title: Evaluating therapeutic benefit in postsurgical analgesia requires global assessment: an example from liposome bupivacaine in hemorrhoidectomy.
abstract: OBJECTIVE
  Interpreting analgesic efficacy based solely on measures of pain intensity can be misleading. Here, we use data from an adult hemorrhoidectomy study to demonstrate the importance of evaluating pain intensity scores with other outcome measures in interpreting analgesic study results.
  
  
  METHODS
  We looked for coordinated outcome measures including pain intensity at rest using a numeric rating scale (NRS), postsurgical consumption of rescue medication, subject-reported results from the Brief Pain Inventory, subject satisfaction with postsurgical analgesia, and adverse events.
  
  
  RESULTS
  The analgesic efficacy of liposome bupivacaine was reflected in a significant reduction in pain intensity scores at each timed assessment during the first 12 to 24 hours after surgery (mean NRS at 12 hours: liposome bupivacaine, 2.2; placebo, 2.9; P = 0.04), and less consumption of opioid rescue medications thereafter through 72 hours postsurgery (mean total amount of opioids consumed: liposome bupivacaine, 10 mg; placebo, 18 mg; P = 0.0006). These observations are supported by results of other outcome measures, including time to first use of opioid rescue medication, pain-related interference of subject functionality, and subject satisfaction with postsurgical analgesia.
  
  
  CONCLUSIONS
  Liposome bupivacaine produced superior analgesia when compared with placebo at early postoperative time points, but appropriate use of rescue medication diminished this effect after 12 hours. However, based on our assessment of multiple outcome measures used in the study, it appears that the therapeutic benefit associated with the tested analgesic lasted throughout the 72-hour study period.
authors.affiliation: President, NorthStar Consulting, LLC, Davis, CA 95616, USA. schmidtwk@sbcglobal.net
authors.forename: William K
authors.initials: WK
authors.lastname: Schmidt
authors.forename: Gary
authors.initials: G
authors.lastname: Patou
authors.forename: Girish P
authors.initials: GP
authors.lastname: Joshi
mesh_terms: D000701:Analgesics, Opioid / Q000008:administration & dosage; D000779:Anesthetics, Local / Q000008:administration & dosage / Q000627:therapeutic use*; D002045:Bupivacaine / Q000008:administration & dosage / Q000627:therapeutic use*; D006484:Hemorrhoids / Q000601:surgery*; D006801:Humans; D008081:Liposomes; D017063:Outcome Assessment, Health Care; D059408:Pain Management / Q000379:methods*; D010147:Pain Measurement; D010149:Postoperative Pain / Q000188:drug therapy*; D017060:Patient Satisfaction; D016032:Randomized Controlled Trials as Topic
chemical_list: D000701:Analgesics, Opioid; D000779:Anesthetics, Local; D008081:Liposomes; D002045:Bupivacaine