Sung Il Bae1, Ju-Tae Sohn. 1. Department of Anesthesiology and Pain Medicine, Gyeongsang National University Hospital, Jinju-si, Republic of Korea Department of Anesthesiology and Pain Medicine, Gyeongsang National University, College of Medicine, Gyeongsang National University Hospital, Institute of Health Sciences, Gyeonsang National University, Jinju-si, Republic of Korea jtsohn@gnu.ac.kr.