Williams ZJ; Department of Respiratory Medicine, Royal Brompton Hospital, London, UK.
Cenerini G; Orton CM; Garner JL; Chan LT; Tana A; Shah PL; Hull JH;
Journal of applied physiology (Bethesda, Md. : 1985) [J Appl Physiol (1985)] 2025 Nov 17.
Date of Electronic Publication: 2025 Nov 17.
Introduction: Continuous bronchoscopy during exercise (CBE) allows assessment of large airway dynamics during ambulatory exercise, however, it is not yet clear if the bronchoscope alters cardiopulmonary and ventilatory parameters. Accordingly, we aimed to evaluate the impact of bronchoscopy on parameters measured during cardiopulmonary exercise testing (CPET).
Methods: Ten healthy participants (33% female) completed two randomised CPETs to exhaustion on a treadmill using an incremental protocol, with and without bronchoscopy set-up (5.0mm bronchoscope inserted via modified facemask). Breath-by-breath gas exchange and ventilatory data including oxygen uptake (V̇O 2 ) and carbon dioxide output (V̇CO 2 ), minute ventilation (V̇ E ), and respiratory exchange ratio (RER) were assessed between CPET conditions.
Findings: Nine participants completed both CPET assessments to volitional exhaustion; one participant terminated the CPET-B test early due to scope-associated throat discomfort. Exercise duration was shorter (mean diff -52seconds, p=0.02) and heart rate (HR) values were lower (-7BPM, p=0.001) in CPET-B compared to CPET. Peak exercise V̇ E (median diff. -13L.min⁻¹, p=0.004) was lower during CPET-B, yet breathing frequency and tidal volume values did not differ between CPET conditions. No differences were found in peak exercise V̇O 2 , V̇CO 2 , RER values, nor parameters measured at an equivalent absolute duration (iso-time).
Conclusion: In healthy adults, performing CPET with bronchoscopy does not alter peak exercise oxygen uptake or carbon dioxide output but results in a lower overall minute ventilation, despite no differences in breathing frequency or tidal volume. It is likely these discrepancies arise due to slightly lower exercise duration in the CPET with bronchoscopy trials.