Phantom Limb Pain
Conditions
Keywords
phantom pain, traumatic limb amputation, amputees
Brief summary
When a limb is traumatically severed, pain perceived in the part of the body that no longer exists often develops. This is called phantom limb pain, and is different from stump pain, which is pain within the part of the limb that remains intact. Unfortunately, phantom pain resolves in only 16% of people, with the rest experiencing this pain for the remainder of the lives. There is currently no reliable treatment for phantom limb pain. The exact reason that phantom limb pain occurs is unclear, but when a nerve is cut-as happens with a traumatic amputation-changes occur in the brain and spinal cord that actually worsen with increasing phantom pain. These abnormal changes may often be corrected by putting local anesthetic-termed a peripheral nerve block-on the injured nerve, keeping any bad signals from reaching the brain, with resolution of the phantom limb pain. However, when the nerve block ends after a few hours, the phantom pain returns. But, this demonstrates that the brain abnormalities-and phantom pain-that occur with an amputation may be dependent upon the bad signals being sent from the injured nerve(s), suggesting that a very long peripheral nerve block-lasting many days rather than hours-may permanently reverse the abnormal changes in the brain, and provide lasting relief from phantom pain. Until recently, extending a peripheral nerve block beyond 16 hours was unrealistic. However, a treatment option called a continuous peripheral nerve block is now available. This technique involves the placement of a tiny tube-smaller than a piece of spaghetti-through the skin and next to the nerves supplying the amputated limb. The tiny tube may be placed with minimal discomfort in about 15 minutes. Numbing medicine called local anesthetic is then infused through the tube, blocking any signals that the injured nerve sends to the spinal cord and brain. Using a small, portable infusion pump, this prolonged nerve block may be provided in individuals' own homes. The ultimate objective of the proposed research study is to determine if a 6-day continuous peripheral nerve block provided at home is an effective treatment for persistent phantom limb pain following a traumatic limb amputation. The primary hypothesis (what the researchers predict) is that phantom limb pain intensity will be significantly decreased 4 weeks following treatment with a 6-day continuous peripheral nerve block.
Detailed description
Background. The combination of increased munitions force, use of improvised explosive devices, and casualty survival rates has resulted in a dramatic increase in the percentage of injured combat veterans living with a traumatic amputation. Of American Veteran amputees, 35-98% develop chronic, intractable pain perceived as being from the missing limb, a phenomenon termed phantom limb pain. This pain resolves in only 16% of afflicted individuals, and there is currently no reliable treatment. The etiology of phantom pain remains unclear, but evidence suggests that severing a nerve provokes changes in the spinal cord, thalamus, and cerebral cortex. When neural input from an amputated limb is blocked with local anesthetic (a peripheral nerve block), cortical abnormalities and phantom pain frequently resolve. However, when the single-injection nerve block resolves after a few hours, the phantom pain returns. These findings demonstrate that cortical abnormalities and phantom pain may be maintained from abnormal peripheral input, suggesting that a peripheral nerve block of extended duration-lasting many days rather than hours-may permanently reorganize cortical pain mapping, thus providing lasting relief from phantom pain. A continuous peripheral nerve block (CPNB) involves the percutaneous insertion of a catheter directly adjacent to the peripheral nerves supplying an affected limb. Local anesthetic infused via the catheter(s) induces a completely insensate extremity for as long as desired without any systemic side effects. Additionally, CPNB may be provided on an ambulatory basis using a small, portable pump to infuse the local anesthetic. Objective. To determine if ambulatory CPNB is an effective treatment for intractable phantom limb pain following a traumatic limb amputation. Previously-published small, uncontrolled series describe patients immediately following surgical amputation whose phantom limb pain dramatically decreased or completely resolved with