Shoulder surgery often produces significant postoperative pain due to the dense innervation of the shoulder joint and surrounding musculature. Effective anesthesia and analgesia are therefore essential not only for patient comfort but also for facilitating early rehabilitation and improved outcomes. Among various regional anesthesia techniques, the interscalene brachial plexus block is widely regarded as the preferred nerve block for shoulder surgery. This approach provides targeted pain control, minimizes opioid use, and enhances recovery when performed safely and appropriately.
The shoulder receives its sensory and motor innervation primarily from the upper roots of the brachial plexus, specifically the C5, C6, and C7 nerve roots. These nerves form the superior and middle trunks of the plexus, which carry fibers to the suprascapular, axillary, and lateral pectoral nerves—all of which are critical to shoulder sensation and movement. The interscalene block targets these nerve roots as they pass between the anterior and middle scalene muscles in the neck. By depositing a local anesthetic at this level, the block interrupts sensory transmission from the shoulder joint and upper arm, producing profound analgesia prior to and following surgery. Its area of coverage makes it the preferred option for shoulder surgery that utilizes a peripheral nerve block 1–3.
The interscalene block can be performed using anatomical landmarks, nerve stimulation, or, more commonly, ultrasound guidance. Ultrasound allows direct visualization of the brachial plexus, surrounding muscles, and vascular structures, greatly improving accuracy and reducing complications. Once the target nerves are identified, a small-gauge needle is advanced into the interscalene groove, and a local anesthetic such as ropivacaine or bupivacaine is slowly injected.
For extended pain relief, a continuous catheter may be placed at the site, allowing an infusion of dilute local anesthetic for up to 48 hours postoperatively. This continuous technique is particularly beneficial for major shoulder procedures such as rotator cuff repair or total shoulder arthroplasty, where pain can persist beyond the immediate postoperative period. General anesthesia is often used in conjunction with the interscalene block to provide optimal surgical conditions, but the block remains the cornerstone of postoperative pain management 4–8.
The primary benefit of the interscalene block is its superior analgesia. Patients experience markedly reduced pain scores, decreased opioid consumption, and faster return to function compared with systemic analgesia alone. The block also helps reduce opioid use and the occurrence of associated side effects, such as nausea, vomiting, and sedation, thereby contributing to higher patient satisfaction and shorter hospital stays.
However, the technique is not without limitations. One side effect that anesthesiologists must be on alert for is transient phrenic nerve blockade (which can lead to partial paralysis). Although usually well tolerated in healthy individuals, it can pose a risk for patients with preexisting respiratory compromise, in particular. Other potential complications include hoarseness from recurrent laryngeal nerve involvement, Horner’s syndrome, or nerve injury, though these are rare when performed under ultrasound guidance. In such cases, alternative approaches like the supraclavicular or suprascapular-axillary block combination may be considered to preserve diaphragmatic function 9–13.
While multiple options exist, in general, the interscalene brachial plexus nerve block remains the preferred option for shoulder surgery, making it invaluable in both ambulatory and inpatient settings.
References
1. Millett, P. J., van der Meijden, O. A. J. & Gaskill, T. Surgical anatomy of the shoulder. Instr Course Lect 61, 87–95 (2012).
2. What Is a Shoulder Joint? Cleveland Clinic https://my.clevelandclinic.org/health/body/24780-shoulder-joint.
3. Miniato, M. A., Anand, P. & Varacallo, M. A. Anatomy, Shoulder and Upper Limb, Shoulder. in StatPearls (StatPearls Publishing, Treasure Island (FL), 2025).
4. How I Do It: Ultrasound-Guided Combined Suprascapular and Axillary Nerve Block. ASRA Pain Medicine https://asra.com/news-publications/asra-updates/blog-landing/legacy-b-blog-posts/2019/08/07/how-i-do-it-ultrasound-guided-combined-suprascapular-and-axillary-nerve-block.
5. Conroy, P. H. & Awad, I. T. Ultrasound-guided blocks for shoulder surgery. Curr Opin Anaesthesiol 24, 638–643 (2011). DOI: 10.1097/ACO.0b013e32834c155f
6. Hewson, D. W., Oldman, M. & Bedforth, N. M. Regional anaesthesia for shoulder surgery. BJA Education 19, 98–104 (2019). DOI: 10.1016/j.bjae.2018.12.004
7. Harley, J. D., Harrison, A. K. & Rao, A. J. An update on regional anesthesia in shoulder surgery: a narrative review. Annals of Joint 10, (2025). DOI: 10.21037/aoj-24-64
8. Fisher, B., Martusiewicz, A., Wiater, B. & Wiater, J. M. Optimizing Outpatient Shoulder Surgery: A Review of Anesthetic Options. J Am Acad Orthop Surg 33, e1–e10 (2025). DOI: 10.5435/JAAOS-D-24-00156
9. Operater. Interscalene Brachial Plexus Block – Landmarks and Nerve Stimulator Technique. NYSORA https://www.nysora.com/techniques/upper-extremity/intescalene/interscalene-brachial-plexus-block/ (2018).
10. Zisquit, J. & Nedeff, N. Interscalene Block. in StatPearls (StatPearls Publishing, Treasure Island (FL), 2025).
11. Staples, D. Interscalene brachial plexus block for shoulder surgery | The Rotherham NHS Foundation Trust. https://www.therotherhamft.nhs.uk/patients-and-visitors/patient-information/interscalene-brachial-plexus-block.
12. Kang, R. & Ko, J. S. Recent updates on interscalene brachial plexus block for shoulder surgery. Anesth Pain Med (Seoul) 18, 5–10 (2023). DOI: 10.17085/apm.22254
13. Orekondi, S. S. et al. P115 Interscalene brachial plexus block for shoulder arthroscopic procedures 3 years’ experience from a tertiary hospital in Qatar. Reg Anesth Pain Med 49, A276–A277 (2024). DOI: 10.1136/rapm-2024-ESRA.430
