Hangzhou, China

Author Affiliations: Department of Anesthesiology, Children’s Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China (Hu YQ, Wang DP, Kang J and Shu Q)

Corresponding Author: Yao-Qin Hu, MD, Department of Anesthesiology, Children’s Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China (Tel: 86-571-87061007 ext 60317; Fax: 86-571-87078641; Email: huyaoqin@sina.com)