Feasibility of continuous bronchoscopy during exercise in the assessment of large airway movement in healthy subjects

Excessive dynamic airway collapse (EDAC) is a cause of exertional dyspnoea arising due to invagination of the trachea and/ or main bronchi. Currently, EDAC is assessed by evaluating large airway movement with forced expiratory manoeuvres at rest. We aimed to evaluate large airway behaviour with continuous bronchoscopy during exercise (CBE), in healthy participants, and compared findings with resting bronchoscopic manoeuvres and magnetic resonance imaging (MRI). 28 healthy participants completed two visits including treadmill CBE to voluntary exhaustion, and MRI assessment with forced expiratory manoeuvres at rest. 25 participants (aged 31±9 years, 52% female) completed the study. The majority (76%) achieved a peak heart rate of >90% predicted during CBE. The procedure was prematurely terminated in five participants (n=3; blood pressure >225mmHg, n=2; minor oxygen desaturation [median drop 8% from baseline]). No serious adverse events were reported. No EDAC (tracheal collapse ≥50%) was detected in participants during CBE but was identified in 16 (64%) on MRI, and in 6 (24%) during resting bronchoscopy (Figure 1). The CBE procedure permits visualisation of large airway movement. In healthy participants, there was no evidence of EDAC during vigorous exercise, despite evidence during forced manoeuvres on MRI and bronchoscopic assessments, thus challenging conventional approaches to diagnosis. <fig><object-id>erj;64/suppl_68/OA1961/F1</object-id><object-id>F1</object-id><object-id>F1</object-id><graphic></graphic></fig>