Background Hypoxia elicits ventilatory adaptation, and the anterior insula, a hub for interoceptive and exteroceptive integration, is highly vulnerable to hypoxic stress. We hypothesised that it mediates hypoxia-related ventilatory regulation.Methods Thirty-one college students completed 30 days of high altitude exposure. Respiratory function tests and multimodal MRI were conducted immediately at high altitude. Moreover, follow-up MRI scans were performed 7 days, 2 months, and 3 months after the students returned to sea level.Results Pulmonary function (peak expiratory flow (PEF), forced vital capacity (FVC), forced expiratory volume in one second (FEV1), FEV1/FVC%, maximal mid-expiratory flow (MMF) and minute ventilation (MV)) significantly declined after high altitude exposure. The ALFF increased in the insular cortex, with enhanced FC with the thalamus, motor cortex and postcentral cortex. FC of the left anterior insula with the thalamus was negatively correlated with FEV1 predicted values, while right lateral prefrontal insula-thalamus connectivity was positively correlated with FEV1 and MMF. FC of the anterior insula with the motor cortex and postcentral cortex was negatively correlated with PEF%, FVC and FEV1, respectively. Moreover, fibre pathways linking the anterior insular cortex with the thalamus, motor cortex and postcentral cortex showed increased fibre numbers between these brain regions. Follow-up MRI studies showed that ALFF in the anterior insular cortex was significantly increased immediately after reoxygenation and then recovered to baseline level.Conclusion The anterior insula may serve as a potential hub for integrating hypoxic signals from the thalamus and modulating motor cortex activity, which may contribute to hypoxic ventilation.
Background Quantitative computed tomography (QCT) has emerged as a promising tool for chronic obstructive pulmonary disease (COPD) phenotyping. However, its prognostic value in acute exacerbations of COPD (AECOPD) remains insufficiently explored, and existing risk stratification models have limited integration of imaging-derived metrics. This study aimed to develop and validate a prognostic model that integrates multidimensional clinical variables with QCT-derived metrics, and to compare its predictive performance with traditional clinical scores for in-hospital mortality in AECOPD.Methods In this retrospective cohort study, consecutive patients aged ≥40 years hospitalized with severe AECOPD were enrolled from September 2010 to October 2024, with collection of demographic characteristics, clinical features, laboratory indices, and chest CT imaging data. The cohort was randomly split into training and testing sets (7:3). Candidate predictors were selected using least absolute shrinkage and selection operator (LASSO) regression followed by multivariable logistic regression. Four classification models were developed and evaluated using 10-fold cross-validation. Discriminative performance was assessed by area under the receiver operating characteristic curve (AUC) and compared with conventional clinical scores.Results A total of 465 patients with AECOPD were included, of whom 47 (10.1%) died during hospitalization. Five independent predictors were identified: confusion, lymphocyte count <0.8 × 109/L, chronic heart failure, white blood cell count ≥10 × 109/L, and reduced pulmonary vascular fractal dimension. The logistic regression model demonstrated the best performance, achieving an AUC of 0.852 (95% CI, 0.738–0.965) in the testing set, significantly outperforming other models and established clinical scores.Conclusions A predictive model integrating QCT-derived metrics with clinical features improved AECOPD in-hospital mortality prediction over traditional scores, supporting its utility for individualized risk stratification and management.
Background No instruments exist to assess palliative care knowledge among Portuguese with chronic respiratory diseases. Aim To translate and cross-culturally adapt the Palliative Care Knowledge Scale (PaCKS) into European Portuguese and explore its measurement properties in chronic obstructive pulmonary disease (COPD) and interstitial lung diseases (ILD). Methods Translation and cross-cultural adaptation procedures were followed. Internal consistency (Cronbach's alpha); test-retest reliability [intraclass correlation coefficient with 95% confidence interval (ICC2,1 [95% CI]), standard error of measurement (SEM/SEM%), minimal detectable change at 95% confidence level (MDC95/MDC%) and Bland-Altman method]; floor/ceiling effects; and, construct validity [convergent/divergent, correlation (Spearman's -r(s)) with the Bristol COPD Knowledge Questionnaire (BCKQ)/modified Medical Research Council dyspnoea questionnaire/lung function] were evaluated. Results Two forward translations/back-translations were conducted. Five experts approved the prefinal version. Cognitive debriefing involved 12 participants. Measurement properties were analysed in 102 people with COPD and 54 with ILD (73.1% male; 67.6 +/- 10.0 years). PaCKS score was 11.0 [9.0-12.0] and 10.0 [8.8-11.0] in COPD and ILD, respectively. Internal consistency was acceptable (alpha(COPD) = 0.76; alpha(ILD) = 0.80). The test-retest reliability was good in COPD (ICC2,1 0.84 [0.77-0.89]) and ranged from good to excellent in ILD (ICC2,1 0.89 [0.78-0.94]). SEM/SEM% and MDC95/MDC% were 1.0/9.6% and 2.8/26.6%, and 1.0/10.1% and 2.7/28.0% in COPD and ILD, respectively. The Bland-Altman method did not suggest systematic bias, with 95% limits of agreement of approximately +/- 3.0. No floor/ceiling effects were observed, except for a ceiling effect in COPD (20.6%). The PaCKS/BCKQ correlation was significant, positive and moderate (r(s) = 0.40, p < 0.001) in COPD. Other correlations were non-significant and ranged from negligible to weak. Conclusion The European Portuguese PaCKS is now available and provides reliable and valid data on palliative care knowledge in COPD and ILD
Background Prior to the onset of overt ventilatory failure, patients with Duchenne Muscular Dystrophy (DMD) can display non-uniform respiratory mechanics, resulting from atelectasis in small lung regions secondary to rapid, shallow breathing and/or peripheral airway obstruction, thereby predisposing to the development of ventilation inhomogeneity. Objectives To investigate ventilation distribution in DMD patients before the initiation of long-term assisted ventilation by using electrical impedance tomography (EIT). Methods Patients and interventions: Eighteen DMD patients underwent EIT between 1 January and 31 December 2025. Primary study endpoint: Global Inhomogeneity Index (GI). EIT data were compared with those obtained from a group of 11 healthy, similarly aged male medical residents. Results GI was significantly higher in the DMD patients with respect to healthy males [0.44 +/- 0.13 (0.36-0.77) vs 0.37 +/- 0.03 (0.32-0.43); p < 0.001]. A GI of 0.5 maximised the distinction between DMD patients with a ventilation distribution pattern similar to or different from the healthy subjects. Conclusions Before initiation of assisted ventilation, a subset of DMD patients may develop lung ventilation inhomogeneity, which can be readily assessed by means of EIT. Whether such inhomogeneity is predictive of major clinical events therefore constitutes a critical question to be addressed.
