A Novel Use of Epidural Continuous Infusion in the Outpatient Setting

Abstract

Complex regional pain syndrome (CRPS, type 1 and type 2) describes a variety of disorders characterized by spontaneous or stimulus-induced pain that is disproportional to the inciting event and is accompanied by a myriad of autonomic and motor disturbances in highly variable combinations. Physical therapy, started as early as possible, is the mainstay of treatment, and pharmacological management and interventional techniques can be used to facilitate the participation in rehabilitation programs. Epidural local anesthetic (LA) use has been reported in the inpatient setting for the treatment of CRPS, but outpatient options are limited. Elastomeric pumps are commonly used for peripheral nerve blocks, postoperative pain, and palliative care in outpatient settings, but not described with epidural infusions. We describe a case of a cervical epidural catheter placed under fluoroscopy, utilizing an elastomeric pump in an outpatient setting. The system consists of a 270 mL elastomeric pump which is filled with 0.05% bupivicaine, delivering a constant 10 mL/hour. The system has a clamp that can be used by the patient to start and stop the infusion. A 23–year-old man presented with right hand/ thumb pain of approximately 2 months duration after an injury while cutting meat at work, resulting in an incomplete fracture of the proximal phalanx and injury to the extensor tendons of his thumb, which were repaired by orthopedics, and a thumb spica splint was placed. The patient described the pain as constant and stabbing, scored as a 5 – 6/10 on a numerical rating scale (NRS), and increased with any activities. The pain was associated with intermittent temperature changes, hypersensitivity to cold water, and occasional color changes. Physical examination was remarkable for a well-healed right thumb, mottling skin discoloration over the right thumb and hand, and hypersensitivity and allodynia to light touch and pinprick over the right hand and radial aspect of the wrist. Previous treatments consisted of physical therapy and oxycodone-acetaminophen as needed. A 3-week trial of pregabalin was tried, without improvement. After discussing alternative treatments (stellate ganglion block), the patient elected to try a local anesthetic (LA) infusion through a cervical epidural catheter. The epidural space was accessed at the C7-T1 level via left paramedian approach under fluoroscopy; the catheter was threaded 5 cm, and a 0.05% bupivacaine infusion was started via an elastomeric pump. On post-procedural day 4 the bupivacaine concentration was increased to 0.1% due to insufficient pain relief. The patient had good pain relief on day 8 and discontinued the infusion on day 16. The catheter was removed on day 18. We report a case of successful treatment of CRPS with an outpatient cervical epidural infusion. This modality has been used successfully for years at Geisinger Medical Center. Our goal is to bring attention to the outpatient use of elastomeric pumps for epidural infusion in the treatment of CRPS. The successful resolution of debilitating symptoms in this patient is encouraging, and the use of elastomeric pumps should be considered for further investigation into its efficacy in patients with CRPS. Key words: Complex regional pain syndrome (CRPS), cervical epidural, outpatient epidural infusion, tunneled epidural catheter