Background <p>Patients with obstructive sleep apnea (OSA) are at increased risks of rapid oxygen desaturation during anesthesia, highlighting the need for effective strategies to extend safe apnea time. This study aims to evaluate the efficacy of combining a nasopharyngeal airway (NPA) with transnasal humidified rapid-insufflation ventilator exchange (THRIVE) at 60L/min, compared to THRIVE alone, in prolonging the safe apnea duration and enhancing carbon dioxide elimination in apneic OSA patients.</p> Methods <p>This single-center, prospective, double-blind, randomized controlled trial will include 56 adult patients with OSA scheduled for elective surgery under general anesthesia. Participants will be randomized in a 1:1 ratio to receive either NPA + THRIVE or THRIVE alone. Both groups will undergo standard anesthesia induction, including pre-oxygenation via face mask with 100% FiO₂at 10 L/min. During apnea, patients in both groups will receive oxygen via Optiflow THRIVE at 60 L/min. The primary outcome is the time from the initiation of nasal oxygenation to a peripheral oxygen saturation (SpO₂) of 95%. Secondary outcomes include the lowest SpO₂ during intubation, plateau end-tidal CO₂ (EtCO₂) values, rate of increase of transcutaneous CO₂ (tcCO₂), and time to regain baseline SpO₂ after resuming ventilation.</p> Discussion <p>This trial is expected to provide insights into the effectiveness of combining THRIVE with NPA in prolonging safe apnea time and improving carbon dioxide elimination in OSA patients during anesthesia induction. Positive findings could support adoption THRIVE + NPA as a standard practice in managing OSA patients, potentially lowering perioperative risks associated with hypoxia and hypercapnia.</p> Trial registration <p>This trial was registered on Clinical Trials.gov(NCT 06581588) on Sep 3, 2024.</p>