Pu Shen, Li Xiao, Tao Zhang, Department of Anesthesia, the First Affiliated Hospital, Sun Yat-sen University, Guangzhou 510080, Guangdong Province, China
Kai-Jun Huang, Chuan-Zhao Zhang, Department of General Surgery, Guangdong Provincial People’s Hospital, Guangdong Academy of Medical Sciences, Guangzhou 510080, Guangdong Province, China
Author contributions: Shen P and Zhang T designed and organized the study protocol; Huang KJ and Xiao L reviewed and selected the papers; Shen P and Zhang CZ extracted and analyzed the data and wrote the paper; all authors had access to the data and statistical analyses, approved the final article, and attested to the validity of the results.
Supported by the Medical Scientific Research Foundation of Guangdong Province, No. A2017229.
Conflict-of-interest statement: The authors disclose no potential conflicts of interest.
PRISMA 2009 Checklist statement: The authors have read the PRISMA 2009 Checklist, and the manuscript was prepared and revised according to the PRISMA 2009 Checklist.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Corresponding author: Tao Zhang, MD, Doctor, Professor, Department of Anesthesia, the First Affiliated Hospital, Sun Yat-sen University, No. 58, Zhongshan II Road, Guangzhou 510080, Guangdong Province, China. email@example.com
Telephone: +86-20-37583761 Fax: +86-20-37583761
Received: April 13, 2019
Peer-review started: April 15, 2019
First decision: May 16, 2019
Revised: June 4, 2019
Accepted: June 10, 2019
Article in press: June 10, 2019
Published online: June 30, 2019