Rebound pain after interscalene brachial plexus block for shoulder surgery: a randomized clinical trial of the effect of different multimodal analgesia regimens.

Background: Rebound pain is characterized by sudden, significant acute postoperative pain occurring after the resolution of inter-scalene block (ISB); it affects the quality of recovery postoperatively. Dexamethasone increases ISB resolution time and decreases opioid consumption and the incidence of rebound pain.
Objective: Evaluate whether multimodal analgesia including intravenous dexamethasone administration with preoperative ISB reduces the incidence of rebound pain.
Design: Prospective, randomized, controlled trial.
Setting: Tertiary university hospital.
Sample Size: 60 patients.
Patients and Methods: Patients who underwent shoulder surgery under general anesthesia were assigned randomly to two different multimodal analgesia protocols. Thirty patients received 5 mg IV dexamethasone with non-steroid, paracetamol, and ISB with 15 mL 0.5% bupivacaine, while the control patients received the same regimen and ISB with 15 mL 0.5% bupivacaine without dexamethasone. Postoperative opioids were given to any patient on demand.
Main Outcomes Measures: Effect of IV dexamethasone on pain score and incidence of rebound pain after ISB resolution and postoperative opioid consumption at 0-48 hours, numerical pain rating scale (NPRS) scores, sleep scale scores, and quality of recovery-15 scores (QoR-15).
Results: The incidence of rebound pain was lower in the dexamethasone group than in the control group (73.3% and 30%, respectively, P =.001). NPRS scores after ISB resolution were lower in the dexamethasone group (5 ([4-7]), 8 ([5.75-8]), P <.001, respectively). Those who received IV dexamethasone had less sleep disturbances ( P <.001) and higher QoR-15 on day 1 ( P <.001) and day 7 ( P =.020) postoperatively.
Conclusions: IV dexamethasone added to the ISB block resulted in a lower incidence of rebound pain. In addition, better results were obtained in postoperative sleep quality and QoR-15.
Limitations: Single-center study.
Competing Interests: CONFLICT OF INTEREST: None.