Relationship Between Clinical Features and Computed Tomographic Findings in Hospitalized Adult Patients With Community-Acquired Pneumonia

CT features of community-acquired pneumonia at the emergency department

BACKGROUND

Chest computed tomography (CT) was reported to improve the diagnosis of community-acquired pneumonia (CAP) as compared to chest X-ray (CXR). The aim of this study is to describe the CT-patterns of CAP in a large population visiting the emergency department and to see if some of them are more frequently missed on CXR.

MATERIALS AND METHODS

This is an ancillary analysis of the prospective multicenter ESCAPED study including 319 patients. We selected the 163 definite or probable CAP based on adjudication committee classification; 147 available chest CT scans were reinterpreted by 3 chest radiologists to identify CAP patterns. These CT-patterns were correlated to epidemiological, biological and microbiological data, and compared between false negative and true positive CXR CAP.

RESULTS

Six patterns were identified: lobar pneumonia (51/147, 35%), including 35 with plurifocal involvement; lobular pneumonia (43/147, 29%); unilobar infra-segmental consolidation (24/147, 16%); bronchiolitis (16/147, 11%), including 4 unilobar bronchiolitis; atelectasis and bronchial abnormalities (8/147, 5.5%); interstitial pneumonia (5/147, 3.5%). Bacteria were isolated in 41% of patients with lobar pneumonia-pattern (mostly Streptococcus pneumoniae and Mycoplasma pneumonia) versus 19% in other patients (p = 0.01). Respiratory viruses were equally distributed within all patterns. CXR was falsely negative in 46/147 (31%) patients. Lobar pneumonia was significantly less missed on CXR than other patterns (p = 0.003), especially lobular pneumonia and unilobar infra-segmental consolidation, missed in 35% and 58% of cases, respectively.

CONCLUSION

Lobar and lobular pneumonias are the most frequent CT-patterns. Lobar pneumonia is appropriately detected on CXR and mainly due to Streptococcus pneumoniae or Mycoplasma pneumoniae. Chest CT is very useful to identify CAP in other CT-patterns. Prior the COVID pandemic, CAP was rarely responsible for interstitial opacities on CT.

Real-world Biapenem vs. Meropenem in the treatment of severe community-acquired pneumonia in children: A propensity score matching analysis

OBJECTIVE

To compare the real-world efficacy and safety of Biapenem and Meropenem for treating severe community-acquired pneumonia (SCAP) in children.

METHODS

We retrospectively evaluated 915 children with SCAP who were treated with Biapenem or Meropenem from August 2018 to June 2022. A 1:1 propensity score matching (PSM) analysis was used to reduce the actual baseline difference between groups.

RESULTS

416 patients participated in the analysis after PSM (Biapenem: Meropenem = 1:1). For the Biapenem group and Meropenem group, the effective rates were 90.4% and 90.9%, respectively (p = 1.0) and the incidence of adverse reactions were 7.7% and 7.2%, respectively (p = 1.0). There were no statistical differences between Biapenem and Meropenem.

CONCLUSION

In general, the efficacy and safety of Biapenem are comparable to Meropenem in the treatment of children with SCAP.

Prognostic factors in patients hospitalized with community-acquired aspiration pneumonia

INTRODUCTION

Patients with aspiration pneumonia (AP) exhibit higher mortality than those with non-AP. However, data regarding predictors of short-term prognosis in patients with community-acquired AP are limited.

METHODS

Patients hospitalized with community-acquired pneumonia (CAP) were retrospectively classified into aspiration pneumonia (AP) and non-AP groups. The AP patients were further divided into nonsurvivors and survivors by 30-day mortality, and various clinical variables were compared between the groups.

