title: Discharge Readiness after Tricompartment Knee Arthroplasty: Adductor Canal versus Femoral Continuous Nerve Blocks-A Dual-center, Randomized Trial.
abstract: BACKGROUND
  The authors conducted a randomized, controlled, parallel-arm, superiority study to test the hypothesis that a continuous adductor canal block decreases the time to attain four discharge criteria compared with a continuous femoral nerve block after tricompartment knee arthroplasty.
  
  
  METHODS
  Subjects undergoing tricompartment knee arthroplasty were randomized using computer-generated lists to either an adductor canal or femoral perineural catheter (3-day ropivacaine 0.2% infusion) in an unmasked manner. The primary outcome was the time to attain four criteria: (1) adequate analgesia; (2) intravenous opioids independence; (3) ability to stand, walk 3 m, return, and sit down; and (4) ambulate 30 m.
  
  
  RESULTS
  Subjects with an adductor canal catheter (n = 39) reached all four criteria in a median of 55 h (interquartile, 42 to 63 h) compared with 61 h (49 to 69 h) for those with a femoral catheter (n = 41; 95% CI, -13 to 1 h; P = 0.12). The percentage of subjects who reached the two mobilization criteria on postoperative days 1 and 2 were 72 and 95% for those with an adductor canal catheter (n = 39), but only 27 and 76% in subjects with a femoral catheter (n = 41; both P < 0.001). Differences in pain scores at rest and intravenous opioid requirements were minimal, but femoral infusion improved dynamic analgesia (P = 0.01 to 0.02).
  
  
  CONCLUSIONS
  Compared with a continuous femoral nerve block, a continuous adductor canal block did not appreciably decrease the time to overall discharge readiness even though it did decrease the time until adequate mobilization, primarily because both groups experienced similar analgesia and intravenous opioid requirements that--in most cases--exceeded the time to mobilization.
authors.affiliation: From the Department of Anesthesiology (A.T.M., J.F.S., N.J.K., S.J.M., W.B.A., A.M.M., B.K., B.M.I.) and Department of Orthopaedic Surgery (S.T.B., F.B.G.), School of Medicine (K.A.N.), University of California San Diego, San Diego, California; and Department of Outcomes Research (D.I.S., E.J.M., J.Y.) and Department of Quantitative Health Sciences (E.J.M., J.Y.), the Outcomes Research Consortium (D.I.S., E.J.M., J.Y., B.M.I.), the Cleveland Clinic, Cleveland, Ohio.
authors.forename: Anthony T
authors.initials: AT
authors.lastname: Machi
authors.forename: Jacklynn F
authors.initials: JF
authors.lastname: Sztain
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Kormylo
authors.forename: Sarah J
authors.initials: SJ
authors.lastname: Madison
authors.forename: Wendy B
authors.initials: WB
authors.lastname: Abramson
authors.forename: Amanda M
authors.initials: AM
authors.lastname: Monahan
authors.forename: Bahareh
authors.initials: B
authors.lastname: Khatibi
authors.forename: Scott T
authors.initials: ST
authors.lastname: Ball
authors.forename: Francis B
authors.initials: FB
authors.lastname: Gonzales
authors.forename: Daniel I
authors.initials: DI
authors.lastname: Sessler
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Mascha
authors.forename: Jing
authors.initials: J
authors.lastname: You
authors.forename: Ken A
authors.initials: KA
authors.lastname: Nakanote
authors.forename: Brian M
authors.initials: BM
authors.lastname: Ilfeld
mesh_terms: D000368:Aged; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects* / Q000639:trends*; D001340:Autonomic Nerve Block / Q000379:methods*; D002404:Catheterization / Q000379:methods; D002408:Catheters, Indwelling; D005260:Female; D005267:Femoral Nerve / Q000000981:diagnostic imaging* / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement / Q000379:methods; D010149:Postoperative Pain / Q000000981:diagnostic imaging / Q000517:prevention & control; D010351:Patient Discharge / Q000639:trends*; D014463:Ultrasonography