1. Department of Anesthesiology and Pain Medicine, and Anesthesia and Pain Research Institute, Yonsei University College of Medicine, Seoul, Korea.
2. Department of Anesthesiology and Pain Medicine, Kwandong University College of Medicine, Goyang, Korea.
3. Department of Plastic and Reconstructive Surgery, Institute for Human Tissue Restoration, Yonsei University College of Medicine, Seoul, Korea.