Perioperative changes of oxygen desaturation index (ODI) (A) and cumulative time percentage with SpO₂ less than 90% (CT90) (B) from oximeter in the auto-titrated continuous positive airway pressure (APAP) and the control group. Data represented as median (middle point) and interquartile range (25th, 75th percentile) *Adjusted P < 0.05 compared with control group at the same night. Postop = postoperative; Preop = preoperative.