- Design
- Blinded randomised non-inferiority trial
- Population
- 70 adults having knee arthroscopy with femoral nerve block, China
- Primary outcome
- QoR-15 at 24 hours
- Effect
- Difference 1.45 (−1.60 to 4.51); PONV 21.2% vs 48.5%
A patient- and assessor-blinded randomised trial in China allocated 70 adults having elective knee arthroscopy with femoral nerve block to opioid-free anaesthesia based on dexmedetomidine and esketamine, or to opioid-based anaesthesia. The primary outcome was quality of recovery (QoR-15) at 24 hours, with a non-inferiority margin of 6 points.
QoR-15 scores were similar (mean difference 1.45, 95% CI −1.60 to 4.51), establishing non-inferiority. Opioid-free anaesthesia more than halved nausea and vomiting (21.2% vs 48.5%), but early pain was higher, rescue analgesia came sooner and rescue opioid use was greater. Two patients had postoperative bradycardia in the opioid-free arm.
Opioid-free techniques are not a free lunch. For patients at high risk of nausea, they may be worth it; for others, the early pain cost may outweigh the gain. Plan rescue analgesia in advance either way.
- Consider opioid-free anaesthesia for patients at high risk of postoperative nausea and vomiting
- Plan rescue analgesia in recovery; early pain was higher without intraoperative opioid
- Monitor heart rate after dexmedetomidine-based techniques
- Explain the trade-off to patients choosing between approaches
Why it matters
Shows the practical trade-off clinicians face when choosing opioid-free techniques.
The statistics, in plain English
Non-inferiority means quality of recovery was not meaningfully worse; the confidence interval stayed well above the −6-point margin. With 70 patients the trial cannot reliably assess rarer harms such as bradycardia.
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