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

Study Overview
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Brief Summary
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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
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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).

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

Conditions
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Amputation, Phantom Limb, Stump Pain

Intervention / Treatment
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* Drug: perineural ropivacaine
* Drug: normal saline (placebo)


Participation Criteria
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Eligibility Criteria
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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

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Active<br>3-7 days of perineural local anesthetic infusion | Drug: perineural ropivacaine<br>* ropivacaine 0.4%; the basal rate will be set at 7 mL/h<br>|
| Placebo Comparator: Placebo<br>3-7 days of perineural normal saline infusion | Drug: normal saline (placebo)<br>* the basal rate will be set at 7 mL/h<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 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

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Physical Functioning · Brief Pain Inventory |  | pre-intervention, then days 1, 3, 8, 28, 84, and 365 | 
| 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 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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pain, phantom limb, stump pain, catheter, nerve block, peripheral nerve block, NMCSD, Post-Amputation Phantom Limb or Stump Pain