Five-year mortality in patients treated for severe community-acquired pneumonia - a retrospective study

Microplastics exposed by respiratory tract and exacerbation of community-acquired pneumonia: The potential influences of respiratory microbiota and inflammatory factors

The relationships between microplastics (MP) exposure through respiratory and exacerbation of community-acquired pneumonia (CAP), as well as the potential influences of respiratory microbiota and inflammatory factors remain unknown in adults. Therefore, we conducted a cross-sectional study involving 50 non-severe CAP (NSCAP) and severe CAP (SCAP) patients to examine the associations of MP exposure in sputum (SP) and bronchoalveolar lavage fluid (BALF) samples with SCAP risk, and the underlying influences of respiratory microbiota and inflammatory factors. The average concentration of total MP was 23.24 μg/g dw and 4.49 μg/g dw in SP and BALF samples, with the detection rates of 98 % and 94 %. Participants who performing housework often or sedentary time ≤ 5h exhibited a higher proportion of high exposure to MP. Multivariable logistic regression and weighted quantile sum regression models showed the significantly positive relationships of single type or overall MP exposure with SCAP risk. Correlation analysis revealed that MP concentrations in BALF samples were significantly associated with multiple respiratory microbiota and inflammatory factors, particularly with the reduction in α-diversity indices of the respiratory microbiota. Our findings demonstrated that respiratory exposure to MP may cause the risk increase of SCAP, along with the alterations of respiratory microbiota and inflammatory factors. It is recommended that patients with CAP should reduce the respiratory exposure to MP for preventing the exacerbation of CAP in clinical practice.

Clinical impact of bronchoalveolar lavage fluid metagenomic next-generation sequencing in immunocompromised patients with severe community-acquired pneumonia in ICU: a multicenter retrospective study

BACKGROUND

An increasing number of critically ill patients are immunocompromised. These patients are at high risk of intensive care unit (ICU) admission because of numerous complications. Acute respiratory failure due to severe community-acquired pneumonia (SCAP) is one of the leading causes of admission. Early targeted antibiotic therapy is crucial for improving the prognosis of these patients. Metagenomic next-generation sequencing (mNGS) in bronchoalveolar lavage fluid (BALF) has shown significant value in pathogen detection in recent years. However, there are few studies on summarizing pathogen profiles of SCAP in immunocompromised patients.

METHODS

We performed a multicenter retrospective analysis of patients with SCAP in the ICU diagnosed between May 2021 to October 2024. Bronchoalveolar lavage fluid (BALF), blood, and sputum samples were collected and subjected to mNGS and conventional microbiological tests (CMTs). The pathogen profiles detected by the two methods were compared.

RESULTS

In our study, compared to CMTs, mNGS increased the detection rates of mixed infections in the immunocompromised group (58.82% vs 17.96%, P < 0.05) and immunocompetent group (44.58% vs 18.72%, P < 0.05), while also reducing the rate of no pathogen detected (4.90% vs 38.73%, P < 0.05; 8.37% vs 32.76%, P < 0.05). In both groups, the proportion of positive clinical impacts (diagnosis) resulting from mNGS results exceeded 90% (96.57% vs 93.84%), and the treatment effectiveness rate in the immunocompromised group was higher than in the immunocompetent group (65.69% vs 56.40%, P < 0.05). Further analysis showed that when mNGS-guided treatment was effective, the 28-day mortality rate significantly improved in both the immunocompromised group (31.34% vs 74.29%, P < 0.05) and the immunocompetent group (42.36% vs 40.68%, P < 0.05) compared to when the treatment was ineffective.

CONCLUSION

This study indicates that ICU patients with SCAP, particularly those who are immunocompromised, are more likely to have polymicrobial infections. mNGS in BALF provides rapid and comprehensive pathogen profiling of pulmonary infections, thereby having a positive impact on both the diagnosis, treatment and prognosis of immunocompromised patients with SCAP.

Etiology of Severe Community Acquired Pneumonia in Adults Identified by Combined Detection Methods: A Multi-center Prospective Study in China

