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
Brian M Ilfeld, Edward R Mariano, Paul J Girard, Vanessa J Loland, Scott R Meyer, John F Donovan, George A Pugh, Linda T Le, Daniel I Sessler, Jonathan J Shuster, Douglas W Theriaque, Scott T Ball, Brian M Ilfeld, Edward R Mariano, Paul J Girard, Vanessa J Loland, Scott R Meyer, John F Donovan, George A Pugh, Linda T Le, Daniel I Sessler, Jonathan J Shuster, Douglas W Theriaque, Scott T Ball
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.
Conflict of interest statement
Conflicts of Interest: Teleflex Medical and Stryker Instruments provided funding and donated portable infusion pumps for this investigation, these two companies had absolutely no input into any aspect of study conceptualization, design, and implementation; data collection, analysis and interpretation; or manuscript preparation. The funding from these companies was used by each institution to help defray research coordinator expenses. Drs. Mariano and Loland conduct continuous peripheral nerve block workshops for Stryker Instruments. No other author has a personal financial interest in this research.
Copyright (c) 2010 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.
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Source: PubMed