1. Department of Anesthesiology and Pain Medicine, Anesthesia and Pain Research Institute, Yonsei University College of Medicine, Gangnam Severance Hospital, Seoul, Republic of Korea
2. Department of Anesthesiology and Pain Medicine, Anesthesia and Pain Research Institute, Yonsei University College of Medicine, Seoul, Republic of Korea
3. Division of Colon and Rectal Surgery, Department of Surgery, Yonsei University College of Medicine, Seoul, Republic of Korea
4. Department of Anesthesiology and Pain Medicine, Yonsei University College of Medicine, Gangnam Severance Hospital, Seoul, Republic of Korea