Severe Community Acquired Pneumonia (SCAP) challenges public health globally. Considerable improvements in molecular pathogen testing emerged in the last few years. Our prospective study combinedly used traditional culture, antigen tests, PCR and mNGS in SCAP pathogen identification with clinical outcomes. From June 2018 to December 2019, we conducted a multi-centre prospective study in 17 hospitals of SCAP patients within 48 hours of emergency room stay or hospitalization in China. All clinical data were uploaded into an online database. Blood, urine and respiratory specimens were collected for routine culture, antigen detection, PCR and mNGS as designed appropriately. Aetiology confirmation was made by the local attending physician group and scientific committee according to microbiological results, clinical features, and response to the treatment. Two hundred seventy-five patients were included for final analysis. Combined detection methods made identification rate up to 74.2% (222/299), while 14.4% (43/299) when only using routine cultures and 40.8% (122/299) when not using mNGS. Influenza virus (23.2%, 46/198), S. pneumoniae (19.6%, 39/198), Enterobacteriaceae (14.6%, 29/198), Legionella pneumophila (12.6%, 25/198), Mycoplasma pneumoniae (11.1%, 22/198) were the top five common pathogens. The in-hospital mortality of patients with pathogen identified and unidentified was 21.7% (43/198) and 25.9% (20/77), respectively. In conclusion, early combined detection increased the pathogen identification rate and possibly benefitted survival. Influenza virus, S. pneumoniae, Enterobacteriaceae was the leading cause of SCAP in China, and there was a clear seasonal distribution pattern of influenza viruses. Physicians should be aware of the emergence of uncommon pathogens, including Chlamydia Psittaci and Leptospira.

Impact of chronic obstructive pulmonary disease on mortality in community acquired pneumonia: a meta-analysis

Background: The aim of the present study was to systematically review the exiting literature and to proceed a meta-analysis to determine the impact of chronic obstructive pulmonary disease (COPD) on mortality in patients with community acquired pneumonia. Materials & methods: Eligible studies were searched from PubMed, Cochrane Library and EMBASE. Odds ratios (ORs) with 95% CIs were used as effect estimates. Results: Twenty cohort studies were included. Analysis of unadjusted data revealed nonsignificant short- and long-term mortality associated with COPD. Analysis of adjusted 30-days mortality showed similarly no association between COPD and increased 30-days mortality (OR: 1.06, [0.68, 1.44]) but a positive association when COPD was confirmed spirometrically (OR: 1.84, [1.06, 2.62]). Conclusion: There is still no evidence to clear the impact of COPD on mortality in patients with community acquired pneumonia. More prospective studies with spirometrically-defined COPD and adequate adjustment for confounders are needed.

Mortality from infectious diseases in diabetes

BACKGROUND AND AIMS

To investigate the risk of mortality from infections by comparing the underlying causes of death versus the multiple causes of death in known diabetic subjects living in the Veneto region of Northern Italy.

METHODS AND RESULTS

A total of 185,341 subjects with diabetes aged 30-89 years were identified in the year 2010, and causes of death were assessed from 2010 to 2015. Standardized Mortality Ratios (SMRs) with 95% confidence intervals (CIs) were computed with regional mortality rates as reference. The underlying causes of death and all the diseases reported in the death certificates were scrutinized. At the end of the follow-up, 36,382 subjects had deceased. We observed an increased risk of death from infection-related causes in subjects with diabetes with a SMR of 1.83 (95% CI, 1.71-1.94). The SMR for death from septicemia was 1.91 (95% CI, 1.76-2.06) and from pneumonia was 1.47 (95% CI, 1.36-1.59). The use of the multiple causes of death approach emphasized the association of infectious diseases with mortality.

CONCLUSION

The results of the present study demonstrate an excess mortality due to infection-related diseases in patients with diabetes; more interestingly, by routine mortality analyses, the results show a possible underestimation of the effect of these diseases on mortality.

Acute respiratory distress syndrome in mechanically ventilated patients with community-acquired pneumonia

Our aim was to assess the incidence, characteristics, aetiology, risk factors and mortality of acute respiratory distress syndrome (ARDS) in intensive care unit (ICU) patients with community-acquired pneumonia (CAP) using the Berlin definition.We prospectively enrolled consecutive mechanically ventilated adult ICU patients with CAP over 20 years, and compared them with mechanically ventilated patients without ARDS. The main outcome was 30-day mortality.Among 5334 patients hospitalised with CAP, 930 (17%) were admitted to the ICU and 432 required mechanical ventilation; 125 (29%) cases met the Berlin ARDS criteria. ARDS was present in 2% of hospitalised patients and 13% of ICU patients. Based on the baseline arterial oxygen tension/inspiratory oxygen fraction ratio, 60 (48%), 49 (40%) and 15 (12%) patients had mild, moderate and severe ARDS, respectively. Streptococcus pneumoniae was the most frequent pathogen, with no significant differences in aetiology between groups. Higher organ system dysfunction and previous antibiotic use were independent risk factors for ARDS in the multivariate analysis, while previous inhaled corticosteroids were independently associated with a lower risk. The 30-day mortality was similar between patients with and without ARDS (25% versus 30%, p=0.25), confirmed by propensity-adjusted multivariate analysis.ARDS occurs as a complication of CAP in 29% of mechanically ventilated patients, but is not related to the aetiology or mortality.