Application of high-flow nasal oxygen during anesthesia induction for frame-based stereoelectroencephalography: a randomized controlled non-inferiority trial.

BACKGROUND: High-flow nasal oxygen (HFNO) is increasingly used for preoxygenation and apneic oxygenation; however, its efficacy during anesthesia induction for frame-based stereoelectroencephalography (SEEG) remains uncertain. This study evaluated whether HFNO is non-inferior to facemask ventilation in maintaining oxygenation during anesthesia induction for frame-based SEEG. METHODS: In this randomized, controlled, non-inferiority trial, adult patients with refractory epilepsy undergoing frame-based SEEG were randomized to either the HFNO or facemask group. The primary endpoint was the lowest peripheral oxygen saturation (SpO2). Secondary endpoints included arterial blood gas analyses, hemodynamic measures, airway adjuncts use, first-pass intubation success (FPS), time to secure the airway, anesthesiologist satisfaction, patient comfort, and perioperative complications. RESULTS: Among 46 patients, the median (interquartile range [IQR]) lowest SpO2 was 98 (97-99) % in the HFNO group vs. 96 (95-98) % in the facemask group, with a median difference of 1% (95 confidence interval [CI], 0-2%), confirming non-inferiority within a 2% margin. Post-intubation partial pressure of oxygen (PaO2) was significantly higher in the HFNO group than that in the facemask group, with median (IQR) of 437.8 (411.1-474.4) mmHg and 400.6 (365.6-435.2) mmHg, respectively. HFNO reduced the airway adjuncts use (0/23 vs. 6/23 patients; p = 0.022), shortened the time to secure the airway (p = 0.015), and improved anesthesiologist satisfaction and patient comfort (both p < 0.0001). Hemodynamic parameters and FPS were similar between groups. CONCLUSION: HFNO is non-inferior to facemask ventilation in maintaining oxygenation during anesthesia induction for frame-based SEEG. Moreover, HFNO reduces the need for airway adjuncts, shortens airway securement time, and enhances both patient and anesthesiologist satisfaction. TRIAL REGISTRATION: This study was registered in the Chinese Clinical Trial Registry (ChiCTR2100044239; first registration date: March 12, 2021; https://www.chictr.org.cn/showproj.html?proj=119780 ).