Opioid-free and opioid-sparing anesthesia for postoperative pain management: systematic review

Abstract

Background: Opioid-free anesthesia (OFA) and opioid-sparing anesthesia (OSA) reduce postoperative opioid exposure and maintain analgesia and recovery quality. Methods: We conducted a PRISMA guided systematic review of original comparative studies evaluating OFA, OSA versus opioid-based anesthesia. We searched major biomedical databases and trial registries for adult surgical patients receiving general anesthesia. Outcomes include, postoperative pain scores, opioid consumption, rescue analgesia, postoperative nausea and vomiting (PONV), and quality of recovery measures. Two reviewers screened studies, extracted data, and assessed risk of bias independently. Results: we include 6 randomized controlled trials in laparoscopic cholecystectomy, gynecologic laparoscopy, video assisted thoracic surgery, bariatric surgery, breast surgery, and hysterectomy. OFA, OSA regimens commonly incorporated dexmedetomidine with ketamine, esketamine and, or intravenous lidocaine, often within multimodal pathways. Compared with opioid based anesthesia, OFA, OSA reduced PONV or antiemetic requirements. Effects on pain intensity and postoperative opioid use were variable: several trials reported lower early rescue analgesia and, or reduced morphine equivalent consumption, whereas others showed no significant differences.  Conclusion: OFA, OSA were reliable for reducing opioid related adverse effects, mainly PONV, and support faster functional recovery. Analgesic benefits are protocol dependent. Standardized regimens and outcome reporting are needed to identify patients and procedures most likely to benefit.