Continuous Interscalene Blocks and Rebound Pain

The primary objectives of this present study are to examine whether a continuous interscalene block of a total duration of 48 hours reduces the incidence of rebound pain comparatively to single-shot interscalene block, through the evaluation of the NRS scores at rest and on movement in the postoperative period at 24, 48, 72 and 96 hours as well as the total opioid consumption in the same timeframe for patients undergoing total shoulder arthroplasty.

Rebound pain has been defined in some studies as the "the transition from well-controlled pain (numerical rating scale \[NRS\] ≤3) while the block is working to severe pain (NRS ≥7) within 24 h of block performance."