title: Author's Reply.
authors.affiliation: Department of Critical Care Medicine, The First Affiliated Hospital of Dalian Medical University, Dalian, China. Electronic address: liqingdong2@163.com.
authors.forename: Qingdong
authors.initials: Q
authors.lastname: Li
mesh_terms: D003422:Critical Care / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D010147:Pain Measurement / Q000379:methods*; D012121:Respiration, Artificial