1 Department of General Surgery, the Affiliated Hospital of Guizhou Medical University, No. 28 Guiyi Street, Yunyan District, 550004, Guiyang, China.
2 Department of Anesthesiology, the Affiliated Hospital of Guizhou Medical University, No. 28 Guiyi Street, Yunyan District, 550004, Guiyang, China. Electronic address: huangyanruo@126.com.