Postintubation tracheal stenosis is a complication of endotracheal intubation. The pathological mechanism and risk factors for endotracheal intubation-induced tracheal stenosis remain not fully understood. We aimed to establish an animal model and to investigate risk factors for postintubation tracheal stenosis. Beagles were intubated with 4 sized tubes (internal diameter 6.5 to 8.0 mm) and cuff pressures of 100 to 200 mmHg for 24 hr. The status of tracheal wall was evaluated by bronchoscopic and histological examinations. The model was successfully established by cuffed endotracheal intubation using an 8.0 mm tube and an intra-cuff pressure of 200 mmHg for 24 hr. When the intra-cuff pressures were kept constant, a larger sized tube would induce a larger tracheal wall pressure and more severe injury to the tracheal wall. The degree of tracheal stenosis ranged from 78% to 91% at 2 weeks postextubation. Histological examination demonstrated submucosal infiltration of inflammatory cells, hyperplasia of granulation tissue and collapse of tracheal cartilage. In summary, a novel animal model of tracheal stenosis was established by cuffed endotracheal intubation, whose histopathological feathers are similar to those of clinical cases of postintubation tracheal stenosis. Excessive cuff pressure and over-sized tube are the risk factors for postintubation tracheal stenosis.

Background: Patients with pulmonary tuberculosis (PTB) have a high risk of concomitant tracheobronchial tuberculosis (TBTB), which commonly causes severe complications such as tracheobronchial stenosis. The prevalence and predictors of TBTB in China remain unclear due to the lack of prospective and large-scale studies. Objectives: To investigate the incidence of TBTB in PTB patients in southern China, and elucidate the predictors of TBTB and related tracheobronchial stenosis. Methods: We prospectively performed bronchoscopy in PTB patients to diagnose TBTB at four medical centres in southern China from September 2015 to August 2016. Clinical and epidemiological data were recorded and analysed to determine predictors of TBTB and related tracheobronchial stenosis. Results: A total of 345 (23.9%) of the 1,442 PTB patients undergoing bronchoscopy were diagnosed with TBTB. Female sex (OR 2.53), age < 50 years (OR 1.88), living in urban (OR 2.19), diabetes (OR 1.84), coughing (OR 2.61), and symptoms ≥4 weeks (OR 1.66) were predictors of PTB concomitant with TBTB. About 59.7% TBTB patients developed tracheobronchial stenosis, of which 23.3% cases presented severe airway narrowing. Female sex (OR 2.27), age < 50 years (OR 2.11), shortness of breath (OR 1.97), and symptoms ≥4 weeks (OR 1.71) were predictors of TBTB-related tracheobronchial stenosis. Conclusions: About 23.9% of PTB patients undergoing bronchoscopy present with TBTB in Guangdong province, southern China. Young and middle-aged females with symptoms persisting for ≥4 weeks (the main predictors of TBTB and related tracheobronchial stenosis) should receive bronchoscopy immediately when diagnosed with PTB.

BackgroundThe benefits of noninvasive positive pressure ventilation (NPPV) in patients with hypercapnic COPD are controversial. It is presumed that methodology and appropriate use of NIV ventilator might be crucial for the outcomes. With the new built-in software, the performance of NIV can be monitored at home, which can guarantee the compliance and appropriate use. This study investigated effects of home use of NIV in hypercapnia in COPD patients using the NIV ventilator with built-in software for monitoring.MethodsThe current multicenter prospective, randomized, controlled trial enrolled patients with stable GOLD stages III and IV hypercapnic COPD. Patients were randomly assigned via a computer-generated randomization sequence, with a block size of four patients, to continue optimized treatment (control group) or to receive additional NPPV (intervention group) for 3 months. The primary outcome was arterial carbon dioxide pressure (PaCO2). Data were derived from built-in software and analyzed every 4 weeks. Analysis was carried out with the intention to treat. This study is registered with ClinicalTrials.gov, number NCT02499718.ResultsPatients were recruited from 20 respiratory units in China from October 1, 2015, and recruitment was terminated with a record of the vital statistics on May 31, 2016. A total of 115 patients were randomly assigned to the NPPV group (n=57) or the control group (n=58). Patients complied well with NPPV therapy (mean [± standard deviation] day use 5.6±1.4 h). The mean estimation of leaks was 37.99±13.71 L/min. The changes in PaCO2 (−10.41±0.97 vs −4.32±0.68 mmHg, P=0.03) and 6-min walk distance (6MWD) (38.2% vs 18.2%, P=0.02) were statistically significant in the NPPV group versus the control group. COPD assessment test (CAT) showed a positive trend (P=0.06) in favor of the NPPV group. Pulmonary function and dyspnea were not different between groups.ConclusionVentilators equipped with built-in software provided methodology for monitoring NIV use at home, which could facilitate the improvement of compliance and quality control of NIV use. It was shown that three months use of NIV at home could reduce the PaCO2 and improve exercise tolerance (6MWD) in chronic hypercapnic COPD patients.