The pain degree at rest or coughing was assessed with visual analog scale (VAS) before surgery and at 4, 12, 24 and 48 hours after surgery respectively: 0 as painless, 10 as extremely painful.

• 在术前、术后4,12,24和48h采用目测类比评分法(VAS)对患者休息和咳嗽时的疼痛程度进行评分,0分为无痛,10为极痛。