Comparison of High-Flow Nasal Cannula and Conventional Oxygen Therapy for High Risk Patients During Bronchoscopy Examination: A Multicenter Randomized Controlled Trial

Rationale: Despite the increasing use of high-flow nasal cannula (HFNC) oxygen therapy during endoscopy examination, its impact on high-risk patients remains uncertain. Objectives: We aimed to compare HFNC and conventional oxygen therapy (COT) during nasal bronchoscopy in patients at high risk for desaturation (morbid obesity, narrow trachea, or baseline hypoxemia and/or hypercapnia). Methods: In this multicenter randomized controlled trial, patients scheduled for bronchoscopy and presenting with any high-risk factors were randomly assigned to receive HFNC or COT after providing written consent. Vital signs, pulse oximetry (Sp_O2), and transcutaneous carbon dioxide were continuously monitored. The occurrence of desaturation (Sp_O2 ⩽ 90% lasted >10 s), frequency of examination interruption, and treatment escalation were compared between groups. Results: Of 148 initially enrolled patients, 6 withdrew, leaving 72 and 70 in the HFNC and COT groups, respectively. Most of the patients had airway stenosis. HFNC significantly reduced desaturation occurrence during bronchoscopy (34.7% vs. 61.4%; P = 0.016), with fewer instances of examination interruption (26.4% vs. 58.6%; P < 0.001) and less frequent treatment escalation (30.6% vs. 57.1%; P = 0.001). During the examination, the lowest Sp_O2 was higher with HFNC (94% [interquartile range, 87-98%] vs. 87.5% [79-93%]; P = 0.001), whereas the highest transcutaneous carbon dioxide was lower (64.6 [56.8-70.1] vs. 68.3 [62.3-77.0] mm Hg; P = 0.04). No significant differences were observed regarding the time to the first desaturation, bronchoscopy withdrawal, durations of desaturation and bronchoscopy examination, or occurrence of other adverse events between groups. Conclusions: In a high-risk population with predominant airway stenosis, HFNC significantly reduced desaturation occurrence, examination interruption, and treatment escalation during nasal bronchoscopy examination in high risk patients. Clinical trial registered with www.chictr.org.cn (ChiCTR2100055038).