Design: Randomised, patient- and assessor-blinded, non-inferiority trial
Population: 70 adults having elective knee arthroscopy with femoral nerve block
Primary outcome: Quality of Recovery-15 at 24 hours
Effect: Difference 1.45 (95% CI −1.60 to 4.51); nausea 21.2% vs 48.5%

In a blinded trial, 70 adults having elective knee arthroscopy with a femoral nerve block were randomised to opioid-free anaesthesia with dexmedetomidine and esketamine, or opioid-based anaesthesia.

Recovery quality at 24 hours was non-inferior (QoR-15 mean difference 1.45, 95% CI −1.60 to 4.51). Nausea and vomiting fell from 48.5% to 21.2% (RR 0.44, 95% CI 0.21 to 0.92). But the opioid-free group had more early pain, needed rescue analgesia sooner (HR 2.11) and used slightly more rescue opioid. Two patients had bradycardia.

Opioid-free anaesthesia trades nausea for early pain. Whether that is a good trade depends on the patient — attractive for someone with severe past nausea, less so where early pain will delay discharge.

Consider opioid-free anaesthesia for arthroscopy patients with a history of severe postoperative nausea
Plan early rescue analgesia, as pain may arrive sooner
Watch heart rate after dexmedetomidine
Agree the approach with your anaesthetic team rather than requesting it routinely

Why it matters

It shows the trade-off clearly: less nausea is bought with earlier pain.

The statistics, in plain English

Non-inferior means opioid-free anaesthesia was not worse by more than a pre-set 6-point margin. The nausea reduction is large but the interval is wide (0.21 to 0.92) because the trial was small.