Assessment of High Flow Nasal Cannula Oxygenation in Endobronchial Ultrasound Bronchoscopy

BACKGROUND: Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) has been widely implemented in evaluating mediastinal disease. EBUS-TBNA is performed with low flow oxygen systems or general anesthesia. Little data exist on use of high flow nasal cannula (HFNC) in EBUS-TBNA. METHODS: This was a single center parallel group randomized controlled trial comparing oxygenation through HFNC (Optiflow) against nasal prongs during EBUS. The primary end-point was the drop in oxygen saturations from procedure commencement, recorded by pulse oximetry, to the lowest level during EBUS-TBNA. Secondary end-points included changes in venous blood carbon dioxide, lowest oxygen saturation, changes in end-tidal CO2 during the procedure, intubation within 8 hours of the procedure and patient experience reported on a visual analog scale. RESULTS: We randomized 20 patients to each study arm. The primary outcome of oxygen desaturation during the procedure was statistically significant with a difference of 7.7 percentage points (95% confidence interval, 4.91-10.49, P<0.001). The secondary outcome measure of lowest oxygen saturation was also statistically significant with a difference of -9.2 (95% confidence interval, -11.96 to -6.44, P<0.001). There was no difference in safety outcomes, visual analog scale score or in their willingness to return for repeat procedure. CONCLUSION: This single institution study in a university, tertiary referral center confirms that EBUS-TBNA performed with HFNC is associated with a statistically significant lower drop in oxygen saturation. Additional studies are needed to assess if this translates into improved clinical outcomes postprocedure.