Newly Published
Pain Medicine  |   January 2020
Subomohyoid Anterior Suprascapular Block versus Interscalene Block for Arthroscopic Shoulder Surgery: A Multicenter Randomized Trial
Author Notes
  • From the Department of Anesthesiology and Pain Medicine, and the Ottawa Hospital Research Institute, University of Ottawa, Ottawa, Canada (F.W.A.); the Department of Anesthesia (F.W.A., D.N.W., R.B., A.M., V.W.S.C.), the Institute of Health Policy, Management, and Evaluation (D.N.W., A.L.), the Department of Medicine (A.L.), and the Dalla Lana School of Public Health (K.E.T.), University of Toronto, Toronto, Canada; the Li Ka Shing Knowledge Institute of St. Michael’s Hospital, University of Toronto, Toronto, Canada (F.W.A., D.N.W., A.L.); the Department of Anesthesia (D.N.W.), and the Department of Medicine (A.L.), St. Michael’s Hospital, Toronto, Canada; the Department of Anesthesia and Pain Management, University Health Network, Toronto, Canada (D.N.W., V.W.S.C.); the Department of Anesthesia, Women’s College Hospital, Toronto, Canada (R.B.); the Department of Anesthesia, North York General Hospital, Toronto, Canada (A.M.); the Department of Anesthesia, Wexner Medical Center, Ohio State University, Columbus, Ohio (N.H.); and the Applied Health Research Centre, Li Ka Shing Knowledge Institute of St. Michael’s Hospital, Toronto, Canada (K.E.T.).
  • Submitted for publication June 1, 2019. Accepted for publication December 17, 2019.
    Submitted for publication June 1, 2019. Accepted for publication December 17, 2019.×
  • Correspondence: Address correspondence to Dr. Abdallah: Ottawa Hospital General Campus, 501 Smyth Road, Ottawa, Ontario, K1H 8L6, Canada. FAbdallah@toh.ca. Information on purchasing reprints may be found at www.anesthesiology.org or on the masthead page at the beginning of this issue. Anesthesiology’s articles are made freely accessible to all readers, for personal use only, 6 months from the cover date of the issue.
Article Information
Pain Medicine / Pain Medicine / Pharmacology / Regional Anesthesia
Pain Medicine   |   January 2020
Subomohyoid Anterior Suprascapular Block versus Interscalene Block for Arthroscopic Shoulder Surgery: A Multicenter Randomized Trial
Anesthesiology Newly Published on January 22, 2020. doi:https://doi.org/10.1097/ALN.0000000000003132
Anesthesiology Newly Published on January 22, 2020. doi:https://doi.org/10.1097/ALN.0000000000003132
Abstract

Editor’s Perspective:

What We Already Know about This Topic:

  • Interscalene brachial plexus block is a commonly used procedure for shoulder surgery, but it can be associated with important complications

What This Article Tells Us That Is New:

  • Subomohyoid anterior suprascapular block is noninferior to interscalene block in providing analgesia for the first 24 h after shoulder surgery

  • Subomohyoid anterior suprascapular block does not appear to differ significantly from interscalene block in terms of superior trunk blockade or overall quality of recovery

Background: Interscalene brachial plexus block, the pain relief standard for shoulder surgery, is an invasive technique associated with important complications. The subomohyoid anterior suprascapular block is a potential alternative, but evidence of its comparative analgesic effect is sparse. The authors tested the hypothesis that anterior suprascapular block is noninferior to interscalene block for improving pain control after shoulder surgery. As a secondary objective, the authors evaluated the success of superior trunk (C5–C6 dermatomes) block with suprascapular block.

Methods: In this multicenter double-blind noninferiority randomized trial, 140 patients undergoing shoulder surgery were randomized to either interscalene or anterior suprascapular block with 15 ml of ropivacaine 0.5% and epinephrine. The primary outcome was area under the curve of postoperative visual analog scale pain scores during the first 24 h postoperatively. The 90% CI for the difference (interscalene-suprascapular) was compared against a –4.4-U noninferiority margin. Secondary outcomes included presence of superior trunk blockade, pain scores at individual time points, opioid consumption, time to first analgesic request, opioid-related side-effects, and quality of recovery.

Results: A total of 136 patients were included in the analysis. The mean difference (90% CI) in area under the curve of pain scores for the (interscalene-suprascapular) comparison was –0.3 U (–0.8 to 0.12), exceeding the noninferiority margin of –4.4 U and demonstrating noninferiority of suprascapular block. The risk ratio (95% CI) of combined superior trunk (C5–C6 dermatomes) blockade was 0.98 (0.92 to 1.01), excluding any meaningful difference in superior trunk block success rates between the two groups. When differences in other analgesic outcomes existed, they were not clinically important.

Conclusions: The suprascapular block was noninferior to interscalene block with respect to improvement of postoperative pain control, and also for blockade of the superior trunk. These findings suggest that the suprascapular block consistently blocks the superior trunk and qualify it as an effective interscalene block alternative.