title: A multicenter, randomized, triple-masked, placebo-controlled trial of the effect of ambulatory continuous femoral nerve blocks on discharge-readiness following total knee arthroplasty in patients on general orthopaedic wards.
abstract: A continuous femoral nerve block (cFNB) involves the percutaneous insertion of a catheter adjacent to the femoral nerve, followed by a local anesthetic infusion, improving analgesia following total knee arthroplasty (TKA). Portable infusion pumps allow infusion continuation following hospital discharge, raising the possibility of decreasing hospitalization duration. We therefore used a multicenter, randomized, triple-masked, placebo-controlled study design to test the primary hypothesis that a 4-day ambulatory cFNB decreases the time until each of three predefined readiness-for-discharge criteria (adequate analgesia, independence from intravenous opioids, and ambulation 30m) are met following TKA compared with an overnight inpatient-only cFNB. Preoperatively, all patients received a cFNB with perineural ropivacaine 0.2% from surgery until the following morning, at which time they were randomized to either continue perineural ropivacaine (n=39) or switch to normal saline (n=38). Patients were discharged with their cFNB and portable infusion pump as early as postoperative day 3. Patients who were given 4 days of perineural ropivacaine attained all three criteria in a median (25th-75th percentiles) of 47 (29-69)h, compared with 62 (45-79)h for those of the control group (Estimated ratio=0.80, 95% confidence interval: 0.66-1.00; p=0.028). Compared with controls, patients randomized to ropivacaine met the discharge criterion for analgesia in 20 (0-38) versus 38 (15-64)h (p=0.009), and intravenous opioid independence in 21 (0-37) versus 33 (11-50)h (p=0.061). We conclude that a 4-day ambulatory cFNB decreases the time to reach three important discharge criteria by an estimated 20% following TKA compared with an overnight cFNB, primarily by improving analgesia.
authors.affiliation: Department of Anesthesiology, University of California San Diego, San Diego, CA, USA Department of Orthopaedic Surgery, University of California San Diego, San Diego, CA, USA VA Healthcare System, San Diego, CA, USA Department of Anesthesiology, University of California San Francisco, San Francisco, CA, USA Department of Anesthesiology, Alta Bates Summit Medical Center, Oakland, CA, USA Department of Orthopaedics, Alta Bates Summit Medical Center, Oakland, CA, USA Department of Anesthesiology, University of Florida, Gainesville, FL, USA Department of Outcomes Research, Cleveland Clinic, Cleveland, OH, USA Department of Epidemiology and Health Policy Research, University of Florida, Gainesville, FL, USA General Clinical Research Center, University of Florida, Gainesville, FL, USA.
authors.forename: Brian M
authors.initials: BM
authors.lastname: Ilfeld
authors.forename: Edward R
authors.initials: ER
authors.lastname: Mariano
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Girard
authors.forename: Vanessa J
authors.initials: VJ
authors.lastname: Loland
authors.forename: Scott R
authors.initials: SR
authors.lastname: Meyer
authors.forename: John F
authors.initials: JF
authors.lastname: Donovan
authors.forename: George A
authors.initials: GA
authors.lastname: Pugh
authors.forename: Linda T
authors.initials: LT
authors.lastname: Le
authors.forename: Daniel I
authors.initials: DI
authors.lastname: Sessler
authors.forename: Jonathan J
authors.initials: JJ
authors.lastname: Shuster
authors.forename: Douglas W
authors.initials: DW
authors.lastname: Theriaque
authors.forename: Scott T
authors.initials: ST
authors.lastname: Ball
mesh_terms: D000368:Aged; D000553:Ambulatory Care / Q000379:methods*; D000577:Amides / Q000627:therapeutic use; D000779:Anesthetics, Local / Q000627:therapeutic use; D019645:Arthroplasty, Replacement, Knee / Q000379:methods*; D004311:Double-Blind Method; D005260:Female; D005267:Femoral Nerve / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D008875:Middle Aged; D009020:Morphine / Q000627:therapeutic use; D009407:Nerve Block / Q000379:methods*; D010149:Postoperative Pain / Q000188:drug therapy; D010351:Patient Discharge; D000077212:Ropivacaine; D013997:Time Factors
chemical_list: D000577:Amides; D000779:Anesthetics, Local; D009020:Morphine; D000077212:Ropivacaine