CPNB. We have data from a randomized, double-masked, placebo-controlled, crossover pilot study suggesting great promise treating intractable phantom limb pain with ambulatory CPNB: participants (n=3) experienced no change in their phantom pain following a 6-day infusion of normal saline; however, with a 6-day CPNB of potent local anesthetic administered 4 months later, subjects (n=2; one patient returned to duty before crossover infusion) experienced complete resolution of their phantom limb pain. Within the 12-week follow-up period, one subject experienced no phantom pain recurrence; and the other subject reported mild pain occurring once each week of just a small fraction of his original pain. Specific Aims. The primary hypothesis is that phantom limb pain intensity will be significantly decreased 4 weeks following an ambulatory CPNB (as measured by the Numeric Rating Scale of the Brief Pain Inventory). Study Design. We propose a multicenter, randomized, double-masked, placebo-controlled, simultaneous parallel and crossover, human-subjects clinical trial. We will include subjects with an existing upper or lower amputation who experience phantom limb pain at least daily for the previous 4 weeks. Catheter site(s) will be determined by amputation location. Subjects will be randomized to receive one of two study solutions in a double-masked manner: either a local anesthetic (ropivacaine 0.5%) or placebo (normal saline). Catheters will be removed after 6 days of at-home infusion. Although not required, each subject has the option to return for the alternative treatment four weeks later (crossover infusion). The primary endpoint will be the difference in average phantom pain intensity at baseline and 4 weeks following the initial infusion as measured with the Numeric Rating Scale between treatment groups for the initial infusion. Major secondary endpoints will involve intra- and inter-subject comparisons of additional measures of pain and health-related quality-of-life. Clinical Impact. From 2001-2006, over 70% of all U.S. military casualties endured a major limb injury, with an amputation rate of 28% within Operation Enduring Freedom alone. Previous conflicts have left tens-of-thousands of United States Armed Forces Veterans with missing limbs. CPNB are now relatively ubiquitous within the United States, but applied nearly exclusively to provide acute post-injury/surgical analgesia. If the proposed study demonstrates that ambulatory CPNB is a reliable treatment for intractable phantom limb pain, the resulting impact in treating the consequences of traumatic amputation will be immediate and profound, as healthcare providers within the United States Armed Forces and Veterans Affairs Medical Centers already have expertise placing and managing perineural catheters. Currently, CPNB is provided exclusively in the acute setting-to treat pain immediately following a battlefield injury or surgery-and not chronic, intractable phantom limb pain. However, because there is little technical difference in providing CPNB for acute versus chronic pain, the thousands of U.S. Veterans and active duty personnel suffering from intractable phantom pain could be treated relatively easily, rapidly, and with negligible additional costs.
Interventions
DRUGPerineural infusion [continuous peripheral nerve block(s)]
Electronic, programmable, portable infusion pumps will be used to administer perineural study solution at fixed rates for over 6 days. Subjects will receive a total of 1,100 mL of study fluid from either one (upper extremity) or two (lower extremity) pump and external reservoir combinations. The continuous basal infusion rate will be determined by catheter location: femoral 2.5 mL/h; popliteal-sciatic 5 mL/h; and infraclavicular 7.5 mL/h (37.5 mg/h for both upper and lower extremity subjects). No patient-controlled bolus dose will be included. Subjects will have the option of returning 4-16 weeks later for a second infusion of the alternate treatment solution.
Sponsors
United States Department of Defense
University of California, San Diego
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
TREATMENT
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)
Masking description
The investigators originally planned to unmask the treatment groups following the completion of the statistical analysis (triple masked); but following the analysis using treatment A and treatment B labels, opted to wait to unmask the groups until the manuscript was drafted (quadruple masking).
