Retraction Note: Oxycodone versus morphine for analgesia after laparoscopic endometriosis resection

Affiliations

• ¹ Department of Anesthesiology, The First Affiliated Hospital, Sun Yat-sen University, No.58, Zhongshan 2nd Road, Guangzhou, 510080, China.
• ² Department of Anesthesiology, The Six Affiliated Hospital, Sun Yat-sen University, No. 26, Erheng Road, Guangzhou, 510655, China.
• ³ Department of Anesthesiology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, No.54 Xianlie South Road, Guangzhou, 510060, China.
• ⁴ Department of Anesthesiology, Nanfang Hospital, Southern Medical University, 1838 Guangzhou Avenue North, Guangzhou, China.
• ⁵ Department of Anesthesiology, The First Affiliated Hospital, Sun Yat-sen University, No.58, Zhongshan 2nd Road, Guangzhou, 510080, China. liysheng@mail.sysu.edu.cn.