1. Department of Anesthesiology and Perioperative Medicine, Xijing Hospital, Fourth Military Medical University, Xi'an, China.
2. Department of Anesthesiology, Chinese PLA General Hospital, Beijing, China.
3. Department of Psychiatry, Xijing Hospital, Fourth Military Medical University, Xi'an, China.
4. The Medical Department of the Emergence Center of Xi'an, Xi'an, Shaanxi, China.