Mucopolysaccharidosis (MPS) is a group of inherited lysosomal storage disorders associated with difficult airway management. Critical tracheal compression from an anterior mediastinal mass presents an additional challenge during interventional bronchoscopy, when the airway is shared by the ventilation and procedural devices. A 33-year-old woman with MPS (height, 100 cm; weight, 21.5 kg) and progressive dyspnea had a 50 × 22 mm anterior mediastinal mass and severe tracheal stenosis, with minimum luminal dimensions of approximately 13 × 1 mm. Bronchoscopic intervention was performed under general anesthesia using a laryngeal mask airway (LMA) and jet ventilation. Desaturation during normal-frequency jet ventilation (NFJV) resolved after superimposed high-frequency jet ventilation (SHFJV) was initiated. A 14-mm covered tracheal stent was removed because it was disproportionate to the patient’s airway, and balloon dilatation reduced the residual stenosis to approximately 70

Objective: To address the critical impact of smoke inhalation lung injury on burn patient prognosis and the lack of animal models simulating varying injury severity, we established a graded rat model to facilitate research into its pathological mechanisms and treatments. Methods: Eighteen male Wistar rats were divided into a control group and groups exposed to smoke for 5, 10, 15, 30 minutes (n=3 per group). A custom smoke chamber and specific materials (50 g pine wood chips + 10 mL kerosene) were used. Post-exposure assessments included lung function, lung coefficient (wet weight), histopathology (H&E staining), and leukocyte count and IL-6 levels in alveolar lavage fluid. Results: Lung function declined significantly in all exposure groups versus controls, with progressive worsening over time. The lung coefficient increased significantly in the 15- and 30-minute groups. Histology revealed intact structure at 5 and 10 minutes, alveolar rupture and neutrophil infiltration at 15 minutes, and hyaline membranes at 30 minutes. Leukocyte count and IL-6 levels rose markedly after 15 and 30 minutes of exposure. Statistical comparisons confirmed progressive injury severity with longer exposure. Conclusions: Graded rat models of mild, moderate, and severe inhalation lung injury were successfully established following 5, 15, and 30 minutes of smoke exposure, respectively. Injury and inflammation intensified significantly with exposure duration, providing a valuable foundation for further research.

The molecular distinction between benign and malignant pulmonary nodules remains a significant diagnostic challenge. While genomic drivers are well studied, multiomic integration of the epigenetic–transcriptional landscape and its translation into noninvasive tools are lacking. We performed a multiomic characterization (genomic, epigenomic, and transcriptomic) of 158 pulmonary nodules. Unsupervised factor analysis integrated these layers to identify core regulatory axes. A 9-gene cell-free DNA (cfDNA) methylation classifier was developed and validated in blood and tissue cohorts. Genomic profiling revealed EGFR mutations (exclusive to malignant nodules) and MYC amplification as fundamental initiators of malignancy. Multiomic factor analysis (Factor 1) revealed profound genetic‒epigenetic synergy, in which these alterations dictate a permissive methylome, leading to aberrant epigenetic programming of chromatin accessibility, as well as epigenetic-transcriptional effects: hypomethylation at the promoters of cell cycle genes that augments their expression, and hypermethylation at immune related pathways gene loci that silences their transcription. This effect orchestrates formation of proproliferative (E2F target/G2M checkpoint) and “immune-cold” malignant phenotype, characterized by elevated Treg/CD8+ ratios and fibroblast recruitment. Notably, we observed a gradual accumulation of methylation aberrations along the premalignant-to-invasive continuum (adenocarcinoma in situ [AIS]→minimally invasive adenocarcinoma [MIA]→adenocarcinoma [ADC]), identifying progressive epigenetic dysregulation as a hallmark of tumor aggressiveness. Global methylome remodeling drives ADC progression through hypermethylation-mediated silencing of tumor suppressors (RASA3 and PPARG) and hypomethylation-activated oncogenic axes, specifically the GDF15 axis, which independently predict poor survival in patients with lung ADC in the TCGA cohort. We translated these tissue-derived insights into a 9-gene cfDNA methylation classifier, which achieved exceptional diagnostic accuracy across independent cohorts (training AUC = 1.00; test AUC = 0.93; tissue AUC = 0.96). Rooted in the biological “ground truth” of tissue dysregulation, this classifier functions specifically as a functional readout of the core cell cycle and proliferative pathways, offering a robust, noninvasive tool for the biology-informed risk assessment of pulmonary nodules. This study delineates an epigenetic–transcriptional regulatory network that drives nodule malignancy. Our findings provide a robust theoretical foundation and a high-performance liquid biopsy tool for the precise, noninvasive diagnosis of pulmonary nodules.

