Introduction: Lung cancer is the most prevalent cancer with high mortality in China, and it is associated with the dysbiosis of the lung microbiome. This study attempted to screen for specific microorganisms as potential biomarkers for distinguishing benign lung disease from lung cancer.Methods: Bronchoalveolar lavage fluid (BALF) sample was selected in the study instead of saliva to avoid contamination with oral microorganisms, and microbial taxonomic and functional differences in BALF samples from patients with lung cancer and those with those from patients with benign lung diseases were performed based on metagenomic next‐generation sequencing, for the first time, so that microorganisms other than bacteria could be included.Results: The results showed that the intrasample diversity of malignant samples was different from benign samples, and the microbial differences among malignant samples were smaller, with lower microbial diversity, significantly changed microbial abundance and metabolic functions. Metabolic function analysis revealed amino acid‐related metabolism was more prevalent in benign samples, whereas carbohydrate‐related metabolism was more prevalent in malignant samples. By LEfSe, Metastat and Random Forest analysis, we identified a series of important differential microorganisms. Importantly, the model combining five key genera plus one tumor marker (neuron‐specific enolase) as indicators presented the optimal disease typing performance.Conclusion: Thus results suggest the value of these differential microorganisms enriched in tumors in mechanism research and may be potential new targets for lung cancer therapy. More importantly, the biomarkers identified in this study can be conducive to improve the clinical diagnosis of lung cancer and have good application prospects.

Patient concerns: A 70-year-old man with a primary tracheal adenoid cystic carcinoma (TACC) located at 5 cm of the tracheal process. Interventions: We adopted bronchoscopic ablation technology, including cryotherapy of probe tumor reduction and thermal ablation, which lasted for 7 years. After that, flexible mechanical tumor reduction was used to remove the tumor, and para-toluenesulfonamide (PTS) was injected to treat any residual tumors. During the treatment, we found that scarring-induced stenosis of the trachea near the superior aspect of the tumor, under these circumstances, we performed bronchoscopic laser treatment to remove scar tissue and relieve central airway obstruction. Outcomes: The combined use of bronchoscopic laser treatment and PTS injection represents a promising treatment, especially suitable for patients who are not suitable for surgical removal. This case highlights the importance of individualized treatment strategies in managing complex airway obstruction, improving the quality of life of patients, and providing symptom relief for patients with advanced tumors.

Background: Malignant central airway obstruction (MCAO) is a severe complication of advanced thoracic malignancies. Bronchoscopic intervention combined with intralesional para-toluenesulfonamide (PTS) injection can restore airway patency, but local mucosal inflammation after treatment may cause pain, edema, and poor early tolerability. This study assessed whether local methylprednisolone irrigation after PTS-based bronchoscopic treatment improves short-term outcomes in patients with MCAO. Methods: We retrospectively analyzed 88 treatment sessions from 35 consecutive patients who underwent bronchoscopic intervention plus intralesional PTS injection between January 2024 and December 2025. According to the irrigation solution used after PTS injection, sessions were divided into methylprednisolone and normal saline groups. Outcomes at 72 h included cough score, mMRC dyspnea score, airway stenosis score, pain score, mucosal edema, and bleeding. Linear mixed-effects models and generalized estimating equations were used to account for repeated treatment sessions, and inverse probability of treatment weighting was applied to adjust for baseline differences. Results: Bronchoscopic intervention plus PTS injection significantly improved cough, dyspnea, and airway stenosis at 72 h. Compared with normal saline, methylprednisolone irrigation did not provide additional improvement in these short-term efficacy outcomes. However, methylprednisolone irrigation was associated with lower post-procedural pain and less mucosal edema, without increasing bleeding risk. These findings remained consistent after weighting, sensitivity analyses, and false discovery rate correction. Conclusion: Local methylprednisolone irrigation after PTS-based bronchoscopic treatment may improve early procedural tolerability in patients with MCAO by reducing post-procedural pain and mucosal edema, rather than enhancing short-term airway-opening efficacy. Further prospective studies are needed to confirm these findings.

