- The level of postoperative analgesia was evaluated by VAS score, divided into 4 levels, VAS = 0: no pain, VAS = 1 - 3: mild pain, VAS = 4 - 6: moderate pain, VAS = 7 - 10: severe pain - The level of intraoperative sedation was evaluated by OAA / S score, OAA / S = 5 score: alert; OAA / S = 4: light sleep; OAA / S = 3: moderate sleep; OAA / S = 2: deep sleep; OAA / S = 1: very deep sleep, unconscious.