RESULTS

Of 1249 CAP patients, 254 (20.3%) were classified into the AP group, of whom 76 patients (29.9%) died within 30 days. CURB-65, pneumonia severity index (PSI), and Infectious Diseases Society of America/American Thoracic Society criteria for severe CAP (SCAP) showed only modest prognostic performance for the prediction of 30-day mortality (c-statistics, 0.635, 0.647, and 0.681, respectively). Along with the PSI and SCAP, Eastern Cooperative Oncology Group performance status (ECOG-PS) and blood biomarkers, including, N-terminal of prohormone brain natriuretic peptide (NT-proBNP) and albumin, were independent predictors of 30-day mortality. In models based on clinical prediction rules, including CURB-65, PSI, and SCAP, the addition of ECOG-PS further improved their c-statistics compared to the clinical prediction rules alone. In the four combinations based on SCAP, ECOG-PS, and two blood biomarkers (NT-proBNP and albumin), the c-statistics further increased to reach approximately 0.8.

CONCLUSIONS

CURB-65, PSI, and SCAP exhibited only modest discriminatory power in predicting the 30-day mortality of patients with community-acquired AP. The addition of performance status and blood biomarkers, including NT-proBNP and albumin, further increased prognostic performance, showing good predictive accuracy in the SCAP-based model.

Clinical relevance of emphysema in patients hospitalized with community-acquired pneumonia: Clinical features and prognosis

INTRODUCTION

Few studies have investigated the influence of emphysema on clinical features of patients presenting with community-acquired pneumonia (CAP).

OBJECTIVES

The aim of this study was to examine the clinical and microbiological features of patients with both CAP and emphysema.

METHODS

This retrospective study included patients with CAP who underwent computed tomography (CT) scan at the time of presentation. Patients were allocated into emphysema and control groups, and clinical variables were compared between the two groups. The emphysema group was further divided into three subgroups (mild, moderate, and severe) according to the extent of emphysema on CT scan. The clinical variables of each subgroup were compared with the control group.

RESULTS

Of 1676 patients, 431 patients (25.7%) were classified into the emphysema group. CAP patients with emphysema were more likely to have a high CURB-65 score and pneumonia severity index and a lower incidence of complicated parapneumonic effusion or empyema. The emphysema group exhibited longer hospital stay. In addition, 30-day mortality in the severe emphysema group was significantly higher compared with the control group. As etiological agents, Streptococcus pneumoniae, Pseudomonas aeruginosa, Enterobacteriaceae, and multidrug-resistant pathogens were significantly more common in the emphysema group compared with the control group.

CONCLUSIONS

The presence of emphysema in CAP patients was associated with a more severe form of CAP, a longer hospital stay, and a lower incidence of complicated parapneumonic effusion or empyema. Moreover, CAP patients with severe emphysema exhibited higher 30-day mortality than those without emphysema.

Clinical and computed tomographic features of Legionella pneumonia with negative urine antigen test results

BACKGROUND

Legionella spp. can cause severe pneumonia and most Legionella pneumonia (LP) cases are diagnosed using the urine antigen test (UAT). However, diagnosis of LP with negative UAT results (LPNUAT) is challenging. We investigated the clinical and radiological features of LPNUAT.

METHODS

We retrospectively collected LP cases with positive UAT (LPPUAT) and cases of suspected LP with negative UAT that were examined by Legionella culture between July 2014 and March 2020. We investigated the clinical and CT findings for LP that showed negative UAT results and was diagnosed by culture and compared these findings with those for other pneumonias suspicious for LP with negative results in UAT and Legionella culture (OPSLP).

RESULTS

Eight LPNUAT, 20 LPPUAT, and 19 OPSLP cases were included in this study. There were no significant differences in the clinical and CT findings between LPPUAT and LPNUAT when examined by UAT. In LPNUAT, dyspnea, renal dysfunction, liver dysfunction, and bilateral lesions were more commonly observed and inflammatory changes and the number of affected lobes were significantly higher when examined by culture than when examined by UAT. Comparison to OPSLP, LPNUAT did not show such differences, but rather showed disturbances in consciousness, hyponatremia and rhabdomyolysis. Furthermore, lobar consolidation was observed more frequently and bronchial wall thickening and centrilobular nodules were observed less frequently in LPNUAT.

CONCLUSIONS

LP characteristics such as disturbance of consciousness, hyponatremia, rhabdomyolysis, lobar consolidation, and less bronchial wall thickening and centrilobular nodule contribute to the diagnosis of LP in patients with negative UAT results.

