Last reviewed 2026-04-22 · How we verify

Interscalene Nerve Block

An interscalene nerve block is a regional anesthesia technique that injects local anesthetic around the upper trunk of the brachial plexus to numb the shoulder and upper arm.

An interscalene nerve block is a regional anesthesia technique that injects local anesthetic around the upper trunk of the brachial plexus to numb the shoulder and upper arm. Used for Anesthesia for shoulder surgery (rotator cuff repair, shoulder arthroplasty), Anesthesia for upper arm and hand surgery, Postoperative pain management following shoulder procedures.

At a glance

Mechanism of action

The procedure targets the brachial plexus nerves at the interscalene groove (between the anterior and middle scalene muscles in the neck) to deliver local anesthetic directly to nerve tissue. This blocks sensory and motor signals from the shoulder, upper arm, and hand, providing anesthesia for surgical procedures and postoperative pain management. The technique is performed under ultrasound or landmark guidance and may be single-shot or continuous (catheter-based).

Approved indications

• Anesthesia for shoulder surgery (rotator cuff repair, shoulder arthroplasty)
• Anesthesia for upper arm and hand surgery
• Postoperative pain management following shoulder procedures

Common side effects

• Horner's syndrome (ptosis, miosis, anhidrosis)
• Hoarseness or voice changes
• Dyspnea or respiratory compromise
• Phrenic nerve palsy
• Local anesthetic toxicity
• Nerve injury

Key clinical trials

• Shoulder Pericapsular Block Versus Interscalene Block in Arthroscopic Shoulder Surgery (NA)
• Comparison of Postoperative Analgesic Efficacy of Interscalene and Suprascapular Blocks Used in Arthroscopic Shoulder Surgery
• Diaphragm-Sparing Regional Anesthesia Techniques for Shoulder Surgery (NA)
• Comparison of the Effectiveness of USG-Guided Interscalene Block Versus Combined Interscalen-Suprascapular Block for Arthroscopic Shoulder Surgery (NA)
• Comparative Analgesia and Respiratory Effects of Shoulder Blocks (NA)
• Pericapsular Nerve Block Versus Interscalene Nerve Block for Acute Pain Management in Shoulder Arthroscopy (NA)
• Research of Brachial Plexus Anatomy
• Comparison of the Interscalene Block Alone Versus Combined With Superior Truncus Block During Shoulder Surgery in Diaphragmatic Function (NA)

Primary sources

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