Viedo-assisted thoracoscopic surgery(VATS) have became popular in recent years. There is no golden rule of postoperative analgesia for VATS. Compared with lobectomy, wedge resection preserves better pulmonary function and is suitable for elder patients and patients who could not afford to have lobectomy. In addition to surgery time、recovery time and hospital stay, wound incisions and organization damages are different,too. Will patients also have different response to pain control after these two surgery? The retrospective study is to compared the differences of postoperative pain management between VATS lobectomy and wedge resection.

Inclusion Criteria:

1. Age >= 20
2. Using intravenous patient-controlled analgesia for postoperative analgesia
3. ASA physical status classification I-III

Exclusion Criteria:

1. Staying in intensive care unit after surgery
2. Emergency surgery
3. Pregnancy
4. Other surgery incisions which are not used for the video-assisted thoracoscopic surgery
5. Patients never use intravenous patient-controlled analgesia after surgery

Selected patients are from the hospital patients who are arranged to have video-assisted thoracoscopic surgery for lobectomy or wedge resection