title: Prospective randomized observer-blinded study comparing the analgesic efficacy of ultrasound-guided rectus sheath block and local anaesthetic infiltration for umbilical hernia repair.
abstract: BACKGROUND
  Umbilical hernia repair, a common day-surgery procedure in children, is associated with considerable postoperative discomfort. Possible modes of postoperative analgesia for umbilical hernia repair are rectus sheath block (RSB) and local anaesthetic infiltration of the surgical site (LAI).
  
  
  METHODS
  We undertook an observer-blinded, randomized, prospective, observational study to compare the efficacy of ultrasound-guided RSB and LAI in providing postoperative analgesia for umbilical hernia repair. Our primary objective was to compare the use of opioid medication between patients who receive RSB and those who receive LAI. Our secondary objectives were to compare the duration of analgesia based on time to first rescue analgesic, to compare the quality of analgesia based on revised FACES scale, and to determine the incidence of side-effects.
  
  
  RESULTS
  Fifty-two patients (26 in each group) completed the study. There was a statistically significant difference in the perioperative opioid medication consumption between the LAI group [mean: 0.13 mg kg(-1), confidence interval (0.09-0.17 mg kg⁻¹)] and the RSB group [mean: 0.07 mg kg⁻¹, confidence interval (0.05-0.09 mg kg⁻¹)] (P=0.008). When we compared the postoperative opioid consumption between the LAI group [mean: 0.1 mg kg⁻¹, 95% confidence interval (0.07-0.13 mg kg⁻¹)] and the RSB group [mean: 0.07 mg kg(-1), 95% confidence interval (0.05-0.09 mg kg⁻¹)] (P=0.09), there was a trend towards statistical significance between the two groups. The difference in time to rescue analgesic administration between the RSB group [49.7 (36.9) min] and the LAI group [32.4 (29.4) min] was not statistically significant (P=0.11).
  
  
  CONCLUSIONS
  This study demonstrates that ultrasound-guided RSB provides superior analgesia in the perioperative period compared with infiltration of the surgical site after umbilical hernia repair. In comparing only the postoperative period, analgesia provided by an ultrasound-guided RSB showed a trend towards statistically significant improvement compared with infiltration of the surgical site.
authors.affiliation: Department of Anesthesiology and Critical Care Medicine, The Children's Hospital of Philadelphia and University of Pennsylvania School of Medicine, Philadelphia, PA 19104-4399, USA. gurnaney@email.chop.edu
authors.forename: H G
authors.initials: HG
authors.lastname: Gurnaney
authors.forename: L G
authors.initials: LG
authors.lastname: Maxwell
authors.forename: F W
authors.initials: FW
authors.lastname: Kraemer
authors.forename: T
authors.initials: T
authors.lastname: Goebel
authors.forename: M L
authors.initials: ML
authors.lastname: Nance
authors.forename: A
authors.initials: A
authors.lastname: Ganesh
mesh_terms: D000293:Adolescent; D000698:Analgesia; D000701:Analgesics, Opioid; D000779:Anesthetics, Local; D002045:Bupivacaine; D002648:Child; D002675:Child, Preschool; D004311:Double-Blind Method; D005260:Female; D006554:Hernia, Umbilical / Q000601:surgery*; D006801:Humans; D008297:Male; D009020:Morphine; D009407:Nerve Block / Q000379:methods*; D010098:Oxycodone; D010147:Pain Measurement; D010149:Postoperative Pain / Q000188:drug therapy*; D011446:Prospective Studies; D017568:Rectus Abdominis / Q000000981:diagnostic imaging; D016896:Treatment Outcome; D018084:Ultrasonography, Interventional / Q000379:methods*
chemical_list: D000701:Analgesics, Opioid; D000779:Anesthetics, Local; D009020:Morphine; D010098:Oxycodone; D002045:Bupivacaine