Clinical Impact of N-Terminal Prohormone of Brain Natriuretic Peptide on Patients Hospitalized with Community-Acquired Pneumonia

BACKGROUND

Risk stratification is important for the management of community-acquired pneumonia (CAP). The present study aimed to investigate the clinical impact of N-terminal prohormone of brain natriuretic peptide (NT-proBNP) on prognosis and to identify clinical characteristics associated with NT-proBNP elevation in CAP patients.

METHODS

This retrospective study included patients hospitalized for CAP at a tertiary referral center and who underwent measurement plasma NT-proBNP levels. Based on 30-day mortality, patients (n = 1,821) were divided into 2 groups, survivors (n = 150) and nonsurvivors (n = 1,671), and clinical and laboratory findings were compared.

RESULTS

In multivariate analysis, blood levels of NT-proBNP (>942.5 pg/mL), albumin (<3.3 g/dL), and troponin I (>0.018 ng/mL) independently predicted 30-day mortality. Of these blood biomarkers, NT-proBNP exhibited the highest C-statistic, followed by albumin. NT-proBNP level/CURB-65 score and NT-proBNP level/pneumonia severity index (PSI) class exhibited significantly higher C-statistics than CURB-65 score and PSI class alone, respectively. The 3-test combinations of CURB-65 score/NT-proBNP level/albumin level and PSI class/NT-proBNP level/albumin level exhibited significantly higher C-statistics than the 2-test combinations. NT-proBNP elevation was associated with increased age, heart disease and chronic kidney disease and NT-proBNP levels only weakly or moderately correlated with other blood biomarkers.

CONCLUSIONS

NT-proBNP level was a useful marker for the prediction of 30-day mortality in patients hospitalized with CAP, and provided additional prognostic value to PSI or CURB-65 alone.

Burden of Community-Acquired Pneumonia and Unmet Clinical Needs

Community-acquired pneumonia (CAP) is the leading cause of death among infectious diseases and an important health problem, having considerable implications for healthcare systems worldwide. Despite important advances in prevention through vaccines, new rapid diagnostic tests and antibiotics, CAP management still has significant drawbacks. Mortality remains very high in severely ill patients presenting with respiratory failure or shock but is also high in the elderly. Even after a CAP episode, higher risk of death remains during a long period, a risk mainly driven by inflammation and patient-related co-morbidities. CAP microbiology has been altered by new molecular diagnostic tests that have turned viruses into the most identified pathogens, notwithstanding uncertainties about the specific role of each virus in CAP pathogenesis. Pneumococcal vaccines also impacted CAP etiology and thus had changed Streptococcus pneumoniae circulating serotypes. Pathogens from specific regions should also be kept in mind when treating CAP. New antibiotics for CAP treatment were not tested in severely ill patients and focused on multidrug-resistant pathogens that are unrelated to CAP, limiting their general use and indications for intensive care unit (ICU) patients. Similarly, CAP management could be personalized through the use of adjunctive therapies that showed outcome improvements in particular patient groups. Although pneumococcal vaccination was only convincingly shown to reduce invasive pneumococcal disease, with a less significant effect in pneumococcal CAP, it remains the best therapeutic intervention to prevent bacterial CAP. Further research in CAP is needed to reduce its population impact and improve individual outcomes.

Disease Burden and Etiologic Distribution of Community-Acquired Pneumonia in Adults: Evolving Epidemiology in the Era of Pneumococcal Conjugate Vaccines

Pneumonia is the leading cause of morbidity and mortality, particularly in old adults. The incidence and etiologic distribution of community-acquired pneumonia is variable both geographically and temporally, and epidemiology might evolve with the change of population characteristics and vaccine uptake rates. With the increasing prevalence of chronic medical conditions, a wide spectrum of healthcare-associated pneumonia could also affect the epidemiology of community-acquired pneumonia. Here, we provide an overview of the epidemiological changes associated with community-acquired pneumonia over the decades since pneumococcal conjugate vaccine introduction.