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* 18 years of age or older * Upper or lower limb traumatic or surgical amputation at least 12 weeks prior to enrollment at or distal to the mid-humerus or hip (femoral head remaining), respectively; and including at least one metacarpal or metatarsal bone, respectively. * Experiencing at least moderate phantom limb pain (defined as 2 or higher on the numeric rating scale, NRS 0-10), at least three times each week for the previous 8 weeks. * Accepting of an ambulatory continuous peripheral nerve block for 6 days. * Willing to avoid changes to their analgesic regimen from 4 weeks prior to and at least 4 weeks following the initial catheter placement (preferably 4 weeks following the second/crossover catheter insertion as well). * Having a caretaker who will transport the subject home following the catheter insertion(s), and remain with the subject for the first night of the infusions.
Exclusion criteria
* Known renal insufficiency * Allergy to study medications * Pregnancy * Incarceration * Inability to communicate with the investigators * Morbid obesity (BMI greater than 40) * Comorbidity that results in moderate-to-severe functional limitation (ASA greater than 2) * Possessing any contraindication to ambulatory perineural catheter placement or perineural local anesthetic infusion: * Current infection * Immune-compromised status of any etiology * Uncontrolled anxiety/panic disorder * Inability to contact investigators during the perineural infusion
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Average Phantom Limb Pain Intensity 4 Weeks Following Initiation of an Ambulatory Continuous Peripheral Nerve Block (as Measured by the Numeric Rating Scale Within the Brief Pain Inventory) | 4 weeks following the initiation of the initial intervention. | Phantom pain will be assessed using a Numeric Rating Scale (NRS) as part of the Brief Pain Inventory (short form), with the average pain score designated as the primary endpoint. In addition, average and worst residual limb pain NRS will be recorded separately from the phantom pain scores. The NRS is a highly-sensitive measure of pain intensity with numbers ranging from 0 to 10, with zero equivalent to no pain and 10 equivalent to the worst imaginable pain. These data are 4 weeks after the initiation of the FIRST intervention (and not the optional crossover treatment). |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Perception of Well-being (as Measured With the Patient Global Impression of Change Scale). | 4 weeks following the initiation of the initial intervention | The Patient Global Impression of Change Scale is a 7-point ordinal scale requiring the subject to rate the current severity of their global situation as it relates to phantom limb pain (as defined by each individual) compared to their baseline. This scale has the words very much worse to the left by the number one, and very much improved to the right, adjacent to the number seven. The words no change are in the middle of the scale above the number four. The Patient Global Impression of Change Scale has been validated in over ten prospective trials, including studies specifically involving peripheral neuropathy. These data are from 4 weeks after the initiation of the FIRST intervention (and not the optional crossover treatment). |
| Physical and Emotional Functioning 4 Weeks Following Initiation of Intervention (as Measured With the Brief Pain Inventory Interference Domain). | 4 weeks following initiation of the initial intervention | The Brief Pain Inventory (interference sub scale) is an instrument that measures the interference with physical and emotional functioning using a 0-10 scale (0 = no interference; 10 = complete interference). The seven interference questions involve general activity, mood, walking ability, normal work activities (both inside and outside of the home), relationships, sleep, and enjoyment of life. The seven functioning questions can be added to produce an interference subscale (0-70). The use of both single items (e.g., mood) and the composite scores is supported. These data are from 4 weeks after the initiation of the FIRST intervention (and not the optional crossover treatment). |