BACKGROUND:Benign airway stenosis (BAS) involves progressive pathological narrowing of the trachea and main bronchi, causing clinically significant respiratory impairment that can advance to life-threatening obstruction. While fibrosis arises from dysregulated immune-stromal crosstalk, the specific cellular and molecular drivers of BAS remain poorly understood. METHODS:We conducted single-cell RNA sequencing on clinical specimens representing the BAS spectrum normal airway, granulation tissue, and fibroproliferative tissue. Integrated bioinformatic analyses delineated cellular heterogeneity, intercellular communication, and differentiation trajectories. Spatial validation of key subsets was performed using multiplex immunofluorescence. Functional assessment of the PROS1-AXL axis involved treating primary human airway granulation fibroblasts (PHAGF) isolated from BAS patients with either conditioned medium from RANKL-stimulated THP-1 macrophages or recombinant PROS1, followed by inhibition with the AXL-specific antagonist R428. In parallel, an in vivo mouse model of BAS was used to evaluate the therapeutic efficacy of R428. RESULTS:Transcriptomic analysis revealed substantial remodeling of the BAS microenvironment, marked by epithelial depletion and expansion of stromal and immune compartments. We identified a novel macrophage subset co-expressing CTSK and SLC9B2, specifically enriched in granulation tissue. Communication analysis demonstrated selective PROS1-AXL signaling between CTSK+ macrophages and CD82+ fibroblasts. Pseudotemporal analysis positioned this crosstalk upstream of myofibroblast differentiation. Multiplex immunofluorescence confirmed CTSK+ macrophage localization in human BAS granulation tissue. In vitro, conditioned medium from RANKL-primed THP-1 macrophages promoted fibroblast activation in PHAGF cells through the PROS1-AXL axis, an effect that was attenuated by AXL inhibition with R428. Furthermore, Western blot analysis revealed that PROS1-AXL signaling activated the AKT/GSK3β pathway in PHAGF cells. In vivo, systemic administration of R428 in a BAS mouse model significantly reduced fibrotic remodeling, as evidenced by decreased granulation tissue hyperplasia, collagen deposition, and improved survival compared to vehicle-treated controls. Furthermore, TNFSF11 on CD82+ fibroblasts may bind TNFRSF11A on CTSK+ macrophage precursors to drive their differentiation. CONCLUSION:This work defines a pro-fibrotic cellular module in BAS CTSK+ macrophages and CD82+ fibroblasts interacting via PROS1-AXL and establishes a rationale for targeting this pathway, supported by both patient-relevant primary cell and in vivo evidence, to disrupt fibrosis and mitigate recurrence.

BACKGROUND:Checkpoint inhibitor pneumonitis (CIP) is the leading cause of treatment-related deaths for immune checkpoint inhibitor (ICI) combination therapies. CIP is problematic to diagnose and differentiate, particularly from radiation pneumonitis (RP), due to the lack of mechanistic distinctions between them. METHODS:Using single-cell RNA sequencing (scRNA-seq) and single-cell T cell receptor sequencing (scTCR-seq), we characterize the cellular landscape of bronchoalveolar lavage fluid (BALF) and peripheral blood from a discovery cohort (seven CIP, six RP, and six treatment-naive controls) and a validation cohort (five patients receiving combined ICI and radiotherapy who were diagnosed with RP). FINDINGS:We report a striking accumulation of alveolar CD8+ exhausted T cells (Texs) in CIP. The alveolar CD8+ Texs of CIP primarily differentiate from tissue-resident ZNF683hi CD8+ T cells, whereas those of RP predominantly originate from peripherally related GZMKhi CD8+ T cells. These findings were further validated in a prospectively enrolled validation cohort and ultimately guided successful clinical decisions regarding ICI rechallenge. CONCLUSIONS:These results highlight distinct cellular and molecular features in CIP and RP, thereby providing insights into clinical decision-making regarding ICI rechallenge in lung cancer patients. FUNDING:This study was supported by the National Natural Science Foundation of China.

