1. Department of Anesthesia, Xuzhou Cancer Hospital, Xuzhou City, Jiangsu Province, China
2. Department of Anesthesia, Xuzhou Maternity and Child Health Care Hospital, Xuzhou City, Jiangsu Province, China
3. Department of Anesthesia, The People's Hospital of Jiawang District of Xuzhou, Xuzhou City, Jiangsu Province, China
4. Intensive Care Unit, Xuzhou No. 1 People's Hospital, College Road, Xuzhou City, Jiangsu Province, China