LAR, a composite biomarker reflecting metabolic stress and systemic inflammatory status, has demonstrated prognostic value across various critical illnesses. However, its clinical significance among critically ill adults with asthma diagnoses remains poorly defined. This study aimed to evaluate the association between LAR and mortality risk in ICU patients with asthma diagnoses and to develop and externally validate a LAR-based predictive model. We retrospectively analyzed 1,038 adult ICU patients with asthma diagnosis codes from the MIMIC-IV (v3.1) database (2008–2022) and 467 patients from the eICU-CRD for external validation. Asthma was identified using ICD diagnosis codes; therefore, the cohort represents critically ill patients with recorded asthma diagnoses rather than patients confirmed to have been admitted primarily for acute asthma exacerbation. LAR was calculated using admission laboratory values, with patients stratified by the median LAR (0.5385). Multivariable Cox regression, restricted cubic spline (RCS) analysis, and Kaplan-Meier curves were employed to assess mortality risks. Subgroup analyses were performed to evaluate consistency across clinical strata, adjusting for demographics, comorbidities, and clinical severity scores. In the discovery cohort, 28-day and 60-day mortality rates were 17.5% and 20.9%, respectively, with significantly higher rates observed in the high LAR group (P < 0.001). After multivariable adjustment in Cox models, each 1-unit increase in LAR was associated with 28-day (HR = 1.22, P = 0.002) and 60-day (HR = 1.16, P < 0.001) mortality. In the eICU-CRD validation cohort, where the available endpoint was ICU mortality, LAR was associated with ICU mortality in logistic regression (OR = 1.454, P = 0.012). Restricted cubic spline analysis did not provide evidence of a non-linear association between LAR and 28-day mortality. A gender interaction was identified for 28-day mortality (P interaction = 0.044), showing a stronger association in females. The final predictive model demonstrated good discrimination for ICU mortality in the eICU-CRD cohort, with an AUC of 0.809. Elevated LAR at ICU admission was associated with mortality in ICU patients with asthma diagnoses. The external eICU-CRD analysis supported the direction of this association for ICU mortality, although it used a different endpoint and modeling approach from the MIMIC-IV time-to-event analyses. These findings suggest that LAR may be an accessible risk-stratification marker, but prospective validation with harmonized mortality endpoints is required before clinical implementation.

Objective: To investigate pathogen distribution, clinical characteristics, and factors associated with lower respiratory tract multidrug-resistant organism (MDRO) isolation in patients with infectious pneumonia, and to develop an exploratory prediction-oriented nomogram. Methods: We retrospectively analyzed 117 patients with infectious pneumonia at Tianjin Chest Hospital from September 2024 to September 2025. Bacterial culture was positive in 102 patients. Patients were divided into an MDRO group ( n = 38) and a non-MDRO group ( n = 79; 64 with non-MDRO isolates and 15 culture-negative). Pathogen culture, identification, and susceptibility testing were performed. Clinical features were compared, and univariate and binary logistic regression identified factors associated with MDRO isolation. A prediction-oriented nomogram excluding length of RICU stay was developed and internally validated using ROC and calibration curves and 1000 bootstrap resamples. Results: MDRO isolation occurred in 38 patients: 37.25% (38/102) of culture-positive and 32.48% (38/117) of all enrolled patients. After deduplication, 81 MDRO isolates were identified; 75.31% were Gram-negative and 24.69% Gram-positive. The most common MDROs were Klebsiella pneumoniae (57.89%), Pseudomonas aeruginosa (42.11%), and Acinetobacter baumannii (34.21%); Gram-positive MDROs occurred in 9 patients (23.68%), mostly Staphylococcus aureus (21.05%). The MDRO group had longer RICU stays, higher rates of diabetes, hypoproteinemia, invasive mechanical ventilation, and combined antimicrobial therapy, and lower Glasgow Coma Scale (GCS) scores (all P < 0.05). Binary logistic regression identified diabetes (adjusted odds ratio [aOR] = 2.119), invasive mechanical ventilation (aOR=2.849), combined antimicrobial therapy (aOR=2.492), and prolonged RICU stay (aOR=1.137) as associated with MDRO isolation; higher GCS score (aOR=0.674) was associated with lower odds (all P < 0.05). The nomogram showed an apparent AUC of 0.862 (95% CI: 0.793–0.931), sensitivity 82.4%, specificity 87.8%, and an optimism-corrected AUC of 0.831 after 1000 bootstrap resamples. Calibration was acceptable (Brier score=0.142, intercept=−0.02, slope=0.88), with some underestimation at intermediate and overestimation at higher predicted probabilities. Conclusion: MDRO isolation is common in infectious pneumonia, predominantly Gram-negative bacteria. Diabetes, invasive mechanical ventilation, combined antimicrobial therapy, and prolonged RICU stay were associated with MDRO isolation, while higher GCS score was associated with lower odds. An exploratory prediction-oriented nomogram incorporating these factors was constructed but requires prospective validation.