title: Preoperative versus postoperative ultrasound-guided rectus sheath block for improving pain, sleep quality and cytokine levels of patients with open midline incisions undergoing transabdominal gynaecological operation: study protocol for a randomised controlled trial.
abstract: BACKGROUND
  Rectus sheath block (RSB) is used for postoperative pain relief in patients undergoing abdominal surgery with midline incision. Preoperative RSB has been shown to be effective, but it has not been compared with postoperative RSB. The aim of the present study is to evaluate postoperative pain, sleep quality and changes in the cytokine levels of patients undergoing gynaecological surgery with RSB performed preoperatively versus postoperatively.
  
  
  METHODS
  This study is a prospective, randomised, controlled (randomised, parallel group, concealed allocation), single-blinded trial. All patients undergoing transabdominal gynaecological surgery will be randomised 1:1 to the treatment intervention with general anaesthesia as an adjunct to preoperative or postoperative RSB. The objective of the trial is to evaluate postoperative pain, sleep quality and changes in the cytokine levels of patients undergoing gynaecological surgery with RSB performed preoperatively (n = 32) versus postoperatively (n = 32). All of the patients, irrespective of group allocation, will receive patient-controlled intravenous analgesia (PCIA) with oxycodone. The primary objective is to compare the interval between leaving the post-anaesthesia care unit and receiving the first PCIA bolus injection on the first postoperative night between patients who receive preoperative versus postoperative RSB. The secondary objectives will be to compare (1) cumulative oxycodone consumption at 24 hours after surgery; (2) postoperative sleep quality, as measured using a BIS-Vista monitor during the first night after surgery; and (3) cytokine levels (interleukin-1, interleukin-6, tumour necrosis factor-α and interferon-γ) during surgery and at 24 and 48 hours postoperatively.
  
  
  CONCLUSIONS
  Clinical experience has suggested that RSB is a very effective postoperative analgesic technique, and we will answer the following questions with this trial. Do preoperative block and postoperative block have the same duration of analgesic effects? Can postoperative block extend the analgesic time? The results of this study could have actual clinical applications that could help to reduce postoperative pain and shorten hospital stays.
  
  
  BACKGROUND
  Current Controlled Trials NCT02477098 15 June 2015.
authors.affiliation: Department of Anaesthesiology, the First Hospital of China Medical University, Shenyang, China. pp0807@163.com.
authors.forename: Feng
authors.initials: F
authors.lastname: Jin
authors.affiliation: Department of Anaesthesiology, the First Hospital of China Medical University, Shenyang, China. shirley037305@hotmail.com.
authors.forename: Xiao-Qian
authors.initials: XQ
authors.lastname: Li
authors.affiliation: Department of Anaesthesiology, the First Hospital of China Medical University, Shenyang, China. winfieldtan@hotmail.com.
authors.forename: Wen-Fei
authors.initials: WF
authors.lastname: Tan
authors.affiliation: Department of Anaesthesiology, the First Hospital of China Medical University, Shenyang, China. mahong5466@yahoo.com.
authors.forename: Hong
authors.initials: H
authors.lastname: Ma
authors.affiliation: Department of Anaesthesiology, the First Hospital of China Medical University, Shenyang, China. hwl1998@yahoo.com.
authors.forename: Huang-Wei
authors.initials: HW
authors.lastname: Lu
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000577:Amides / Q000008:administration & dosage* / Q000009:adverse effects; D016058:Analgesia, Patient-Controlled / Q000379:methods; D000701:Analgesics, Opioid / Q000008:administration & dosage; D000779:Anesthetics, Local / Q000008:administration & dosage* / Q000009:adverse effects; D002681:China; D002985:Clinical Protocols; D056805:Consciousness Monitors; D016207:Cytokines / Q000097:blood*; D004334:Drug Administration Schedule; D005260:Female; D013509:Gynecologic Surgical Procedures / Q000009:adverse effects* / Q000379:methods; D006801:Humans; D008875:Middle Aged; D009407:Nerve Block / Q000009:adverse effects / Q000379:methods*; D010098:Oxycodone / Q000008:administration & dosage; D010147:Pain Measurement; D017288:Pain Threshold / Q000187:drug effects; D010149:Postoperative Pain / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control*; D011446:Prospective Studies; D017568:Rectus Abdominis / Q000000981:diagnostic imaging / Q000294:innervation / Q000601:surgery*; D012107:Research Design; D000077212:Ropivacaine; D016037:Single-Blind Method; D012890:Sleep / Q000187:drug effects*; D013997:Time Factors; D016896:Treatment Outcome; D018084:Ultrasonography, Interventional; D055815:Young Adult
chemical_list: D000577:Amides; D000701:Analgesics, Opioid; D000779:Anesthetics, Local; D016207:Cytokines; D000077212:Ropivacaine; D010098:Oxycodone