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

Abstract

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).

Keywords: bronchoscopy; high-flow nasal cannula; hypoxemia; oxygen therapy.