Ventilatory Effects of THRIVE During EBUS

High flow nasal cannula (HFNC) is used in interventional procedures to prevent hypoxia during sedation. In patients with a patent airway, HFNC reduces dead space ventilation as well. It is unknown if dead space ventilation is also reduced by HFNC in an EndoBroncheal UltraSound procedure, in which the airway is partially blocked by the endoscope. Especially in patients with Chronic Obstructive Pulmonary Disease (COPD) the partial blocking of the airway may reduce ventilation. If HFNC is able to reduce dead space during an EBUS-procedure, it may facilitate CO2 clearance, which may lead to a reduction in work of breathing. This study aims to investigate if HFNC reduces dead space ventilation in patients undergoing an EBUS-procedure and if this is flow-dependent. A randomized, double-blinded, cross-over study is designed.