The effect of high-flow nasal cannula oxygen therapy on preventing hypoxemia during deep sedation extubation after laparoscopic surgery: a prospective randomized controlled trial

BACKGROUND: High-flow nasal cannula (HFNC) oxygen therapy has shown potential benefits in improving oxygenation in perioperative settings. However, its role in preventing early postoperative hypoxemia after extubation under deep sedation during laparoscopic surgery remains unclear. METHODS: This single-center randomized controlled trial enrolled 120 patients undergoing elective laparoscopic surgery. After extubation under deep sedation, patients were randomized to receive either HFNC or NC until discharge from the post-anesthesia care unit (PACU). Extubation under deep sedation was performed during emergence after discontinuation of anesthetic agents, when patients had regained spontaneous respiration but had not yet fully recovered consciousness, according to predefined clinical and bispectral index criteria.The primary outcome was hypoxemia, defined as peripheral oxygen saturation (SpO₂) < 90% for > 60 s between extubation and PACU discharge. Secondary outcomes included arterial partial pressure of oxygen/inspired oxygen fraction (PaO₂/FiO₂), arterial partial pressure of carbon dioxide (PaCO₂), heart rate, mean arterial pressure, and perioperative complications. Parameters were measured at six time points: before anesthesia (T0), immediately after extubation (T1), and at 5 (T2), 15 (T3), 30 (T4) minutes post-extubation, and at PACU discharge (T5). RESULTS: Hypoxemia occurred in 24/60 (40%) NC patients and 12/60 (20%) HFNC patients (P = 0.028). Of those, mask-assisted positive pressure ventilation was needed in 11/24 NC and 2/12 HFNC patients (P = 0.026); jaw thrust was performed in 13/24 and 10/12, respectively. At T2 and T3, PaO₂/FiO₂ was higher (T2: 333.0 ± 34.6 vs. 286.3 ± 41.7; T3: 345.9 ± 34.5 vs. 303.2 ± 40.3 mmHg; both P < 0.001) and PaCO₂ lower (T2: 42.2 ± 4.2 vs. 48.8 ± 3.8; T3: 39.6 ± 3.7 vs. 45.3 ± 3.6 mmHg; both P < 0.001) in the HFNC group. No differences were found in PACU stay or other complications. CONCLUSIONS: HFNC oxygen therapy after extubation under deep sedation significantly reduces hypoxemia and improves early respiratory function versus NC, with comparable safety. TRIAL REGISTRATION: Chinese Clinical Trial Registry (ChiCTR2500107249, August 7, 2025).