1. Department of Anesthesiology and Pain Medicine, Chungnam National University Hospital, Daejeon, Korea
2. Department of Anesthesiology and Pain Medicine, College of Medicine, Chungnam National University, Daejeon, Korea
3. Department of Orthopedic Surgery, Chungnam National University Hospital and College of Medicine, Daejeon, Korea
4. College of Nursing, Chungnam National University, Daejeon, Republic of Korea