title: The effect of single-injection femoral nerve block on rehabilitation and length of hospital stay after total knee replacement.
abstract: OBJECTIVE
  Continuous-infusion femoral nerve block (FNB) improves analgesia and rehabilitation after total knee replacement. In this study, we investigated the efficacy of single-injection FNB to achieve similar results.
  
  
  METHODS
  A total of 30 patients were prospectively and randomly assigned to receive 40-mL injections of either 0.25% bupivacaine (group B) or saline (group S) after total knee replacement. Blinded observers evaluated the patients for postoperative pain, morphine consumption, ambulating distances, and maximal knee flexion; pain was scored on the visual analog scale (VAS).
  
  
  RESULTS
  Compared with group S patients, group B patients had significantly lower VAS pain scores (P <.01 in the postoperative anesthesia care unit, P <.05 on the day after surgery); group B patients also showed significantly lower total morphine use (P <.05) and a lower incidence of morphine-related side effects. Significantly more group B than group S patients could ambulate on the day after surgery (93% v 46%, P <.05), and mean ambulatory distance was significantly better for group B than group S patients at discharge (166 +/- 37 v 117 +/- 24 feet, P <.01). Knee flexion was significantly better for group B than group S patients on the second day after surgery (70 degrees v 60 degrees, P <.01), but the between-group difference was no longer statistically significant at discharge. Mean length of acute hospitalization was significantly shorter for group B (3 days; range, 3 to 5 days) than group S patients (4 days; range, 3 to 6 days, P <.05).
  
  
  CONCLUSIONS
  Single-injection FNB provided effective analgesia, facilitated early ambulation, and reduced the length of acute hospitalization in patients undergoing total knee replacement.
authors.affiliation: Department of Anesthesiology, Henry Ford Hospital, 2799 W. Grand Boulevard, Detroit, MI 48202, USA. hwang2@hfhs.org
authors.forename: Hong
authors.initials: H
authors.lastname: Wang
authors.forename: Baher
authors.initials: B
authors.lastname: Boctor
authors.forename: James
authors.initials: J
authors.lastname: Verner
mesh_terms: D000328:Adult; D000368:Aged; D019645:Arthroplasty, Replacement, Knee / Q000534:rehabilitation*; D004311:Double-Blind Method; D005260:Female; D005267:Femoral Nerve; D006801:Humans; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D009020:Morphine / Q000627:therapeutic use; D009407:Nerve Block; D010149:Postoperative Pain / Q000517:prevention & control; D011446:Prospective Studies
chemical_list: D009020:Morphine