Efficacy of acetaminophen on preemptive multimodal analgesia in total knee arthroplasty: a prospective, double-blind, randomized placebo-controlled trial

Abstract

Abstract BackgroundPreemptive multimodal analgesia is a commonly used method to control pain following total knee arthroplasty (TKA). This study aimed to evaluate the efficacy of preemptive acetaminophen for pain management in patients who underwent TKA.MethodsIn this prospective, double-blind, randomized placebo-controlled trial, 80 patients were randomized to the acetaminophen or control group. Patients in the acetaminophen group received celecoxib 400mg, pregabalin 150mg, and acetaminophen 325mg 2 hours before TKA. Patients in the control group received celecoxib, pregabalin, and placebo. Primary outcome was postoperative consumption of morphine hydrochloride used for rescue analgesia. Secondary outcomes included the time to the first rescue analgesia, postoperative pain as assessed by visual analogue scale (VAS), functional recovery as assessed by range of knee motion and ambulation distance, the time to hospital discharge, and complication rates.ResultsThere was no significant difference between the control group and the acetaminophen group in postoperative 0–24 h morphine consumption (average 11.3 mg vs. 12.3 mg, p = 0.445) and total morphine consumption (average 17.3 mg vs. 19.3 mg, p = 0.242). There was no significant difference in the time to the first rescue analgesia, postoperative VAS pain scores at any time points, postoperative functional recovery of knee, and the time to hospital discharge. The two groups had a similar occurrence of postoperative complications.ConclusionsThe addition of acetaminophen to preoperative preemptive multimodal analgesia could not reduce postoperative morphine consumption or improve pain relief. Orthopedic surgeons should reconsider routine use of preemptive acetaminophen in TKA.Trial registration: The study was prospectively registered on Chinese Clinical Trial Registry (identification number: ChiCTR2100052732) on 04/11/2021. http://www.chictr.org.cn/edit.aspx?pid=136730&htm=4