title: Continuous transversus abdominis plane (TAP) blocks for postoperative pain control after hernia surgery: a randomized, triple-masked, placebo-controlled study.
abstract: BACKGROUND
  Single-injection transversus abdominis plane (TAP) block provides postoperative analgesia and decreases supplemental analgesic requirements. However, there is currently no evidence from randomized, controlled studies investigating the possible benefits of continuous TAP blocks. Therefore, the aim of this randomized, triple-masked, placebo-controlled study was to determine if benefits are afforded by adding a multiple-day, ambulatory, continuous ropivacaine TAP block to a single-injection block following hernia surgery.
  
  
  METHODS
  Preoperatively, subjects undergoing unilateral inguinal (N=19) or peri-umbilical (N=1) hernia surgery received unilateral or bilateral TAP perineural catheter(s), respectively. All received a ropivacaine 0.5% (20 mL) bolus via the catheter(s). Subjects were randomized to either postoperative perineural ropivacaine 0.2% or normal saline using portable infusion pump(s). Subjects were discharged home where the catheter(s) were removed the evening of postoperative day (POD) 2. Subjects were contacted on POD 0-3. The primary endpoint was average pain with movement (scale: 0-10) queried on POD 1.
  
  
  RESULTS
  Twenty subjects of a target 30 were enrolled due to the primary surgeon's unanticipated departure from the institution. Average pain queried on POD 1 for subjects receiving ropivacaine (N=10) was a mean (standard deviation) of 3.0 (2.6) vs 2.8 (2.7) for subjects receiving saline (N=10; 95% confidence interval difference in means -2.9 to 3.4; P=0.86). There were no statistically significant differences detected between treatment groups in any secondary endpoint.
  
  
  CONCLUSIONS
  The results of this study do not support adding an ambulatory, continuous ropivacaine infusion to a single-injection ropivacaine TAP block for hernia surgery. However, the present investigation was underpowered, and further study is warranted.
authors.affiliation: Department of Anesthesiology, University of California San Diego, San Diego, California, USA.
authors.forename: Justin W
authors.initials: JW
authors.lastname: Heil
authors.forename: Ken A
authors.initials: KA
authors.lastname: Nakanote
authors.forename: Sarah J
authors.initials: SJ
authors.lastname: Madison
authors.forename: Vanessa J
authors.initials: VJ
authors.lastname: Loland
authors.forename: Edward R
authors.initials: ER
authors.lastname: Mariano
authors.forename: NavParkash S
authors.initials: NS
authors.lastname: Sandhu
authors.forename: Michael L
authors.initials: ML
authors.lastname: Bishop
authors.forename: Rishi R
authors.initials: RR
authors.lastname: Agarwal
authors.forename: James A
authors.initials: JA
authors.lastname: Proudfoot
authors.forename: Eliza J
authors.initials: EJ
authors.lastname: Ferguson
authors.forename: Anya C
authors.initials: AC
authors.lastname: Morgan
authors.forename: Brian M
authors.initials: BM
authors.lastname: Ilfeld
mesh_terms: D000009:Abdominal Muscles / Q000187:drug effects; D000577:Amides / Q000008:administration & dosage; D000779:Anesthetics, Local / Q000008:administration & dosage*; D004311:Double-Blind Method; D005260:Female; D006552:Hernia, Inguinal / Q000601:surgery; D006554:Hernia, Umbilical / Q000601:surgery; D059685:Herniorrhaphy / Q000009:adverse effects*; D006801:Humans; D007260:Infusion Pumps; D008297:Male; D008875:Middle Aged; D009407:Nerve Block / Q000379:methods*; D010149:Postoperative Pain / Q000188:drug therapy*; D000077212:Ropivacaine
chemical_list: D000577:Amides; D000779:Anesthetics, Local; D000077212:Ropivacaine
keywords: Anesthesiology; Postoperative Pain; Regional Pain