title: Transversus abdominis plane block reduces morphine consumption in the early postoperative period following microsurgical abdominal tissue breast reconstruction: a double-blind, placebo-controlled, randomized trial.
abstract: BACKGROUND
  The analgesic efficacy of the transversus abdominis plane peripheral nerve block following abdominal tissue breast reconstruction has not been studied in a randomized controlled trial.
  
  
  METHODS
  The authors conducted a double-blind, placebo-controlled, 1:1 allocation, two-arm parallel group, superiority design, randomized controlled trial in patients undergoing microsurgical abdominally based breast reconstruction. Intraoperatively, epidural catheters were inserted under direct vision through the triangle of Petit on both sides of the abdomen into the transversus abdominis plane just before rectus fascial closure. Patients received either bupivacaine (study group) or saline (placebo group) through the catheters for 2 postoperative days. All patients received hydromorphone by means of a patient-controlled analgesic pump. The primary outcome was the difference in the parenteral opioid consumption on each postoperative day between the groups. The secondary outcome measures included the following: total in-hospital opioid; antinausea medication; pain, nausea, and sedation scores; Quality of Recovery Score; time to ambulation; and hospital stay duration.
  
  
  RESULTS
  Between September of 2011 and June of 2013, 93 patients were enrolled: 49 received bupivacaine and 44 received saline. There were 11 postoperative complications (13 percent); none were related to the catheter. Primary outcomes were completed by 85 of 93 patients (91.3 percent); the mean parenteral morphine consumption was significantly reduced on postoperative day 1 in the bupivacaine group (20.7±20.1 mg) compared with 30.0±19.1 mg in the control group (p=0.02). There were no significant differences in secondary outcomes.
  
  
  CONCLUSIONS
  Following abdominally based breast reconstruction, transversus abdominis plane peripheral nerve block is safe and significantly reduces morphine consumption in the early postoperative period.
  
  
  METHODS
  Therapeutic, II.
authors.affiliation: Toronto, Ontario, Canada From the Divisions of Plastic and Reconstructive Surgery and Anesthesia and Pain Management, and the Adult Acute Pain Service, University Health Network; and the Division of Plastic and Reconstructive Surgery, University of Toronto.
authors.forename: Toni
authors.initials: T
authors.lastname: Zhong
authors.forename: M
authors.initials: M
authors.lastname: Ojha
authors.forename: Shaghayegh
authors.initials: S
authors.lastname: Bagher
authors.forename: Kate
authors.initials: K
authors.lastname: Butler
authors.forename: Coimbatore
authors.initials: C
authors.lastname: Srinivas
authors.forename: Stuart A
authors.initials: SA
authors.lastname: McCluskey
authors.forename: Hance
authors.initials: H
authors.lastname: Clarke
authors.forename: Anne C
authors.initials: AC
authors.lastname: O'Neill
authors.forename: Christine B
authors.initials: CB
authors.lastname: Novak
authors.forename: Stefan O P
authors.initials: SOP
authors.lastname: Hofer
mesh_terms: D000009:Abdominal Muscles / Q000187:drug effects* / Q000294:innervation; D000273:Adipose Tissue / Q000601:surgery / Q000637:transplantation*; D000328:Adult; D016058:Analgesia, Patient-Controlled; D001943:Breast Neoplasms / Q000473:pathology / Q000601:surgery; D002045:Bupivacaine / Q000008:administration & dosage; D016009:Chi-Square Distribution; D004311:Double-Blind Method; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007430:Intraoperative Care / Q000379:methods; D053208:Kaplan-Meier Estimate; D016462:Mammaplasty / Q000379:methods*; D008408:Mastectomy / Q000379:methods; D008866:Microsurgery / Q000379:methods; D008875:Middle Aged; D009020:Morphine / Q000008:administration & dosage*; D009407:Nerve Block / Q000379:methods*; D009864:Ontario; D010147:Pain Measurement; D010149:Postoperative Pain / Q000188:drug therapy / Q000517:prevention & control*; D018570:Risk Assessment; D016896:Treatment Outcome
chemical_list: D009020:Morphine; D002045:Bupivacaine