Abstract: Objective To explore the effect of THRIVE combined with i-gel laryngeal mask on the safety of oxygen therapy in apnea and surgical precision of retrograde intrarenal surgery. Methods A total of 120 patients undergoing retrograde intrarenal surgery under general anesthesia with laryngeal mask were randomized into 3 groups (n=40), and after the flexible ureteroscope entered the renal pelvis and located the stones, the patients received assisted ventilation in APPV mode (control group), ventilation with small tidal volume and high respiratory rate (group H), or THRIVE combined with laryngeal mask for oxygen supply without using the ventilator (THRIVE group). The time for lithotripsy by the surgeons, surgeons' satisfaction, diaphragm mobility, and times of urinary tract mucosal injury were recorded, and arterial blood pressure, heart rate, SpO2, PaO2, PaCO2, and pH value were measured before, during and after lithotripsy. Results Among the 3 groups, THRIVE group had the shortest time for lithotripsy, best satisfaction of the surgeons, the lowest diaphragmatic mobility of the patients, and the smallest number of mucosal injuries. The arterial blood pressure, heart rate, and SpO2 of the patients did not differ significantly among the 3 groups. At 20 min and 30 min after the start of lithotripsy, PaO2 decreased significantly in group H and THRIVE group; in THRIVE group, PaCO2 increased and pH decreased significantly at 10, 20 and 30 min after the start of lithotripsy. No significant difference was found in oxygenation indicators among the 3 groups upon discharge from the PACU. Conclusion In retrograde intrarenal surgery, THRIVE combined with i- gel laryngeal mask for oxygen therapy during the anaerobic period can improve the surgical accuracy and maintain the patient's oxygenation index in a controllable range within 30 min.

Key words: transnasal humidified rapid-insufflation ventilatory exchange; retrograde intrarenal surgery; apneic oxygenation; surgical precision