1. Department of Emergency, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450052, P.R. China
2. Department of Gastroenterology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450052, P.R. China
3. Department of General ICU, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450052, P.R. China