Interscalene block (ISB) can provide pain relief after
shoulder surgery, but a reliable quantification of its analgesic benefits is lacking. This systematic review of randomized and
quasi-randomized controlled trials published in Anesthesia and analgesia
examined the effect of single-shot
ISB on analgesic outcomes during the first 48 hours after shoulder surgery. They found that ISB provided effective analgesia up
to 6 hours with motion and 8 hours at rest after shoulder surgery, with no demonstrable benefits thereafter. Patients who receive
an ISB can suffer rebound pain at 24 hours but later experience similar pain severity compared with those who do not receive an ISB.
ISB reduced postoperative opioid consumption up to 12 hours, decreased postoperative nausea and vomiting at 24 hours, and expedited
postanesthesia care unit and hospital discharge. The type, dose, and volume of local anesthetic used did not affect the results.