1. Department of Anesthesiology, Guizhou Provincial People's Hospital, Guiyang, Guizhou 550002, P.R. China
2. Department of Anesthesiology, Jinan Zhangqiu District Hospital of TCM, Jinan, Shandong 250200, P.R. China
3. Department of Anesthesiology, Xiamen Hospital of Traditional Chinese Medicine, Xiamen, Fujian 361001, P.R. China