Analgesic Efficacy of Interscalene Nerve Block Versus Local Infiltration Analgesia Following Total Shoulder Arthroplasty

Inclusion criteria

• Adult patients with an American Society of Anesthesiologists (ASA) physiological status I-III
• Patients presenting for unilateral primary total shoulder arthroplasty (includes anatomic and reverse total shoulder arthroplasty).
• Patients 18 years of age and older
• Able to provide informed consent for him or herself

Exclusion criteria

• Chronic pain syndromes such as fibromyalgia or complex regional pain syndrome
• Chronic opioid use (>1 mos) with oral morphine equivalents (OME) >5 mg/day OR acute opioid use (< 1 mos) with OME > 30 mg/day.
• Body mass index (BMI) > 45 kg/m2
• Severe drug allergy* to medications used in this study, including non-steroidal anti-inflammatory drugs (i.e. celecoxib and ketorolac), and local anesthetics.
• History of Malignant Hyperthermia.
• Major systemic medical problems such as:

• Pre-existing severe renal disorder defined as glomerular filtration rate (GFR) <50 units/m2 (if labs are available), currently on dialysis, or highly suspected based on history.
• Severe hepatic disorder defined as current or past diagnosis of acute/subacute necrosis of liver, acute hepatic failure, chronic liver disease, cirrhosis (primary biliary cirrhosis), chronic hepatitis/toxic hepatitis, liver abscess, hepatic coma, hepatorenal syndrome, other disorders of liver
• Pre-existing medical history of moderate to severe pulmonary disease (obstructive and/or restrictive), use of home oxygen, preoperative baseline oxygen saturation < 94% on room air, forced expiratory volume in 1 second (FEV 1) < 60% of predicted value (obstructive disease), vital capacity (VC) or total lung capacity (TLC) < 70% predicted value (restrictive disease).37
• History of contralateral hemidiaphragmatic dysfunction (e.g., paralysis) or phrenic nerve injury.
• Contraindication to a regional anesthesia technique (e.g., preexisting neuropathy+ in the operative extremity, coagulopathy, sepsis, infection at site of injection, uncooperative, refusal, anticoagulation medications not held within appropriate time frame per American Society of Regional Anesthesia (ASRA) guidelines.
• Previous contralateral total shoulder replacement managed with regional anesthetic nerve block or periarticular injection/intraarticular injection within the previous 12 months.
• Known to be currently pregnant or actively breastfeeding++

• ++ Patients that have a previous history of menopause, hysterectomy, or tubal ligation will not be required to perform a pregnancy test.
• Impaired cognition