Naval Medical Center San Diego (NMCSD) - Ambulatory Continuous Peripheral Nerve Blocks for Treatment of Post-Amputation Phantom Limb and Stump Pain

Naval Medical Center San Diego (NMCSD) - Ambulatory Continuous Peripheral Nerve Blocks for Treatment of Post-Amputation Phantom Limb and Stump Pain

Ambulatory Continuous Peripheral Nerve Blocks for Treatment of Post-Amputation Phantom Limb and Stump Pain

The purpose of this research study is to determine if putting local anesthetic-or numbing medication-through one or two tiny tube(s) placed next to the nerves that go to an amputated limb will decrease phantom limb and/or stump pain.

Specific Aim 1: To determine if, compared with current standard-of-care treatment, the addition of an ambulatory continuous peripheral nerve block decreases post-amputation phantom limb and stump pain. Hypothesis 1: Following upper or lower extremity amputation, phantom limb and/or stump pain will be significantly decreased four weeks following a multiple-day ambulatory continuous peripheral nerve block as compared with patients receiving standard-of-care treatment (as measured on the 11-point numeric rating scale). Specific Aim 2: To investigate the possible relationship between the addition of a multiple-day ambulatory continuous peripheral nerve block to standard-of-care treatment of post-amputation phantom limb and/or stump pain and cortical reorganization. Hypothesis 2: Following upper or lower extremity amputation with subsequent phantom limb pain/sensation and/or stump pain, the addition of a multiple-day ambulatory continuous peripheral nerve block to standard-of-care treatment will result in cortical reorganization during and four-weeks following the perineural infusion (as measured by MRI).

pain, phantom limb, stump pain, catheter, nerve block, peripheral nerve block, NMCSD, Post-Amputation Phantom Limb or Stump Pain

Primary Analysis Will Compare the Two Treatment Groups for the Phantom Limb/Stump Pain Change From Baseline to 4 Weeks Following the Initial Catheter Placement

Nervous System Reorganization [if Patient Elected to Participate in the MRI Procedures] · MRI Procedure

Pain · 11-point Numeric Rating Scale of Pain Intensity · Usage of Baseline and Rescue Analgesics in Previous 24 Hours · Patient Global Impression of Change Scale

Inclusion Criteria: previous upper or lower limb amputation including at least one metacarpal or metatarsal bone, respectively age 18 years or older phantom limb and/or stump pain described as at least a 2 on the NRS for the previous week [and pain occurring on a weekly basis over the previous month] willing to have an ambulatory perineural infusion for 6 days willing to avoid additional "new" analgesic interventions from 4 weeks prior to at least 4 weeks following catheter placement, and preferably to 6 months following catheter placement the availability of a "caretaker" who will transport the subject home following the procedure and remain with the subject for the first night of the infusion Exclusion Criteria: known hepatic or renal insufficiency allergy to the study medications possessing a contraindication to perineural catheter placement or perineural local anesthetic infusion