Randomized Controlled Trial of Ketamine Infusion With Continuous Epidural Infusion for Treatment of Complex Regional Pain Syndrome

INCLUSION CRITERIA:

* Patients must meet the Budapest CRPS criteria, including two or more symptom categories and three or more sign categories (as previously documented by a pain management physician or neurologist, or as observed on initial neurologic examination by the study investigator)
* Patients must have trialed at least three of the following therapies without relief judged adequate by the patient:
* Anti-depressants
* Anti-seizure medication
* Muscle relaxants
* Nerve blocks (somatic or sympathetic)
* Non-opioid analgesics
* Non-steroidal anti-inflammatory drugs
* Opioid analgesics
* Physical therapy
* Spinal cord stimulator trial
* Patients of either gender between the ages of 18 and 65 inclusive
* Patient report of a NRS pain score of at least 5 in at least two out-patient pain management physician clinic visits

EXCLUSION CRITERIA:

* Patients younger than 18 or older than 65
* Patients who:
* Are pregnant
* Are affected with glaucoma
* Are affected with thyrotoxicosis
* Are lactating
* Are on chronic anticoagulation therapy
* Have autonomic dysfunction with hemodynamic instability
* Have cardiac rhythm disturbance
* Have cerebrovascular disease
* Have conditions that would preclude central line placement
* Have conditions that would preclude epidural catheter placement
* Have congestive heart failure
* Have coronary artery disease
* Have creatinine level above 1.5
* Have electrolyte disturbance
* Have had previous reaction to IV contrast dye
* Have history of deep vein thrombosis
* Have history of systemic administration of ketamine for the treatment of pain
* Have liver disease
* Have known history of psychosis, significant thought disorder, or untreated (bipolar disorder depression or anxiety disorder ok)
* Have uncontrolled hypertension
* Any patient who is unable to provide consent due to cognitive difficulties
* Non-English speakers, as some of the instruments are only validated in English
* Patients with active litigation or workers compensation related to CRPS
* Patients with an intolerance or allergy to any medication planned as a component of the study
* Patients with known history of illegal drug use or alcohol dependence