1. Department of Critical Care Medicine, Hainan Medical University, Haikou, Hainan 570311, P.R. China
2. Department of Critical Care Medicine, The Second Affiliated Hospital of Hainan Medical University, Haikou, Hainan 570311, P.R. China
3. Department of Pathophysiology, Hainan Medical University, Haikou, Hainan 570311, P.R. China
4. Department of Neurology, The Second Affiliated Hospital of Hainan Medical University, Haikou, Hainan 570311, P.R. China