title: Improving Analgesic Efficacy and Safety of Thoracic Paravertebral Block for Breast Surgery: A Mixed-Effects Meta-Analysis.
abstract: BACKGROUND
  While most trials of thoracic paravertebral nerve blocks (TPVB) for breast surgery show benefit, their effect on postoperative pain intensity, opioid consumption, and prevention of chronic postsurgical pain varies substantially across studies. Variability may result from use of different drugs and techniques.
  
  
  OBJECTIVE
  To examine the use of TPVB in breast surgery, and to determine which method(s) provide optimal efficacy and safety.
  
  
  METHODS
  Mixed-Effects Meta-Analysis.
  
  
  METHODS
  We conducted a systematic review of randomized trials comparing TPVB to no intervention using random-effects models. To evaluate the contributions of various techniques, clinical approaches were included as moderators in mixed-effects models.
  
  
  RESULTS
  A total of 24 randomized controlled trials (RCTs) with 1,822 patients were included. Use of TPVB decreased postoperative pain scores at rest and movement at the first 2, 24, 48, and 72 hours. TPVB modestly decreased intraoperative and postoperative opioid consumption, reduced nausea and vomiting, and shortened hospitalization, but to a probably clinically irrelevant degree. Blocks also appeared to reduce the incidence of chronic postsurgical pain at 6 months. Adding fentanyl to the TPVB improved pain at rest (at 24, 48, and 72 hours) and movement (at 24 and 72 hours). Multilevel blocks provided better postoperative pain control, but only during movement (at 2, 48, and 72 hours). Fewer procedural complications (especially hypotension, epidural spread, and Horner's syndrome) occurred when anatomical landmarks were supplemented with ultrasound guidance.
  
  
  CONCLUSIONS
  The number of studies available was limited in the meta-analytic model of incidence of chronic post-surgical pain.
  
  
  CONCLUSIONS
  TPVB reduces postoperative pain and opioid consumption, and has a limited beneficial effect on the quality of recovery. From all the techniques that were evaluated, only the addition of fentanyl, and performing multilevel blocks were associated with improved acute analgesia. TPVB may reduce chronic postsurgical pain at 6 months.
authors.forename: Abdullah S
authors.initials: AS
authors.lastname: Terkawi
authors.affiliation: Department of Epidemiology, Columbia University, New York, NY.
authors.forename: Siny
authors.initials: S
authors.lastname: Tsang
authors.forename: Daniel I
authors.initials: DI
authors.lastname: Sessler
authors.affiliation: Department of Anesthesiology, King Fahad medical city, Riyadh, Saudi Arabia.
authors.forename: Rayan S
authors.initials: RS
authors.lastname: Terkawi
authors.affiliation: Claude Moore Health Sciences Library, University of Virginia, Charlottesville, VA.
authors.forename: Megan S
authors.initials: MS
authors.lastname: Nunemaker
authors.forename: Marcel E
authors.initials: ME
authors.lastname: Durieux
authors.affiliation: Department of Anesthesiology, University of Virginia, Charlottesville, VA.
authors.forename: Ashley
authors.initials: A
authors.lastname: Shilling
mesh_terms: D000700:Analgesics / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology*; D001940:Breast / Q000601:surgery*; D006801:Humans; D008408:Mastectomy / Q000009:adverse effects*; D009407:Nerve Block / Q000009:adverse effects / Q000379:methods* / Q000592:standards; D010149:Postoperative Pain / Q000188:drug therapy*; D016032:Randomized Controlled Trials as Topic
chemical_list: D000700:Analgesics