1. Department of Anesthesiology and Pain Medicine, School of Medicine, The Catholic University of Daegu, Daegu, Korea.
2. Department of Anesthesiology and Pain Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
3. Department of Anesthesiology and Pain Medicine, School of Dentistry, Kyungpook National University, Daegu, Korea.
4. Department of Anesthesiology and Pain Medicine, Konkuk University School of Medicine, Seoul, Korea.
5. Department of Anesthesiology and Pain Medicine, College of Medicine, Dong-A University, Busan, Korea.
6. Department of Anesthesiology and Pain Medicine, College of Medicine, Chungnam National University, Daejeon, Korea.
7. Department of Anesthesiology and Pain Medicine, School of Medicine, Keimyung University, Daegu, Korea.