1. Department of Anesthesiology, Zoucheng People’s Hospital, Zoucheng, Shandong, China (mainland)
2. Department of Anesthesiology, Jining No. 1 People’s Hospital, Jining Medical University, Jining, Shandong, China (mainland)
3. Department of Anesthesiology, Beijing Friendship Hospital, Capital Medical University, Beijing, China (mainland)