A Comparison of Oxygenation Efficacy between High-Flow Nasal Cannulas and Standard Facemasks during Elective Tracheal Intubation for Patients with Obesity: A Randomized Controlled Trial.

Obese patients are predisposed to rapid oxygen desaturation during tracheal intubation. We aimed to compare the risk of desaturation between high-flow nasal oxygenation (HFNO) and classical facemask oxygenation (FMO) during rapid sequence intubation for elective surgery in obese patients. Adults with a body mass index ≥30 kg·m -2 undergoing laparoscopic sleeve gastrectomy at a medical center were randomized into the HFNO group ( n = 40) and FMO group ( n = 40). In the HFNO group, patients used a high-flow nasal cannula to receive 30 to 50 L·min -1 flow of heated and humidified 100% oxygen. In the FMO group, patients received a fitting facemask with 15 L·min -1 flow of 100% oxygen. After 5-min preoxygenation, rapid sequence intubation was performed. The primary outcome was arterial desaturation during intubation, defined as a peripheral capillary oxygen saturation (SpO 2 ) <92%. The risk of peri-intubation desaturation was significantly lower in the HFNO group compared to the FMO group; absolute risk reduction: 0.20 (95% confidence interval: 0.05-0.35, p = 0.0122); number needed to treat: 5. The lowest SpO 2 during intubation was significantly increased by HFNO (median 99%, interquartile range: 97-100) compared to FMO (96, 92-100, p = 0.0150). HFNO achieved a higher partial pressure of arterial oxygen (PaO 2 ) compared to FMO, with medians of 476 mmHg (interquartile range: 390-541) and 397 (351-456, p = 0.0010), respectively. There was no difference in patients' comfort level between groups. Compared with standard FMO, HFNO with apneic oxygenation reduced arterial desaturation during tracheal intubation and enhanced PaO 2 among patients with obesity.