RESUMO
BACKGROUND: Ketamine, a potent analgesic and N-methyl-D-aspartate-(NMDA)-receptor antagonist, improves analgesic outcomes in patients with complex regional pain syndrome (CRPS). The NMDA receptor has also been implicated in opioid withdrawal. The use of ketamine to assist with a rapid opioid taper in the setting of CRPS has not been previously described. CASE: We present a case in which a 5-day continuous ketamine infusion was utilized in a robust multimodal analgesia regimen in combination with cognitive behavioral therapy (CBT) to successfully taper a patient with complex regional pain syndrome (CRPS) who was taking 330 mg of daily morphine equivalents completely off of opioids, minimize withdrawal symptoms, and produce sustained results. DISCUSSION: CRPS may involve catecholamine hypersensitivity and central sensitization and can be notoriously challenging to treat by itself even outside of the context of an opioid taper. The patient we describe here received one additional 5-day infusion at 6 months and remained opioid-free while experiencing a major improvement in function and lifestyle that he still maintains. This was possible through a combination of aggressive inpatient management with ketamine as the centerpiece, followed by consistent outpatient CBT to maintain results without the need for a return to opioids. This combination has previously not been described in the setting of a rapid opioid taper and this patient's underlying CRPS made it all the more remarkable.
