Opioid-Sparing Multimodal Analgesia Efficacy in Hispanic Patients Undergoing Total Knee Arthroplasty

Abstract

Background: Adequate pain control after total knee arthroplasty (TKA) has been associated with improved patient mobility and satisfaction, and is a task that has historically relied on opioids. Multimodal analgesic regimens can be considered a therapeutic alternative for postoperative pain control to avoid opioid consumption and its adverse side effects. This study aimed to evaluate the use of a multimodal analgesia protocol based on nonsteroidal anti-inflammatory drugs (NSAIDs) and acetaminophen as an alternative to reduce opioid consumption in Hispanic patients undergoing primary TKA. Methods: An institutional review board-approved, randomized controlled trial evaluated postoperative pain control after TKA in a Hispanic population. The experimental opioid-sparing group received 30-mg ketorolac intravenously every 6 hours and 1-g acetaminophen orally every 6 hours as the patient requested. The experimental group had the option to use morphine and oxycodone combined with acetaminophen as a rescue therapy. The control group received opioids in the form of 0.1-mg/kg morphine intravenously every 6 hours and/or oxycodone combined with acetaminophen (2.5 and 325 mg), 2 tablets orally every 6 hours, as the patient requested. Sociodemographic, operative, and immediate postoperative data and pain intensity measurements according to the numerical rating scale (NRS) were compared between groups. Analgesic efficacy was assessed according to the NRS scores at 12, 24, and 48 hours postoperatively. Results: Eighty-one Hispanic patients met inclusion criteria: 42 patients in the experimental group and 39 patients in the control group. None of the patients in the experimental group requested oxycodone combined with acetaminophen as a rescue therapy. Only 2 patients in the experimental group used a mean of 3.0 ± 1.4 mg of rescue morphine; in comparison, the control group consumed a mean of 28.0 ± 7.9 mg of morphine and 64.8 ± 26.0 mg of oxycodone per patient. A pain intensity decrease was observed in the experimental and control groups, with no postoperative evaluation differences at 12 hours (6.7 ± 2.9 compared with 5.9 ± 2.8; p = 0.209), 24 hours (6.2 ± 2.0 compared with 6.1 ± 2.2; p = 0.813), and 48 hours (4.7 ± 2.1 compared with 4.6 ± 1.7; p = 0.835). Conclusions: The use of a multimodal analgesic regimen based on intravenous ketorolac and oral acetaminophen was adequate in reducing postoperative pain and opioid consumption in Hispanic patients undergoing TKA. Level of Evidence: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.