The aim of the present study is to measure the time to correction of O2 saturation when in case of desaturation below 90%, O2 administration is switched from the nasal to the tracheal route at a similar flow rate.

The development of a flexible bronchoscope with a channel dedicated to O2 administration might allow optimization of the oxygen supplementation during bronchoscopy, which reduces the risk of per- and peri-procedural hypoxemia. The investigators will conduct a pilot study corroborating the hypothesis that tracheal supplementation of oxygen during flexible bronchoscopy is advantageous in comparison to nasal cannula supplementation.

The concept of our trial consists of a mono-centric observational study performed in the endoscopy suite of the Respiratory Division, University Hospitals Leuven. All patients will be given informed consent before inclusion.

The aim of the present study is to measure the time to correction of O2 saturation when in case of desaturation below 90%, O2 administration is switched from the nasal to the tracheal route at a similar flow rate.

Inclusion Criteria:

• patients referred for flexible bronchoscopy

Exclusion Criteria:

• broncho-alveolar lavage
• endobronchial plugging

all patients referred for flexible bronchoscopy