| Depression 4 Weeks Following Initiation of Intervention (as Measured With the Beck Depression Inventory). | 4 weeks following initiation of the initial intervention | The Beck Depression Inventory is a 21-item instrument that measures characteristic symptoms and signs of depression, requires only a 5th grade comprehension level to adequately understand the questions, and demonstrates a high internal consistency (0.73-0.92, mean of 0.86), reliability and validity. Each of the 21 factors is rated on a 0-3 scale, and then summed to produce the total score of 0-63. Mild, moderate, and severe depression is defined with scores of 10-18, 19-29, and 30-63, respectively. This data is 4 weeks following the initiation of the initial intervention, and NOT the optional crossover treatment. |
Other
| Measure | Time frame | Description |
|---|---|---|
| Average Phantom Limb Pain | Days 1, 7, 14, 21 | The average phantom limb pain experienced over the previous 3 days evaluated with the 0-10 Numeric Rating Scale with 0=no pain and 10=worst imaginable pain |
| Worst Phantom Limb Pain | Days 1, 7, 14, 21, 28 | The worst phantom limb pain experienced over the previous 3 days evaluated with the 0-10 Numeric Rating Scale with 0=no pain and 10=worst imaginable pain |
| Least Phantom Limb Pain | Days 1, 7, 14, 21, 28. | The least phantom limb pain experienced over the previous 3 days evaluated with the 0-10 Numeric Rating Scale with 0=no pain and 10=worst imaginable pain |
| Current Phantom Limb Pain | Days 1, 7, 14, 21, 28. | The current phantom limb pain at the time of the data collection phone call evaluated with the 0-10 Numeric Rating Scale with 0=no pain and 10=worst imaginable pain |
| Average Residual Limb Pain | Days 1, 7, 14, 21, 28 | The average residual limb pain experienced over the previous 3 days evaluated with the 0-10 Numeric Rating Scale with 0=no pain and 10=worst imaginable pain |
| Worst Residual Limb Pain | Days 1, 7, 14, 21, 28. | The worst residual limb pain experienced over the previous 3 days evaluated with the 0-10 Numeric Rating Scale with 0=no pain and 10=worst imaginable pain |
| Change in Physical and Emotional Functioning at 6 and 12 Months Compared With Baseline (as Measured With the Brief Pain Inventory Interference Domain). | 6 and 12 months following initiation of the initial intervention | The Brief Pain Inventory (interference sub scale) is an instrument that measures the interference with physical and emotional functioning using a 0-10 scale (0 = no interference; 10 = complete interference). The seven interference questions involve general activity, mood, walking ability, normal work activities (both inside and outside of the home), relationships, sleep, and enjoyment of life. The seven functioning questions can be added to produce an interference subscale (0-70). The use of both single items (e.g., mood) and the composite scores is supported. The reported data is the reported interference sub scale at 6 and 12 months compared with baseline. |
| Current Residual Limb Pain | Days 1, 7, 14, 21, 28. | The current residual limb pain at the time of the data collection phone call evaluated with the 0-10 Numeric Rating Scale with 0=no pain and 10=worst imaginable pain |
| Change in Average Phantom Limb Pain at 6 and 12 Months From the Baseline Measurement (as Measured With the 0-10 Numeric Rating Scale) | 6 and 12 months following baseline (the day of the initiation of the initial intervention) | The average phantom limb pain experienced over the previous 3 days evaluated with the 0-10 Numeric Rating Scale with 0=no pain and 10=worst imaginable pain. The data presented is the change in the average phantom limb pain at 6 and 12 months from the baseline measurement. |
| Change in Worst Phantom Limb Pain at 6 and 12 Months From the Baseline Measurement (as Measured With the 0-10 Numeric Rating Scale) | 6 and 12 months following baseline (the day of the initiation of the initial intervention) | The worst phantom limb pain experienced over the previous 3 days evaluated with the 0-10 Numeric Rating Scale with 0=no pain and 10=worst imaginable pain. The data presented is the change in the worst phantom limb pain at 6 and 12 months from the baseline measurement. |
| Change in Average Residual Limb Pain at 6 and 12 Months From the Baseline Measurement (as Measured With the 0-10 Numeric Rating Scale) | 6 and 12 months following baseline (the day of the initiation of the initial intervention) | The average residual limb pain experienced over the previous 3 days evaluated with the 0-10 Numeric Rating Scale with 0=no pain and 10=worst imaginable pain. The data presented is the change in the average residual limb pain at 6 and 12 months from the baseline measurement. |
