title: Effects of two different anesthesia-analgesia methods on incidence of postoperative delirium in elderly patients undergoing major thoracic and abdominal surgery: study rationale and protocol for a multicenter randomized controlled trial.
abstract: BACKGROUND
  Delirium is a common complication in elderly patients after surgery and associated with increased morbidity and mortality. Studies suggest that deep anesthesia and intense pain are important precipitating factors of postoperative delirium. Neuraxial block is frequently used in combination with general anesthesia for patients undergoing major thoracic and abdominal surgery. Compared with general anesthesia alone and postoperative intravenous analgesia, combined epidural-general anesthesia and postoperative epidural analgesia decreases the requirement of general anesthetics during surgery and provided better pain relief after surgery. However, whether combined epidural-general anesthesia plus epidural analgesia is superior to general anesthesia plus intravenous analgesia in decreasing the incidence of postoperative delirium remains unknown.
  
  
  METHODS
  This is a multicenter, open-label, randomized, parallel-controlled clinical trial. One thousand eight hundred elderly patients (age range 60-90 years) who are scheduled to undergo major thoracic or abdominal surgery are randomized to receive either general anesthesia plus postoperative intravenous analgesia or combined epidural-general anesthesia plus postoperative epidural analgesia. The primary outcome is the 7-day incidence of postoperative delirium. Secondary outcomes include the duration of postoperative delirium, the intensity of pain during the first three days after surgery, the 30-day incidences of postoperative non-delirium complications, the length of stay in hospital after surgery and 30-day all-cause mortality.
  
  
  CONCLUSIONS
  Results of the present study will provide information to guide clinical practice in choosing appropriate anesthesia-analgesia method for elderly patients undergoing major thoracic and abdominal surgery.
  
  
  BACKGROUND
  The study is registered on ClinicalTrials.gov NCT01661907 and Chinese Clinical Trial Registry ChiCTR-TRC-12002371 .
authors.affiliation: Department of Anesthesiology and Critical Care Medicine, Peking University First Hospital, No.8 Xishiku Street, Xicheng District, Beijing, 100034, China.
authors.forename: Ya-Wei
authors.initials: YW
authors.lastname: Li
authors.affiliation: Peking University Clinical Research Institute, No.38 Xueyuan Road, Haidian District, Beijing, 100191, China.
authors.forename: Hui-Juan
authors.initials: HJ
authors.lastname: Li
authors.affiliation: Department of Anesthesiology and Critical Care Medicine, Peking University First Hospital, No.8 Xishiku Street, Xicheng District, Beijing, 100034, China.
authors.forename: Huai-Jin
authors.initials: HJ
authors.lastname: Li
authors.affiliation: Department of Anesthesiology, Peking University People's Hospital, No.11 Xizhimen South Street, Xicheng District, Beijing, 100044, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Feng
authors.affiliation: Department of Anesthesiology, Peking University People's Hospital, No.11 Xizhimen South Street, Xicheng District, Beijing, 100044, China.
authors.forename: Yao
authors.initials: Y
authors.lastname: Yu
authors.affiliation: Department of Anesthesiology, Peking University Third Hospital, No.49 Huayuan North Road, Haidian District, Beijing, 100191, China.
authors.forename: Xiang-Yang
authors.initials: XY
authors.lastname: Guo
authors.affiliation: Department of Anesthesiology, Peking University Third Hospital, No.49 Huayuan North Road, Haidian District, Beijing, 100191, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Anesthesiology, Beijing Shijitan Hospital, No.10 Tieyi Road, Haidian District, Beijing, 100038, China.
authors.forename: Bin-Jiang
authors.initials: BJ
authors.lastname: Zhao
authors.affiliation: Department of Anesthesiology, Beijing Shijitan Hospital, No.10 Tieyi Road, Haidian District, Beijing, 100038, China.
authors.forename: Xiao-Yun
authors.initials: XY
authors.lastname: Hu
authors.affiliation: Department of Anesthesiology, Beijing Hospital, No.1 Dahua Road, Dongcheng District, Beijing, 100730, China.
authors.forename: Ming-Zhang
authors.initials: MZ
authors.lastname: Zuo
authors.affiliation: Department of Anesthesiology, Beijing Hospital, No.1 Dahua Road, Dongcheng District, Beijing, 100730, China.
authors.forename: Hong-Ye
authors.initials: HY
authors.lastname: Zhang
authors.affiliation: Peking University Clinical Research Institute, No.38 Xueyuan Road, Haidian District, Beijing, 100191, China.
authors.forename: Mei-Rong
authors.initials: MR
authors.lastname: Wang
authors.affiliation: Peking University Clinical Research Institute, No.38 Xueyuan Road, Haidian District, Beijing, 100191, China.
authors.forename: Ping
authors.initials: P
authors.lastname: Ji
authors.affiliation: Peking University Clinical Research Institute, No.38 Xueyuan Road, Haidian District, Beijing, 100191, China.
authors.forename: Xiao-Yan
authors.initials: XY
authors.lastname: Yan
authors.affiliation: Peking University Clinical Research Institute, No.38 Xueyuan Road, Haidian District, Beijing, 100191, China.
authors.forename: Yang-Feng
authors.initials: YF
authors.lastname: Wu
authors.affiliation: Department of Anesthesiology and Critical Care Medicine, Peking University First Hospital, No.8 Xishiku Street, Xicheng District, Beijing, 100034, China. wangdongxin@hotmail.com.
authors.forename: Dong-Xin
authors.initials: DX
authors.lastname: Wang
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015360:Analgesia, Epidural / Q000379:methods*; D000767:Anesthesia, Epidural / Q000379:methods*; D000768:Anesthesia, General / Q000379:methods*; D000771:Anesthesia, Intravenous / Q000379:methods*; D003693:Delirium / Q000175:diagnosis / Q000453:epidemiology / Q000517:prevention & control*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D010149:Postoperative Pain / Q000175:diagnosis / Q000517:prevention & control; D011183:Postoperative Complications / Q000175:diagnosis / Q000453:epidemiology / Q000517:prevention & control; D019616:Thoracic Surgical Procedures / Q000009:adverse effects*; D016896:Treatment Outcome