1 Department of Anaesthesiology and Pain Medicine, Daejeon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Daejeon, South Korea; Department of Anaesthesiology and Pain Medicine, College of Medicine, The Catholic University of Korea, Seoul, South Korea.
2 Department of Anaesthesiology and Pain Medicine, Daejeon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Daejeon, South Korea; Department of Anaesthesiology and Pain Medicine, College of Medicine, The Catholic University of Korea, Seoul, South Korea. Electronic address: seungukb@naver.com.
3 Department of Orthopaedic surgery, Daejeon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Daejeon, South Korea; Department of Orthopaedic Surgery, College of Medicine, The Catholic University of Korea, Seoul, South Korea.