1. Emergency Department, China-Japan Friendship Hospital, Beijing 100029, China
2. Graduate School of Peking Union Medical College, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing 100193, China
3. Department of Respiratory and Critical Care Medicine, China-Japan Friendship Hospital, Beijing 100029, China
4. Surgical Intensive Care Unit (SICU), China-Japan Friendship Hospital, Beijing 100029, China
5. Department of Digestive, Beijing Ditan Hospital Capital Medical University, Beijing 100015, China
6. Department of Emergency, Peking University People's Hospital (PKUPH), Beijing 100044, China