1. Department of Anesthesiology and Pain Medicine, Kyungpook National University School of Dentistry, Daegu, Korea.
2. Department of Anesthesiology and Pain Medicine, Kyungpook National University School of Medicine, Daegu, Korea.
3. Department of Anesthesiology and Pain Medicine, Dongguk University Ilsan Hospital, Dongguk University College of Medicine, Goyang, Korea.
4. Department of Anesthesiology and Pain Medicine, Seoul National University Hospital, Seoul, Korea.
5. Center for Liver Cancer, National Cancer Center, Goyang, Korea.