BACKGROUND:The potential role of the iroquois homeobox (IRX) genes in tumorigenesis is a subject of interest, yet their specific involvement in lung adenocarcinoma (LUAD) has not been extensively examined. OBJECTIVE:This research endeavored to explore the impact of the IRX genes on the onset and progression of LUAD. METHODS:Utilizing data from The Cancer Genome Atlas (TCGA), samples of LUAD were selected for analysis. The influence of the IRX genes was scrutinized through various tools, including Kaplan-Meier Plotter, cBioPortal, and the R programming language (version 3.6.3), with gene expression levels being confirmed in cellular models via quantitative real-time polymerase chain reaction (qRT-PCR). RESULTS:It was observed that the levels of IRX1/2/3/6 were notably diminished in LUAD tissues when juxtaposed with healthy lung tissue. Conversely, the expression of IRX4 was found to be elevated in LUAD. Correlations were identified between IRX gene expression and several clinical parameters such as T stage, smoking history quantified in pack-years, lymph node involvement, patient gender, initial treatment responses, and smoking status. The diminished expression of IRX2/5 emerged as a significant indicator of an unfavorable prognosis in LUAD. The study also highlighted the potential of various IRX genes as diagnostic indicators for LUAD. These genes were implicated in the facilitation of LUAD's growth and spread through a range of biological pathways, encompassing the Ras signaling and more. Additionally, a pronounced link was discovered between the infiltration of immune cells and the expression patterns of the IRX genes. IRX genes were abnormally expressed in LUAD cell lines. CONCLUSION:IRX gene family could serve not only as indicators of LUAD prognosis but also as therapeutic targets for LUAD.

BACKGROUND:A novel airway balloon cryoablation (ABC) system using liquid nitrogen as cryogen was developed for bronchoscopic intervention in malignant central airway obstruction (MCAO). This study aimed to evaluate the efficacy and safety of this system. METHODS:This was a prospective, randomised, controlled, non-inferiority study that enrolled MCAO patients at 15 sites in China. Patients were assigned to the ABC group and the ERBOKRYOCA Cryosurgical (EC) system group in a 1:1 ratio. Airway tumour debulking with multimodality was permitted before cryoablation. The primary outcome was the airway patency rate after 6 weeks of intervention with a non-inferiority margin of -10%. Secondary outcomes included modified Medical Research Council (mMRC) Dyspnoea Scale and Karnofsky Performance Scale (KPS) assessment, and the duration of cryoablation. RESULTS:198 patients were randomised. After 6 weeks of intervention, the airway patency rate was 78.49% in the ABC group and 60.92% in the EC group, showing that the difference was over the non-inferiority margin of -10% at 17.58% (95% CI 4.35% to 30.80%), p<0.001. The mMRC and KPS scores were significantly improved after 3 and 6 weeks in both groups, with no difference. The duration of cryoablation was shortened remarkably in the ABC group (378.29±399.54 s vs 624.93±443.72 s, p<0.001). The prevalence of bleeding was similar in the two groups, without life-threatening events. CONCLUSIONS:The ABC system provided non-inferior and subsequent superior effect in airway patency rate compared with traditional carbon dioxide-driven cryoprobe in MCAO. This study supports this novel system as an alternative to cryoablation via bronchoscope for MCAO patients. TRIAL REGISTRATION NUMBER:ChiCTR2100042051.

BACKGROUND:Envafolimab is a novel immune checkpoint inhibitor (ICI) with several advantages due to its subcutaneous administration. Phases I and II randomized controlled trials have demonstrated promising efficacy in treating colorectal and gastric cancer. However, the safety and efficacy of Envafolimab in patients with advanced lung cancer remain to be investigated. METHODS:This retrospective, multicenter, open-label, single-arm cohort study examined real-world medical data from patients treated at four medical centers to assess the safety and efficacy of Envafolimab in treating patients with advanced lung cancer. The primary safety outcome was Envafolimab-related treatment-emergent adverse events (TEAEs) and immune-related adverse events (irAEs). The primary efficacy outcomes included overall survival (OS) and progression-free survival (PFS). Then, the relationship between clinical parameters and prognosis was investigated using univariate and multivariate regression analyses. Furthermore, the impact of tumor EGFR driver mutation status and PD-L1 expression on prognosis was explicitly explored in patients with nonsmall-cell lung cancer (NSCLC). RESULTS:The cohort comprised 58 patients with a median follow-up time of 8.3 months (from March 1, 2022, to March 7, 2024). Envafolimab-related TEAEs and irAEs were observed in 53.4% and 27.6% of patients, respectively. No specific clinical factors were identified as being associated with irAEs. The median OS was 8.5 months (95% confidence interval [CI] 6.2-10.8), and the median PFS was 6.1 months (95% CI 3.8-8.3). For 47 patients with NSCLC, factors including ECOG PS > 2 (HR: 2.91, p = 0.015), Stage IV tumor (HR: 3.43, p = 0.043), and nonfirst-line Envafolimab treatment (HR: 3.27, p = 0.026) were associated with poor prognosis. CONCLUSION:Envafolimab demonstrates a tolerable safety profile and favorable efficacy. With its subcutaneous formulation, Envafolimab shows promising potential for treating advanced lung cancer.

