Opioid-free vs. opioid-inclusive anaesthesia with or without regional anaesthesia for postoperative pain: a systematic review with network meta-analysis of randomised controlled trials.

Summary

This network meta-analysis of 885 randomized trials across 59 countries shows that regional anesthesia is the primary driver of improved postoperative pain control, with minimal added benefit from intraoperative opioids when regional techniques are used. Opioid-free strategies, particularly when combined with regional anesthesia, reduced postoperative nausea and vomiting and postoperative opioid requirements.

Key Findings

• Regional anesthesia–containing strategies ranked highest for postoperative pain at 2, 12, and 48 hours (SUCRA 93%, 85%, 75%; low certainty).
• With regional anesthesia, differences between opioid-free and opioid-inclusive techniques were minimal (moderate certainty).
• Opioid-free plus regional anesthesia reduced postoperative opioid consumption and postoperative nausea and vomiting.
• Without regional anesthesia, both pain scores and opioid requirements were higher regardless of intraoperative opioid strategy.

Clinical Implications

Prioritize regional anesthesia whenever feasible; when regional coverage is adequate, consider opioid-free intraoperative strategies to reduce PONV and postoperative opioid use without compromising analgesia. Focus quality improvement on optimizing regional block selection and coverage rather than intraoperative opioid titration.

Limitations

• Certainty for some pain outcomes was low; clinical and methodological heterogeneity likely substantial
• Variability in regional anesthesia types, coverage, and quality across trials; potential publication bias

Future Directions

Prospective, standardized trials to define optimal regional techniques and coverage; assess outcomes beyond pain (functional recovery, PONV, opioid-related adverse events), and evaluate cost-effectiveness of opioid-free pathways with robust ERAS integration.