title: Liposome Bupivacaine Femoral Nerve Block for Postsurgical Analgesia after Total Knee Arthroplasty.
abstract: BACKGROUND
  The authors evaluated the efficacy of liposome bupivacaine in a femoral nerve block (FNB) after total knee arthroplasty.
  
  
  METHODS
  Part 1: subjects received FNB with 20 ml liposome bupivacaine (67, 133, or 266 mg) or placebo. Part 2: subjects were randomized to FNB with liposome bupivacaine 266 mg or placebo. The primary outcome measure was area under the curve of the numeric rating scale score for pain intensity at rest through 72 h (AUC NRS-R0-72) with imputed scores after rescue medication.
  
  
  RESULTS
  In part 1, FNB with liposome bupivacaine 266 mg (n = 24) resulted in analgesia similar to that obtained with 133 mg and was chosen for part 2. In part 2, least-squares mean (standard error) AUC NRS-R0-72 was lower with liposome bupivacaine 266 mg (n = 92) than with placebo (n = 91; 419 [17] vs. 516 [17]; P < 0.0001). This outcome remained unchanged in a post hoc analysis without score imputation (221 [12] vs. 282 [12]; P = 0.0005). Least-squares mean AUC NRS-R with imputed scores was lower with liposome bupivacaine during each 24-h interval (0 to 24, 24 to 48, and 48 to 72 h) after surgery; AUC NRS-R without imputed scores was lower during the 0- to 24-h and 24- to 48-h intervals. The liposome bupivacaine group had lower mean total opioid use (76 vs. 103 mg morphine; P = 0.0016). Pain was sufficiently severe to require second-step rescue with opioids via intravenously administered patient-controlled analgesia in 92% of liposome bupivacaine patients and 81% of placebo patients. With patient-controlled analgesia and other forms of rescue analgesia, mean NRS scores with activity were moderate in both liposome bupivacaine and placebo groups throughout the part 2 study period. Incidence of adverse events was similar between the groups (part 1: 90 vs. 96%; part 2: 96 vs. 96%, respectively).
  
  
  CONCLUSIONS
  FNB with liposome bupivacaine (266 mg) resulted in modestly lower pain scores and reduced opioid requirements after surgery, with an adverse event profile similar to placebo.
authors.affiliation: From the Departments of Anesthesiology, St. Luke's and Roosevelt Hospitals, New York, New York, and Ziekenhouse Oost Limburgh, Genk, Belgium, and the New York School of Regional Anesthesia (NYSORA), New York, New York (A.H.); Department of Anesthesiology, Memorial Hermann Memorial City Medical Center, Houston, Texas (H.S.M.); Department of Anesthesiology, Sheffield Anesthesia, Helen Keller Memorial Hospital, Sheffield, Alabama (T.I.M.); Department of Joint Replacement Surgery, University Hospital, Tamarac, Florida (R.B.); Department of Anesthesiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania (A.U.); Veritas Research, LLC, Mobile, Alabama (F.R.); Pacira Pharmaceuticals, Inc., Parsippany, New Jersey (J.L.); and Department of Anesthesiology, University of California, San Diego, San Diego, California (B.M.I.).
authors.forename: Admir
authors.initials: A
authors.lastname: Hadzic
authors.forename: Harold S
authors.initials: HS
authors.lastname: Minkowitz
authors.forename: Timothy I
authors.initials: TI
authors.lastname: Melson
authors.forename: Richard
authors.initials: R
authors.lastname: Berkowitz
authors.forename: Anna
authors.initials: A
authors.lastname: Uskova
authors.forename: Forrest
authors.initials: F
authors.lastname: Ringold
authors.forename: Janice
authors.initials: J
authors.lastname: Lookabaugh
authors.forename: Brian M
authors.initials: BM
authors.lastname: Ilfeld
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000698:Analgesia / Q000379:methods*; D000779:Anesthetics, Local; D019645:Arthroplasty, Replacement, Knee; D002045:Bupivacaine; D004311:Double-Blind Method; D005260:Female; D005267:Femoral Nerve / Q000187:drug effects; D006801:Humans; D008081:Liposomes; D008297:Male; D008875:Middle Aged; D009407:Nerve Block / Q000379:methods*; D010149:Postoperative Pain / Q000517:prevention & control*; D016896:Treatment Outcome
chemical_list: D000779:Anesthetics, Local; D008081:Liposomes; D002045:Bupivacaine