Duration of Analgesic Effect for Ultrasound Guided Supraclavicular Blocks With the Addition of Buprenorphine to Local Anesthetic Solution

Inclusion Criteria: 1. American Society of Anesthesiologists (ASA) physical status 1-3 2. Age 18-79, inclusive 3. BMI \<36 kg/m\^2 4. Patient consenting to single injection brachial plexus nerve block as primary anesthetic for a procedure Exclusion Criteria: 1. Patients with coagulation disorders 2. Clinically significant pulmonary disease 3. Clinically significant cardiac disease 4. Neurologic deficit in surgical extremity 5. Allergy to bupivacaine or buprenorphine 6. Intolerance of narcotics 7. Local infection over intended area of needle insertion 8. Hepatic failure or renal failure 9. Significant psychiatric disease, including drug abuse 10. Seizure disorder 11. Possible pregnancy or lactation by patient report 12. Use of narcotic medication greater than 2 times a week for greater than 1 week. 13. Patients for whom the surgeon requests a shorter-acting block