1. Department of Critical Care Medicine, Provincial Hospital Affiliated to Shandong University, Jinan 250021, China
2. Department of Emergency, Zaozhuang Municipal Hospital, Zaozhuang, Shandong 277101, China
3. Department of Critical Care Medicine, Beijing Tiantan Hospital, Capital Medical University, Beijing 100050, China
4. Department of Internal Medicine, Rongcheng Traditional Hospital, Weihai 264300, China