Interscalene Block Versus Anterior Suprascapular Nerve Block for Shoulder Surgery in the Outpatient Setting: Postoperative Pain Managemente and Quality of Recovery With a Multimodal Analgesic Strategy

Shoulder surgery in the outpatient setting requires an anesthetic and analgesic strategy that provides effective postoperative pain control while allowing early recovery and safe discharge. Unilateral shoulder procedures may be associated with moderate to severe postoperative pain, particularly during the first 24 to 48 hours after surgery. In this context, regional anesthesia is an important component of perioperative pain management because it can reduce postoperative pain, decrease the need for opioid analgesics, limit postoperative nausea and vomiting, and facilitate early rehabilitation and recovery.

The interscalene brachial plexus block (ISB) is commonly used for postoperative analgesia after shoulder surgery and is considered one of the most effective regional anesthesia techniques for this indication. However, ISB may be associated with block-related adverse effects, including variable phrenic nerve involvement with diaphragmatic impairment, dyspnea, Horner syndrome, hoarseness, and prolonged motor block of the upper limb. These effects may be particularly relevant in the outpatient setting, where delayed discharge, unplanned admission, or reduced quality of recovery may occur if adverse effects persist after surgery.

The anterior suprascapular nerve block (SSNB-A) has been proposed as a regional anesthesia technique for shoulder surgery that may provide effective analgesia while potentially reducing some of the adverse effects associated with ISB. The suprascapular nerve contributes substantially to the sensory innervation of the shoulder. The anterior approach targets the nerve in the supraclavicular region and may also allow local anesthetic spread toward relevant components of the superior trunk region involved in shoulder innervation. Available evidence suggests that SSNB-A may provide postoperative analgesia comparable to ISB in selected shoulder procedures, with a potentially more favorable side-effect profile.

This study is a prospective, monocentric, randomized, single-blind, noninferiority trial comparing SSNB-A with ISB for postoperative analgesia in adult patients undergoing unilateral shoulder surgery in the outpatient setting. Participants are randomized to receive either an ultrasound-guided interscalene block or an ultrasound-guided anterior suprascapular nerve block before surgery. Randomization is performed shortly before the procedure using block randomization in order to ensure balanced allocation between the two study groups.

Eligible participants are adult patients scheduled for unilateral shoulder surgery in the outpatient setting under general anesthesia. Surgical procedures may include long head of biceps tenotomy, biceps anchor repair, Bankart procedure, rotator cuff repair with or without biological membrane augmentation, subacromial decompression, acromioplasty, and acromioclavicular stabilization. Participants are screened according to predefined inclusion and exclusion criteria. Exclusion criteria include contraindications to regional anesthesia, allergy to local anesthetics or study analgesic drugs, known neuropathy or sensory or motor deficits in the surgical area or block territory, severe obesity, severe chronic obstructive pulmonary disease, pregnancy, known phrenic nerve paralysis with diaphragmatic paralysis, chronic opioid use, severe chronic pain, and inability or unwillingness to follow the postoperative analgesic protocol.