| Change in Worst Residual Limb Pain at 6 and 12 Months From the Baseline Measurement (as Measured With the 0-10 Numeric Rating Scale) | 6 and 12 months following baseline (the day of the initiation of the initial intervention) | The worst residual limb pain experienced over the previous 3 days evaluated with the 0-10 Numeric Rating Scale with 0=no pain and 10=worst imaginable pain. The data presented is the change in the worst residual limb pain at 6 and 12 months from the baseline measurement. |
| Least Residual Limb Pain | Days 1, 7, 14, 21, 28 | The least residual limb pain experienced over the previous 3 days evaluated with the 0-10 Numeric Rating Scale with 0=no pain and 10=worst imaginable pain |
| Change in Depression 6 and 12 Months Compared With Baseline (as Measured With the Beck Depression Inventory). | 6 and 12 months following initiation of the initial intervention | The Beck Depression Inventory is a 21-item instrument that measures characteristic symptoms and signs of depression, requires only a 5th grade comprehension level to adequately understand the questions, and demonstrates a high internal consistency (0.73-0.92, mean of 0.86), reliability and validity. Each of the 21 factors is rated on a 0-3 scale, and then summed to produce the total score of 0-63. Mild, moderate, and severe depression is defined with scores of 10-18, 19-29, and 30-63, respectively. The data presented are the Beck Depression Inventory at 6 and 12 months compared with baseline. |
| Perception of Well-being (as Measured With the Patient Global Impression of Change Scale). | 6 and 12 months following initiation of intervention | The Patient Global Impression of Change Scale is a 7-point ordinal scale requiring the subject to rate the current severity of their global situation as it relates to phantom limb pain (as defined by each individual) compared to their baseline. This scale has the words very much worse to the left by the number one, and very much improved to the right, adjacent to the number seven. The words no change are in the middle of the scale above the number four. The Patient Global Impression of Change Scale has been validated in over ten prospective trials, including studies specifically involving peripheral neuropathy. |
| Masking Assessment | 4 weeks following the initial intervention | Subjects were asked which study fluid they believed they were receiving during the initial infusion: The possible responses were: ☐Definitely active ☐Probably active ☐Does not know ☐ Probably saline ☐ Definitely saline |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Ropivacaine 0.5% Electronic, programmable, portable infusion pumps will be used to administer perineural study solution at fixed rates for over 6 days. Subjects will receive a total of 1,100 mL of study fluid from either one (upper extremity) or two (lower extremity) pump and external reservoir combinations. The continuous basal infusion rate will be determined by catheter location: femoral 2.5 mL/h; popliteal-sciatic 5 mL/h; and infraclavicular 7.5 mL/h (37.5 mg/h for both upper and lower extremity subjects). No patient-controlled bolus dose will be included. Subjects assigned this treatment for their initial infusion will have the option of returning 4-16 weeks later for a second infusion of the alternate treatment: normal saline.
Perineural infusion \[continuous peripheral nerve block(s)\]: Electronic, programmable, portable infusion pumps will be used to administer perineural study solution at fixed rates for over 6 days. Subjects will receive a total of 1,100 mL of study fluid from either one (upper extremity) or two (lower extremity) pump and external reservoir combinations. The continuous basal infusion rate will be determined by catheter location: femoral 2.5 mL/h; popliteal-sciatic 5 mL/h; and infraclavicular 7.5 mL/h (37.5 mg/h for both upper and lower extremity subjects). No patient-controlled bolus dose will be included. Subjects will have the option of returning 4-16 weeks later for a second infusion of the alternate treatment solution. | 71 |
| Normal Saline (Salt Water) Infusion Electronic, programmable, portable infusion pumps will be used to administer perineural study solution at fixed rates for over 6 days. Subjects will receive a total of 1,100 mL of normal saline placebo fluid from either one (upper extremity) or two (lower extremity) pump and external reservoir combinations. The continuous basal infusion rate will be determined by catheter location: femoral 2.5 mL/h; popliteal-sciatic 5 mL/h; and infraclavicular 7.5 mL/h (37.5 mg/h for both upper and lower extremity subjects). No patient-controlled bolus dose will be included. Subjects assigned this treatment for their initial infusion will have the option of returning 4-16 weeks later for a second infusion of the alternate treatment: ropivacaine 0.5%.
