1 Department of Anesthesiology, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan Second Road, Yuexiu District, Guangzhou, Guangdong, 510080, P.R. China.
2 The Second School of Clinical Medicine, Southern Medical University, Guangzhou, China.
3 Department of Anesthesiology, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan Second Road, Yuexiu District, Guangzhou, Guangdong, 510080, P.R. China. shuhaihua@hotmail.com.
4 The Second School of Clinical Medicine, Southern Medical University, Guangzhou, China. shuhaihua@hotmail.com.