Study interventions
Patients who met the eligible criteria were then randomized into two groups by a
computer-generated randomized sequence with a block size of four. Sequentially numbered sealed opaque envelopes were provided to the independent investigators
Patients in the nasal irrigation group received a mixture of 250 mL of normal saline solution and 10% fluorescein sodium 10 mL, irrigated 125 mL each nostril, using a syringe of 20 mL (contain a volume of 25 mL) (Terumo, Tokyo, Japan) with a nozzle, 30 minutes before entering the operating room. Patients in the nasal spray group received a mixture of corticosteroid suspension and 10% fluorescein sodium 10 mL, utilizing a single-use mometasone nasal spray bottle (Sandoz, Ljubljana, Slovenia), with 2 puffs sprayed into each nostril 30 minutes before entering the operating room. The trained in-charge nurses supervised and instructed all the patients to bend their heads forward, 30-45 degrees, to the vertical plane during irrigation and spray. After receiving the interventions, the patients were asked to sit upright until they could lay down in the operating room, preparing for anesthesia.