Perineural infusion \[continuous peripheral nerve block(s)\]: Electronic, programmable, portable infusion pumps will be used to administer perineural study solution at fixed rates for over 6 days. Subjects will receive a total of 1,100 mL of study fluid from either one (upper extremity) or two (lower extremity) pump and external reservoir combinations. The continuous basal infusion rate will be determined by catheter location: femoral 2.5 mL/h; popliteal-sciatic 5 mL/h; and infraclavicular 7.5 mL/h (37.5 mg/h for both upper and lower extremity subjects). No patient-controlled bolus dose will be included. Subjects will have the option of returning 4-16 weeks later for a second infusion of the alternate treatment solution. | 73 |
| Total | 144 |
Baseline characteristics
| Characteristic | Normal Saline (Salt Water) Infusion | Total | Ropivacaine 0.5% |
|---|---|---|---|
| Age, Categorical <=18 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical >=65 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical Between 18 and 65 years | 73 Participants | 144 Participants | 71 Participants |
| Amputation Information Additional limb amputation(s) | 11 Participants | 23 Participants | 12 Participants |
| Amputation Information Current prosthesis use | 60 Participants | 110 Participants | 50 Participants |
| Amputation Information Current residual limb pain | 48 Participants | 88 Participants | 40 Participants |
| Amputation Information History of residual limb pain | 57 Participants | 107 Participants | 50 Participants |
| Amputation Information Lower extremity above knee | 24 Participants | 52 Participants | 28 Participants |
| Amputation Information Lower extremity below knee | 39 Participants | 69 Participants | 30 Participants |
| Amputation Information Right (vs. left) side | 37 Participants | 69 Participants | 32 Participants |
| Amputation Information Surgical amputation due to cancer | 5 Participants | 10 Participants | 5 Participants |
| Amputation Information Surgical amputation due to infection | 32 Participants | 59 Participants | 27 Participants |
| Amputation Information Surgical amputation due to other cause | 6 Participants | 10 Participants | 4 Participants |
| Amputation Information Surgical amputation due to trauma | 6 Participants | 13 Participants | 7 Participants |
| Amputation Information Surgical amputation due to vascular deficiency | 8 Participants | 16 Participants | 8 Participants |
| Amputation Information Traumatic amputation | 16 Participants | 36 Participants | 20 Participants |
| Amputation Information Upper extremity above elbow | 8 Participants | 19 Participants | 11 Participants |
| Amputation Information Upper extremity below elbow | 2 Participants | 4 Participants | 2 Participants |
| Beck Depression Inventory Mild depression | 14 Participants | 30 Participants | 16 Participants |
| Beck Depression Inventory Minimal depression | 30 Participants | 55 Participants | 25 Participants |
| Beck Depression Inventory Moderate depression | 20 Participants | 44 Participants | 24 Participants |
| Beck Depression Inventory Severe depression | 9 Participants | 15 Participants | 6 Participants |
| Body mass index | 27 kg/m^2 | 27 kg/m^2 | 27 kg/m^2 |
| Depression as measured with the Beck's Depression Inventory | 14 units on a scale | 14 units on a scale | 15 units on a scale |
| Marital status Currently married | 26 Participants | 63 Participants | 37 Participants |
| Marital status Others (separated and widowed) | 10 Participants | 13 Participants | 3 Participants |
| Marital status Single (or divorced) | 37 Participants | 68 Participants | 31 Participants |
| Military Status Active Duty | 0 Participants | 1 Participants | 1 Participants |
| Military Status Civilian (never in military) | 61 Participants | 117 Participants | 56 Participants |
| Military Status Veteran | 12 Participants | 26 Participants | 14 Participants |
