title: Reduction of verbal pain scores after anterior cruciate ligament reconstruction with 2-day continuous femoral nerve block: a randomized clinical trial.
abstract: BACKGROUND
  Single-injection femoral nerve block analgesia and spinal anesthesia have been associated with fewer postoperative nursing interventions and successful same-day discharge after anterior cruciate ligament reconstruction. In the current study, the authors prospectively determined the effect of continuous femoral nerve block on a numeric rating scale (NRS) of pain intensity with movement for 7 postoperative days.
  
  
  METHODS
  Patients undergoing this surgery with no history of previous invasive surgery on the same knee were recruited for this study. After standardized spinal anesthesia, intravenous sedation, and perioperative multimodal analgesia, patients received a femoral nerve catheter with (1) saline bolus (30 ml) plus saline infusion (270 ml at 5 ml/h, placebo group); (2) levobupivacaine (0.25%) bolus with saline infusion (group I), or (3) levobupivacaine (0.25%) bolus and infusion (group II). Patients were surveyed preoperatively and on postoperative days 1-4 and 7 to determine NRS scores (scale 0-10).
  
  
  RESULTS
  Data from 233 participants were analyzed. On days 1-2, 50% of placebo patients had NRS scores of 5 or above, whereas among group II patients, only 25% had scores of 5 or above (P < 0.001). In regression models for NRS scores during days 1-4, group II was the only factor predicting lower pain scores (odds ratios, 0.3-0.5; P = 0.001-0.03). Overall, patients with preoperative NRS scores greater than 2 were likely to report higher NRS scores during days 1-7 (odds ratios, 3.3-5.2; P < 0.001).
  
  
  CONCLUSIONS
  Femoral nerve block catheters reliably keep NRS scores below the moderate-to-severe pain threshold for the first 4 days after anterior cruciate ligament reconstruction.
authors.affiliation: Department of Anesthesiology, University of Pittsburgh Medical Center, 2000 Mary Street, Pittsburgh, PA 15203, USA. williamsba@anes.upmc.edu
authors.forename: Brian A
authors.initials: BA
authors.lastname: Williams
authors.forename: Michael L
authors.initials: ML
authors.lastname: Kentor
authors.forename: Molly T
authors.initials: MT
authors.lastname: Vogt
authors.forename: James J
authors.initials: JJ
authors.lastname: Irrgang
authors.forename: Matthew T
authors.initials: MT
authors.lastname: Bottegal
authors.forename: Robin V
authors.initials: RV
authors.lastname: West
authors.forename: Christopher D
authors.initials: CD
authors.lastname: Harner
authors.forename: Freddie H
authors.initials: FH
authors.lastname: Fu
authors.forename: John P
authors.initials: JP
authors.lastname: Williams
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000701:Analgesics, Opioid / Q000627:therapeutic use; D000775:Anesthesia, Spinal; D016118:Anterior Cruciate Ligament / Q000601:surgery*; D005260:Female; D005267:Femoral Nerve; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009068:Movement; D009407:Nerve Block; D019637:Orthopedic Procedures; D010098:Oxycodone / Q000627:therapeutic use; D010147:Pain Measurement / Q000187:drug effects*; D010149:Postoperative Pain / Q000175:diagnosis / Q000188:drug therapy*; D011446:Prospective Studies; D019651:Plastic Surgery Procedures
chemical_list: D000701:Analgesics, Opioid; D010098:Oxycodone