The tracheal stent is one of the treatment modalities for tracheal stenosis. However, the mismatch of mechanical properties between the tracheal stent and the trachea may lead to stent migration. The aim of this study is to design a tracheal stent with J-shaped load–deformation behavior based on a multi-objective optimization method. Four design parameters were selected as optimization variables. The optimization objectives were the loads at 5

Tracheobronchopathia osteochondroplastica (TO) is an uncommon non‐malignant tracheal ailment characterized by the existence of numerous bone and/or cartilage nodules in the submucosa of the trachea and bronchi. At present, there is a lack of standardized treatment recommendations for TO. This article presents two instances of severe tracheal stenosis caused by TO, which were effectively managed through the implementation of bronchoscopic stent placement and rigid bronchoscopy curettage, respectively. Both cases exhibited favorable outcomes, providing novel insights and references for the treatment of TO. Laryngoscope , 134:3093–3095, 2024

Background Expiratory central airway collapse (ECAC) following postintubation airway stenosis (PITS) is a rare phenomenon. The impact of airway malacia and collapse on the prognosis and the success rate of bronchoscopic interventional therapy in patients with PITS had been inadequately investigated. Objective The aim of this research was to assess the influence of airway malacia and collapse on the efficacy of bronchoscopic interventional therapy in patients with PITS. Design This retrospective analysis examined the medical documentation of individuals diagnosed with PITS who underwent bronchoscopic intervention at the tertiary interventional pulmonology center of Emergency General Hospital from 2014 to 2021. Main outcome measures Data pertaining to preoperative, perioperative, and postoperative stages were documented and subjected to analysis. Results The patients in malacia and collapse group (MC group) exhibited a higher frequency of perioperative complications, including intraoperative hypoxemia, need for reoperation within 24 h, and postoperative intensive care unit admission rate (P < 0.05, respectively). Meanwhile, patients in group MC demonstrated significantly worse postoperative scores (higher mMRC score and lower KPS score) compared to those in pure stenosis group (P < 0.05, respectively), along with higher degrees of stenosis after treatment and a lower success rate of bronchoscopic intervention therapy cured (P < 0.05, respectively). Pearson analysis results showed that these terms were all significantly correlated with the occurrence of airway malacia and collapse in the airway (P < 0.05, respectively). Conclusion The presence of malacia or collapse in patients with PITS was associated with increased perioperative complications following bronchoscopic interventional therapy, and significantly reduced the long-term cure rate compared to patients with pure tracheal stenosis. Trial registration Chinese Clinical Trial Registry on 06/12/2021. Registration number: ChiCTR2100053991.

Objective:With advancements in respiratory interventional techniques, bronchoscopic intervention technology has emerged as a viable approach for managing postintubation tracheal stenosis (PITS). However, there was a paucity of research investigating the potential impact of stenosis characteristics and morphology (such as stenosis degree, length, type, and morphology) on bronchoscopic intervention treatment prognosis for PITS patients. This study was to assess the impact of various preoperative stenosis characteristic factors on the bronchoscopic cure rate among patients. Methods:This is a retrospective study analyzing the medical records of patients with PITS who received bronchoscopic intervention at the tertiary interventional pulmonology center. Results:Among the cases, 115 individuals achieved a in a success rate of 79.86% for bronchoscopic intervention therapy and were assigned to Group S. On the other hand, 29 cases required surgical intervention, accounting for a surgical treatment rate of 20.14% and were assigned to Group F. The stenosis in the Group F predominantly exhibited irregular shapes with scar granulation accompanied by tracheal chondromalacia collapse. Patients in group S experienced fewer total procedures, rigid bronchoscopy treatment, intraoperative hypoxemia, needed emergency re-bronchoscopy in 24 h and transferred to ICU postoperatively. Patients with pure scar and granuloma, the rate of bronchoscopic success cure was higher than patients with scar granulation accompanied by tracheal chondromalacia (odds ratio: 8.208; 95% confidence interval: 2.755-24.459), and regular stenosis morphology was associated with a higher bronchoscopic success cure rate (odds ratio: 9.463; 95% confidence interval: 3.128-28.623). Conclusion:Irregular airway stenosis, chondromalacia or airway collapse are key factors affecting the success rate of bronchoscopic treatment for post-intubation tracheal stenosis. Level of evidence: 4 (historically controlled studies).