| Pain immediately before and after initial local anesthetic bolus measured on the 0-10 NRS Phantom pain 20 minutes after bolus | 0 units on a scale | 0 units on a scale | 0 units on a scale |
| Pain immediately before and after initial local anesthetic bolus measured on the 0-10 NRS Phantom pain immediately before bolus | 5 units on a scale | 5 units on a scale | 5 units on a scale |
| Pain immediately before and after initial local anesthetic bolus measured on the 0-10 NRS Residual limb pain 20 minutes after bolus | 0 units on a scale | 0 units on a scale | 0 units on a scale |
| Pain immediately before and after initial local anesthetic bolus measured on the 0-10 NRS Residual limb pain immediately before bolus | 3 units on a scale | 2 units on a scale | 1 units on a scale |
| Pain Interference components ( Brief Pain Inventory) Enjoyment of life | 6.0 units on a scale | 6 units on a scale | 6.0 units on a scale |
| Pain Interference components ( Brief Pain Inventory) General activity | 5.0 units on a scale | 5 units on a scale | 6.0 units on a scale |
| Pain Interference components ( Brief Pain Inventory) Mood | 6.0 units on a scale | 6 units on a scale | 6.0 units on a scale |
| Pain Interference components ( Brief Pain Inventory) Normal work | 5.0 units on a scale | 5 units on a scale | 6.0 units on a scale |
| Pain Interference components ( Brief Pain Inventory) Relations with other people | 4.0 units on a scale | 4 units on a scale | 4.0 units on a scale |
| Pain Interference components ( Brief Pain Inventory) Sleep | 7.0 units on a scale | 7 units on a scale | 8.0 units on a scale |
| Pain Interference components ( Brief Pain Inventory) Walking ability | 5.0 units on a scale | 5 units on a scale | 5.0 units on a scale |
| Phantom Pain previous 3 days as measured on the 0-10 NRS Average | 5.0 units on a scale | 5.0 units on a scale | 5.0 units on a scale |
| Phantom Pain previous 3 days as measured on the 0-10 NRS Current | 5.0 units on a scale | 5.0 units on a scale | 5.0 units on a scale |
| Phantom Pain previous 3 days as measured on the 0-10 NRS Least | 3.0 units on a scale | 2.0 units on a scale | 2.0 units on a scale |
| Phantom Pain previous 3 days as measured on the 0-10 NRS Worst | 8.0 units on a scale | 8.0 units on a scale | 8.0 units on a scale |
| Phantom pain relief from medication (%) 0-25% | 22 Participants | 48 Participants | 26 Participants |
| Phantom pain relief from medication (%) 26-50% | 18 Participants | 39 Participants | 21 Participants |
| Phantom pain relief from medication (%) 51-75% | 13 Participants | 18 Participants | 5 Participants |
| Phantom pain relief from medication (%) 76-100% | 4 Participants | 12 Participants | 8 Participants |
| Phantom pain relief from medication (%) Did not use any medication or pain treatment | 16 Participants | 27 Participants | 11 Participants |
| Race and Ethnicity Not Collected | — | 0 Participants | — |
| Region of Enrollment United States | 73 participants | 144 participants | 71 participants |
| Residual limb pain previous 3 days ( Numeric Rating Scale) Average | 4.0 units on a scale | 3 units on a scale | 3 units on a scale |
| Residual limb pain previous 3 days ( Numeric Rating Scale) Current | 3.0 units on a scale | 2.0 units on a scale | 1.0 units on a scale |
| Residual limb pain previous 3 days ( Numeric Rating Scale) Least | 2 units on a scale | 1 units on a scale | 0 units on a scale |
| Residual limb pain previous 3 days ( Numeric Rating Scale) Worst | 6.0 units on a scale | 5 units on a scale | 5 units on a scale |
| Residual pain relief from medication (%) 0-25% | 19 Participants | 42 Participants | 23 Participants |
| Residual pain relief from medication (%) 26-50% | 16 Participants | 26 Participants | 10 Participants |
| Residual pain relief from medication (%) 51-75% | 9 Participants | 14 Participants | 5 Participants |
| Residual pain relief from medication (%) 76-100% | 3 Participants | 11 Participants | 8 Participants |
