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

Not Applicable

Terminated

Brief Summary: 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.

Detailed Description: 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).

Recruitment & Eligibility

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

Arm && Interventions

Group	Intervention	Description
Placebo	normal saline (placebo)	3-7 days of perineural normal saline infusion
Active	perineural ropivacaine	3-7 days of perineural local anesthetic infusion

Primary Outcome Measures

Name	Time	Method
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	Week 4

Secondary Outcome Measures

Name	Time	Method
Emotional Functioning · Beck Depression Inventory	pre-intervention; and then day 28 and 365 post-intervention
Nervous System Reorganization [if Patient Elected to Participate in the MRI Procedures] · MRI Procedure	pre-intervention; and then 8 and 28 days post-intervention
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	Day 8, Day 28, Month 12
Physical Functioning · Brief Pain Inventory	pre-intervention, then days 1, 3, 8, 28, 84, and 365