Ultrasound guided interscalene nerve blockade with local anesthesia is a standard regional anesthetic technique for providing postoperative analgesia during shoulder arthroscopy and wide variety of shoulder procedures. There is a paucity of data regarding the effects of shoulder arthroscopy on ultrasound image quality, including the effects of muscle mobilization and the use of large volume irrigation and subsequent tissue absorption, though increased neck circumference and airway edema are known complications of arthroscopic shoulder procedures.

The objective of the study is to determine if there is a difference in ultrasound image quality of the interscalene block anatomy, by Likert scale, pre- versus post-operatively in a cohort of patients undergoing shoulder arthroscopy who routinely receive blockade of the brachial plexus for postoperative analgesia. Further, if there are differences in imaging quality, correlations with surgical and patient factors will be studied.

Inclusion Criteria:

• Subject is undergoing shoulder procedures involving arthroscopy
• Subject has consented to interscalene blockade for postoperative analgesia

Exclusion Criteria:

• Patient refusal
• Contraindications to interscalene blockade, including significant pulmonary insufficiency, hemi-diaphragmatic paralysis, brachial plexus or degenerative neuropathy
• Allergy to proposed local anesthetic medication\
• Severe cervical spine disease.
• BMI >40 kg/m2
• Neck Circumference > 50cm
• Failed preoperative interscalene blockade
• Patients known to be currently pregnant or actively breastfeeding
• Patients where English is a language barrier

Adult patients (>18 years of age) undergoing shoulder procedures involving arthroscopy who have consented to interscalene blockade for postoperative analgesia.