Case Report:

A 49-year-old female with past medical history including major depression, anxiety, OSA, and chronic bilateral lower extremity pain secondary to complex regional pain syndrome type 1 stemming from a torn right ACL 20 years prior presents for right total knee arthroplasty. Her chronic pain is managed with gabapentin 600mg 3 times daily, ibuprofen 60mg 3 times daily, Hydrocodone 10mg/acetaminophen 325mg q6 hour as needed (usually less than once a week), tizanidine 6mg 3 times daily, yearly ketamine infusions, and an intrathecal pain pump containing fentanyl, clonidine and bupivacaine. For anxiety she takes clonazepam 2mg nightly and for depression she is on bupropion and desvenlafaxine.  She has had a spinal nerve stimulator in the past, but this has since been removed. Prior to her proposed operation, she presented to her outpatient pain management clinic where a transitional pain management plan was developed including a right sided lumbar sympathetic plexus nerve block performed three days before surgery. She was then admitted to the hospital two days prior to her  surgery for initiation of a ketamine infusion which was started at a dose of 10mg/hour before being increased to 20mg/hour on the day of surgery. On admission, she reported a 6/10 pain level described as a constant “gnawing” and burning sensation in her lower extremities that is consistent with her baseline pain. On the day of surgery, right sided femoral nerve block was performed with 30mL of 0.5% Ropivacaine and 4mg Dexamethasone in conjunction with the placement of a continuous femoral nerve catheter containing 0.2% Ropivacaine at 8mL/hour. Perioperatively, she received 300mg fentanyl, 30mg ketorolac, 3.5mg hydromorphone, and 20mg ketamine.