Malignant central airway stenosis is treated with airway stent placement, but post-placement microbial characteristics remain unclear. We studied microbial features in 60 patients post-stent placement, focusing on changes during granulation tissue proliferation. Samples were collected before stent (N = 29), after stent on day 3 (N = 20), and after granulation tissue formation (AS-GTF, N = 43). Metagenomic sequencing showed significant respiratory tract microbiota changes with granulation tissue. The microbiota composition, dominated by Actinobacteria, Firmicutes, and Proteobacteria, was similar among the groups. At the species level, the AS-GTF group exhibited significant differences, with Peptostreptococcus stomatis and Achromobacter xylosoxidans enriched. Analysis based on tracheoesophageal fistula presence identified Tannerella forsythia and Stenotrophomonas maltophilia as the main differential species, enriched in the fistula subgroup. Viral and fungal detection showed Human gammaherpesvirus 4 and Candida albicans as the main species, respectively. These findings highlight microbiota changes after stent placement, potentially associated with granulation tissue proliferation, informing stent placement therapy and anti-infective treatment optimization. IMPORTANCE:Malignant central airway stenosis is a life-threatening condition that can be effectively treated with airway stent placement. However, despite its clinical importance, the microbial characteristics of the respiratory tract following stent insertion remain poorly understood. This study addresses this gap by investigating the microbial features in patients with malignant central airway stenosis after stent placement, with a specific focus on microbial changes during granulation tissue proliferation. The findings reveal significant alterations in the diversity and structure of the respiratory tract microbiota following the placement of malignant central airway stents. Notably, certain bacterial species, including Peptostreptococcus stomatis and Achromobacter xylosoxidans, exhibit distinct patterns in the after-stent granulation tissue formation group. Additionally, the presence of tracheoesophageal fistula further influences the microbial composition. These insights provide valuable references for optimizing stent placement therapy and enhancing clinical anti-infective strategies.

Acquired digestive-respiratory tract fistulas occur with abnormal communication between the respiratory tract and digestive tract caused by a variety of benign or malignant diseases, leading to the alimentary canal contents in the respiratory tract. Although various departments have been actively exploring advanced fistula closure techniques, including surgical methods and multimodal therapy, some of which have gotten good clinical effects, there are few large-scale evidence-based medical data to guide clinical diagnosis and treatment. The guidelines update the etiology, classification, pathogenesis, diagnosis, and management of acquired digestive-respiratory tract fistulas. It has been proved that the implantation of the respiratory and digestive stent is the most important and best treatment for acquired digestive-respiratory tract fistulas. The guidelines conduct an in-depth review of the current evidence and introduce in detail the selection of stents, implantation methods, postoperative management and efficacy evaluation.

目的 分析表现为慢性咳嗽的青年原发性气管腺样囊性癌误诊原因及防范措施.方法 回顾性分析2010 年1 月—2022 年10 月以慢性咳嗽为主要表现青年原发性气管腺样囊性癌4 例的临床资料.结果 本组均因慢性咳嗽就诊,干咳4 例,气喘2 例,喘憋1 例,活动后呼吸困难1 例.误诊为慢性支气管炎 2 例、支气管哮喘 2 例.误诊时间0.5～2.0 年.4 例给予抗感染、止咳、平喘等治疗效果不理想,经支气管镜活组织病理检查后确诊为原发性气管腺样囊性癌.确诊后均给予支气管镜介入治疗,未行外科手术治疗.随访时间 1～12 年,2 例病情稳定,另外 2 例分别在患病第4 年、第12 年复发,病变范围增大,气道狭窄显著,且伴双肺多发转移灶,目前正在接受支气管镜介入治疗,病情稳定.结论 表现为慢性咳嗽的青年原发性气管腺样囊性癌临床及胸部影像学表现不典型,容易误诊.及时行颈段联合胸段CT及支气管镜检查可以早期明确诊断,从而减少误诊及误治.支气管镜下的综合治疗有助于改善患者的临床症状,延长生存时间.

