonia. This study aimed to clarify the epidemiology of community-acquired pneumonia (CAP) by conducting a systematic review of published studies in Japan.

DESIGN

Systematic review.

DATA SOURCE

PubMed and Ichushi web database (January 1970 to October 2022).

ELIGIBILITY CRITERIA

Clinical studies describing pathogenic micro-organisms in CAP written in English or Japanese, excluding studies on pneumonia other than adult CAP, investigations limited to specific pathogens and case reports.

DATA EXTRACTION AND SYNTHESIS

Patient setting (inpatient vs outpatient), number of patients, concordance with the CAP guidelines, diagnostic criteria and methods for diagnosing pneumonia pathogens as well as the numbers of each isolate. A meta-analysis of various situations was performed to measure the frequency of each aetiological agent.

RESULTS

Fifty-six studies were included and 17 095 cases of CAP were identified. Pathogens were undetectable in 44.1% (95% CI 39.7% to 48.5%). Streptococcus pneumoniae was the most common cause of CAP requiring hospitalisation or outpatient care (20.0% (95% CI 17.2% to 22.8%)), followed by Haemophilus influenzae (10.8% (95% CI 7.3% to 14.3%)) and Mycoplasma pneumoniae (7.5% (95% CI 4.6% to 10.4%)). However, when limited to CAP requiring hospitalisation, Staphylococcus aureus was the third most common at 4.9% (95% CI 3.9% to 5.8%). Pseudomonas aeruginosa was more frequent in hospitalised cases, while atypical pathogens were less common. Methicillin-resistant S. aureus accounted for 40.7% (95% CI 29.0% to 52.4%) of S. aureus cases. In studies that used PCR testing for pan-respiratory viral pathogens, human enterovirus/human rhinovirus (9.4% (95% CI 0% to 20.5%)) and several other respiratory pathogenic viruses were detected. The epidemiology varied depending on the methodology and situation.

CONCLUSION

The epidemiology of CAP varies depending on the situation, such as in the hospital versus outpatient setting. Viruses are more frequently detected by exhaustive genetic searches, resulting in a significant variation in epidemiology.

The Clinical Significance of Anaerobic Coverage in the Antibiotic Treatment of Aspiration Pneumonia: A Systematic Review and Meta-Analysis

INTRODUCTION

Aspiration pneumonia is increasingly recognised as a common condition. While antibiotics covering anaerobes are thought to be necessary based on old studies reporting anaerobes as causative organisms, recent studies suggest that it may not necessarily benefit prognosis, or even be harmful. Clinical practice should be based on current data reflecting the shift in causative bacteria. The aim of this review was to investigate whether anaerobic coverage is recommended in the treatment of aspiration pneumonia.

METHODS

A systematic review and meta-analysis of studies comparing antibiotics with and without anaerobic coverage in the treatment of aspiration pneumonia was performed. The main outcome studied was mortality. Additional outcomes were resolution of pneumonia, development of resistant bacteria, length of stay, recurrence, and adverse effects. The Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines were followed.

RESULTS

From an initial 2523 publications, one randomised control trial and two observational studies were selected. The studies did not show a clear benefit of anaerobic coverage. Upon meta-analysis, there was no benefit of anaerobic coverage in improving mortality (Odds ratio 1.23, 95% CI 0.67-2.25). Studies reporting resolution of pneumonia, length of hospital stay, recurrence of pneumonia, and adverse effects showed no benefit of anaerobic coverage. The development of resistant bacteria was not discussed in these studies.

CONCLUSION

In the current review, there are insufficient data to assess the necessity of anaerobic coverage in the antibiotic treatment of aspiration pneumonia. Further studies are needed to determine which cases require anaerobic coverage, if any.

Impact of Pseudomonas aeruginosa coverage on the prognosis of elderly patients with community-acquired pneumonia

BACKGROUND

Although the 2019 American Thoracic Society and Infectious Diseases Society of America guidelines for community-acquired pneumonia (CAP) recommend the use of antibiotics with Pseudomonas aeruginosa coverage for patients with prior sputum isolation of P. aeruginosa, further research is needed to confirm its clinical outcomes. This study aimed to assess the impact of the use of antibiotics with P. aeruginosa coverage on mortality in elderly CAP patients with sputum isolation of P. aeruginosa.

METHODS

We retrospectively included consecutive elderly patients who were hospitalized for CAP and P. aeruginosa-positive sputum culture. The association between the use of antibiotics with P. aeruginosa coverage and 28-day mortality was assessed based on propensity score to reduce selection bias.

RESULTS

A total of 216 patients were included, and 68 (31%) of them were treated with antibiotics with P. aeruginosa coverage. The number of patients treated with antibiotics with P. aeruginosa coverage was significantly higher among nonsurvivors than among survivors. After adjustment using propensity score, the association between the use of antibiotics with P. aeruginosa coverage and the 28-day mortality was found to be statistically nonsignificant (odds ratio 2.182, 95% confidence interval 0.732-6.508, p = 0.162).

CONCLUSIONS

The use of antibiotics with P. aeruginosa coverage in elderly CAP patients with sputum isolation of P. aeruginosa did not improve their prognosis. A randomized control study is required to identify cases that should be treated with antibiotics covering P. aeruginosa.