Intravenous Ketamine Administered as Patient Controlled Analgesia and Continuous Infusion for Central Pain Syndrome

Treatment of Central Pain Syndrome (CPS) is known to be extremely challenging. Current therapies are unsatisfactory as patients report only mild to moderate pain relief. We report a case of using ketamine as a patient-controlled analgesia (PCA) for the treatment of CPS. A 58-year-old male with CPS presented with severe generalized body pain refractory to multiple pharmacological interventions. He was started on a basal infusion rate at 0.3 mg/kg/h with a ketamine PCA bolus of 10 mg with a 10-minute lockout period. Over the next 7 days, the basal infusion rate was titrated up to 2.1 mg/kg/h relative to the number of times the patient pressed the PCA. At the end of the trial, the patient reported 0/10 pain with lightheadedness on the first day being the only side effect reported. He was discharged home with his regular pain regimen, with significant decrease in pain over the next few months. Rather than trying to establish a "one size fits all" protocol for ketamine infusions, this case illustrates a shift in pain management focus by allowing patients to self-titrate and demonstrates the potential for using ketamine PCA as a treatment option for CPS.