This study investigates volatile organic compound (VOC) profiles in the exhaled breath of normal subjects under different oxygenation conditions—normoxia (FiO2 21%), hypoxia (FiO2 11%), and hyperoxia (FiO2 35%)—using an electronic nose (e-nose). We aim to identify significant differences in VOC profiles among the three conditions utilizing principal component analysis (PCA) and canonical discriminant analysis (CDA). Our results indicate distinct VOC patterns corresponding to each oxygenation state, demonstrating the potential of e-nose technology in detecting physiological changes in breath composition (cross-validated accuracy values: FiO2 21% vs. FiO2 11% = 63%, FiO2 11% vs. FiO2 35% = 65%, FiO2 21% vs. FiO2 35% = 71%, and p < 0.05 for all). This research underscores the viability of breathomics in the non-invasive monitoring and diagnostics of various respiratory and systemic conditions.

Background/Objectives: Life-threatening haemoptysis primarily fatal due to airway obstruction, and the culprit vessel must be identified before it can be occluded. Bronchial artery embolisation (BAE) is the established haemostatic treatment, yet its success is largely determined upstream, by the accuracy of the diagnostic chain that precedes it: computed tomography angiography (CTA), bronchoscopy and selective angiography. These modalities are conventionally deployed sequentially and by separate teams. Case Presentation: An 84-year-old male patient presented with abrupt life-threatening haemoptysis. CTA demonstrated an ectatic left bronchial artery with arterial-phase venous opacification, diagnostic of a bronchial arteriovenous fistula (BAVF). Because this phenotype determines both the embolic agent and the definition of technical success, bronchoscopy and angiography were performed concurrently. Endoscopy localised pulsatile bleeding to the left upper lobe bronchus and secured the airway; superselective angiography confirmed the fistula, which was occluded with detachable platinum microcoils under continuous endoscopic observation. Conclusions: Outcome in life-threatening haemoptysis depends less on the embolic device than on whether imaging, endoscopy and angiography operate within a single decision-making environment. We propose a phenotype-driven, dual-endpoint workflow, supported by a structured CTA reading checklist and an embolic-agent selection framework, as a reproducible model for the multidisciplinary management of pulmonary vascular emergencies.