Interscalene Block Versus Supraclavicular Block for Shoulder Surgery

A Randomized Comparison Between Interscalene and Supraclavicular Brachial Plexus Blocks For Arthroscopic Shoulder Surgery

Interscalene brachial plexus block constitutes the analgesic criterion standard for shoulder surgery. However it is associated with a high incidence of hemidiaphragmatic paralysis (HDP) that may not be tolerated by patients with chronic pulmonary disease.

This randomized controlled trial will compare ultrasound-guided interscalene block (ISB) and supraclavicular block in patients undergoing arthroscopic shoulder surgery.

The main outcome is static pain at 30 minutes after arrival in the post anesthesia care unit (PACU) as measured by a numerical rate scale (NRS) from 0 to 10.

Our research hypothesis is that interscalene and supraclavicular blocks will result in equivalent postoperative analgesia at 30 minutes in the PACU. The equivalence margin is set at 2 points

Inclusion Criteria:

• Patients undergoing arthroscopic shoulder surgery
• American Society of Anesthesiologists classification 1-3
• Body mass index between 20 and 35

Exclusion Criteria:

• Adults who are unable to give their own consent
• Pre-existing neuropathy
• Coagulopathy
• Obstructive or restrictive pulmonary disease
• Renal failure
• Hepatic failure
• Allergy to local anesthetics
• Pregnancy
• Prior surgery in the corresponding side of the neck or supraclavicular fossa
• Chronic pain syndromes requiring opioid intake at home