目的 探讨气道金属覆膜支架置入治疗恶性食管气管瘘的疗效及安全性.方法 2018年1月-2022年9月应急总医院诊治恶性食管气管瘘患者52例,均给予气道金属覆膜支架置入治疗,比较治疗前及治疗1个月时临床症状(呛咳、咳嗽、咳痰、发热)、实验室指标(白细胞计数、中性粒细胞绝对值、C反应蛋白、白蛋白、血红蛋白)、KPS评分、气促评分.随访2～60个月,观察瘘口封堵情况、支架置入治疗相关并发症发生情况及患者生存情况.结果 52例患者治疗1个月时呛咳、咳嗽、咳痰、发热发生率(5.8％、42.3％、13.5％、1.9％)及白细胞计数[(7.24±4.04)×109/L]、中性粒细胞绝对值[(5.71±4.46)×109/L]、血清 C 反应蛋白水平[(42.94±6.50)mg/L]均低于治疗前[88.5％、96.2％、73.1％、36.5％、(9.55±5.50)×109/L、(8.11±5.76)X 109/L、(78.03±8.87)mg/L](P＜0.05),白蛋白[(33.20±4.30)g/L]、血红蛋白[(108.30±18.30)g/L]水平均高于治疗前[(31.20±4.20)、(103.40±15.50)g/L](t=-3.084,P＜0.001;t=-3.000,P=0.004);治疗 1 个月时 KPS 评分[70(70,80)分]高于治疗前[60(50,70)分](Z=-6.465,P＜0.001),气促评分[1.5(1,2)分]低于治疗前[2.5(2,3)分](Z=-6.833,P＜0.001).末次随访时,52例患者中瘘口完全缓解1例,临床完全缓解49例,部分缓解2例;支架相关并发症为分泌物潴留(+)17例,(++)27例,(+++)8例;肉芽增生(+)～(++)45例,(+++)～(++++)7例;Ⅰ形支架移位3例,Y形支架均未发生移位;生存期为(12.8±2.7)个月,中位生存期为(6.0±1.2)个月.结论 气道金属覆膜支架置入治疗恶性食管气管瘘可有效改善患者临床症状,提高生存质量,延长生存时间,安全性好.

Airway stenting is an important clinical intervention applied in patients with airway disorders, but it may change the microbial composition of the airways. Before the placement of stents for benign and malignant airway stenosis, the predominant microbiota in the airway is Staphylococcus aureus, while after stent placement, the microbial spectrum change to gram-negative bacteria. Additionally, there is a close relationship between stent-related infection and granulation tissue growth with Staphylococcus aureus and Pseudomonas aeruginosa.

Abstract Background The current concept of bronchoscopy-associated massive airway hemorrhage is not accurate enough, and the amount of bleeding as the only evaluation criterion cannot comprehensively evaluate magnitude of the effects and the severity. Objective To propose the concept of bronchoscopy-associated acute massive airway hemorrhage, analyze its impact on patients and highlight the treatment approach of acute massive airway hemorrhage without ECMO support. Designs A retrospective cohort study. Setting Include all patients who received bronchoscopy intervention therapy at Interventional Pulmonology Center of Emergency General Hospital from 2004 to December 2021. Patients 223 patients met the inclusion criteria. Intervention Patients were divided into two groups: acute massive airway hemorrhage group (n = 29) and non-acute massive airway hemorrhage group (n = 194). Main outcome measures Perioperative adverse events between two groups were the main outcome. Secondary outcome was the impact of lung isolation on patient in group Acute. Results The incidence of acute massive airway hemorrhage was 0.11%, and the incidence of non-acute massive airway hemorrhage was 0.76% in this study. There were significant differences in the incidence of intraoperative hypoxemia, lowest SpO2, hemorrhagic shock, cardiopulmonary resuscitation, intraoperative mortality, and transfer to ICU between acute group and non-acute group (P<0.05, respectively). Lung isolation was used in 12 patients with acute massive airway hemorrhage, and only 2 patients died during the operation. Conclusion Bronchoscopy-associated acute massive airway hemorrhage had more serious impact on patients due to rapid bleeding, blurred vision of bronchoscopy, inability to stop bleeding quickly, blood filling alveoli, and serious impact on oxygenation of the lung lobes. Polyvinyl chloride single-lumen endotracheal intubation for lung isolation, with its characteristics of low difficulty, wide applicability and available in most hospitals, may reduce the intraoperative mortality of patients with bronchoscopy-associated acute massive airway hemorrhage. Trial registration Chinese Clinical Trial Registry on 13/03/2022. Registration number: ChiCTR2200057470.