Randomized controlled trial on efficacy of single injection or continuous interscalene brachial plexus block on analgesia in patients having outpatient rotator cuff surgery.

Inclusion Criteria:

Patients who agree to participate in the study will be asked to sign the informed consent and the HIPAA form.

Inclusive criteria are:

• 18-75 years of age
• ASA physical status I-III
• BMI < 35 kg/m2

Exclusion Criteria:

• all open shoulder procedures
• patient having difficulty understanding the instruction on using the anesthetic infusion pump
• contraindications to administration of regional anesthesia (e.g., allergy to a local anesthetic, local infection and coagulopathy)
• significant neurologic disorders of the upper extremity
• psychiatric or cognitive disorders
• history of substance abuse or chronic opioid use