1. Department of Emergency, The First Affiliated Hospital of Hainan Medical University, No. 31, Longhua Road, Longhua District, Haikou City, Hainan Province, 570102, P. R. China
2. School of Medicine, Tongji University, Shanghai 200092, P. R. China
3. Intensive Medical Unit, Hainan General Hospital, Hainan Affiliated Hospital of Hainan Medical University, No. 19 Xiuhua Road, Haikou, China