1. Department of Emergency Surgery, The Affiliated Hospital of Qingdao University, 16 Jiangsu Road, Qingdao 266000, China
2. Department of General Surgery, The Affiliated Hospital of Qingdao University, 16 Jiangsu Road, Qingdao 266000, China
3. Department of Critical Care Medicine, The Affiliated Hospital of Qingdao University, 16 Jiangsu Road, Qingdao 266000, China