Effect of Adding Esketamine to Patient-Controlled Intravenous Analgesia on Rebound Pain After Interscalene Brachial Plexus Block: A Randomized Controlled Trial.
Ruipeng Zhong, Lanhua Zhong, Hua Zhu et al.
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In 30 seconds
This randomized controlled trial evaluated whether adding esketamine to postoperative patient-controlled intravenous analgesia (PCIA) reduces rebound pain after interscalene brachial plexus block in patients undergoing shoulder arthroscopy. Among 132 randomized patients, rebound pain occurred in 25.8% with esketamine-containing PCIA and 39.4% with PCIA without esketamine; the difference was not statistically significant (OR, 0.53; 95% CI, 0.39 to 1.09; P =0.095). Esketamine was associated with better scores on several secondary pain, sleep, and recovery outcomes, but their clinical relevance was uncertain.
Key findings
- Rebound pain incidence was 25.8% with esketamine versus 39.4% in controls (OR, 0.53; 95% CI, 0.39 to 1.09; P =0.095).
- Among patients with rebound pain, the esketamine group had lower modified rebound pain scores and shorter pain duration.
- Esketamine recipients had lower NRS scores at 12, 24, and 48 h, fewer PCIA demands, less rescue analgesic use, and higher QoR-15 and RCSQ scores (all P <0.05).
- The incidence of assessed adverse events did not differ significantly between groups.
Why it matters
Rebound pain can undermine the analgesic benefit of a peripheral nerve block. In this trial, adding esketamine did not establish a reduction in its incidence, although several secondary outcomes favored esketamine. The findings distinguish a possible improvement in postoperative pain experience and recovery from evidence that the intervention prevents rebound pain.
What to keep in mind
The trial did not demonstrate a significant reduction in rebound pain incidence, and the clinical relevance of improvements in secondary outcomes was uncertain. The authors call for further multicenter studies.