Corresponding author: Jin-Kyoung Kim, M.D., Ph.D., Department of Anesthesiology and Pain Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50, Ilwon-dong, Gangnam-gu, Seoul 135-710, Korea. Tel: 82-2-3410-2477, Fax: 82-2-3410-6626, E-mail: [email protected] This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial L...