Affiliation: | 1. Department of Orthopedics, Peking Union Medical College Hospital, Beijing, PR China;2. Department of anesthesiology, Peking Union Medical College Hospital, Beijing, PR China;1. Department of Anesthesiology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan, Republic of China;2. Department of Anesthesia, Kaohsiung Municipal Ta-Tung Hospital, Kaohsiung, Taiwan, Republic of China |