1. Department of Critical Medicine, The Fourth Central Hospital of Baoding City, Baoding, Hebei 072350, P.R. China
2. Department of Otorhinolaryngology, The Fourth Central Hospital of Baoding City, Baoding, Hebei 072350, P.R. China
3. Department of Clinical Laboratory, The Fourth Central Hospital of Baoding City, Baoding, Hebei 072350, P.R. China