IPACK Study in Total Knee Arthroplasty Patients

Inclusion criteria:

* English-speaking;
* Age 18 - 85;
* BMI ≤ 38;
* Undergoing unilateral primary total knee arthroplasty surgery.

Exclusion criteria:

* inability to give informed consent
* patient refusal
* pregnancy, patients who are breastfeeding
* contraindication to nerve blocks or multimodal analgesia
* contraindication or hypersensitivity to any of the study drugs (celecoxib, acetaminophen, morphine, ropivacaine, bupivacaine, ketamine, dexmedetomidine, dexamethasone, ketorolac, epinephrine, sulfonamides)
* chronic pain disorders (\> 50 mg oral morphine equivalence per day at time of recruitment)
* medical or recreational use of marijuana and substance abuse (e.g., alcoholism),
* complications after surgery that result in discharge to a location other than home
* severe cardiovascular diseases e.g., heart failure, significant dysrhythmias; uncontrolled low blood pressure e.g., systolic blood pressure ≤ 100 mm Hg while on antihypertensive medication(s)
* respiratory diseases e.g., severe asthma, urticaria, or allergic-type reactions after taking acetylsalicylic acid (ASA) or other NSAIDs; severe acute or chronic respiratory disease and obstructive airway
* severe or active liver disease
* severe inflammatory bowel disease
* severe renal impairment (creatinine clearance \<30 mL/min)
* uncontrolled diabetes (type 1 or 2)
* active bleeding condition (e.g., postoperative or gastro-intestinal bleeding)
* severe psychiatric disorders and intake of monoamine oxidase inhibitors
* neurologic disorders (e.g., operative extremity neuropathy, delirium tremens, uncontrolled convulsive disorders, increased cerebrospinal or intracranial pressure)