| Residual pain relief from medication (%) Did not use any medication or pain treatment | 26 Participants | 51 Participants | 25 Participants |
| Sex: Female, Male Female | 30 Participants | 51 Participants | 21 Participants |
| Sex: Female, Male Male | 43 Participants | 93 Participants | 50 Participants |
| Years of education | 13 years | 13 years | 14 years |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 111 | 0 / 98 |
| other Total, other adverse events | 4 / 111 | 4 / 98 |
| serious Total, serious adverse events | 0 / 111 | 1 / 98 |
Outcome results
Primary
Average Phantom Limb Pain Intensity 4 Weeks Following Initiation of an Ambulatory Continuous Peripheral Nerve Block (as Measured by the Numeric Rating Scale Within the Brief Pain Inventory)
Phantom pain will be assessed using a Numeric Rating Scale (NRS) as part of the Brief Pain Inventory (short form), with the average pain score designated as the primary endpoint. In addition, average and worst residual limb pain NRS will be recorded separately from the phantom pain scores. The NRS is a highly-sensitive measure of pain intensity with numbers ranging from 0 to 10, with zero equivalent to no pain and 10 equivalent to the worst imaginable pain. These data are 4 weeks after the initiation of the FIRST intervention (and not the optional crossover treatment).
Time frame: 4 weeks following the initiation of the initial intervention.
Population: Average Phantom Limb Pain Intensity at 4 weeks following the initiation of the first intervention before participants had the option to crossover to the other intervention
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Ropivacaine 0.5% | Average Phantom Limb Pain Intensity 4 Weeks Following Initiation of an Ambulatory Continuous Peripheral Nerve Block (as Measured by the Numeric Rating Scale Within the Brief Pain Inventory) | 3.0 score on a scale | Standard Deviation 2.9 |
| Normal Saline (Salt Water) Infusion | Average Phantom Limb Pain Intensity 4 Weeks Following Initiation of an Ambulatory Continuous Peripheral Nerve Block (as Measured by the Numeric Rating Scale Within the Brief Pain Inventory) | 4.5 score on a scale | Standard Deviation 2.6 |
Secondary
Depression 4 Weeks Following Initiation of Intervention (as Measured With the Beck Depression Inventory).
The Beck Depression Inventory is a 21-item instrument that measures characteristic symptoms and signs of depression, requires only a 5th grade comprehension level to adequately understand the questions, and demonstrates a high internal consistency (0.73-0.92, mean of 0.86), reliability and validity. Each of the 21 factors is rated on a 0-3 scale, and then summed to produce the total score of 0-63. Mild, moderate, and severe depression is defined with scores of 10-18, 19-29, and 30-63, respectively. This data is 4 weeks following the initiation of the initial intervention, and NOT the optional crossover treatment.
Time frame: 4 weeks following initiation of the initial intervention
Population: Depression(as measured with the Beck Depression Inventory) at 4 weeks following the initiation of the first intervention before participants had the option to crossover to the other intervention.
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| Ropivacaine 0.5% | Depression 4 Weeks Following Initiation of Intervention (as Measured With the Beck Depression Inventory). | 6 score on a scale |
| Normal Saline (Salt Water) Infusion | Depression 4 Weeks Following Initiation of Intervention (as Measured With the Beck Depression Inventory). | 13 score on a scale |
Secondary
Perception of Well-being (as Measured With the Patient Global Impression of Change Scale).
The Patient Global Impression of Change Scale is a 7-point ordinal scale requiring the subject to rate the current severity of their global situation as it relates to phantom limb pain (as defined by each individual) compared to their baseline. This scale has the words very much worse to the left by the number one, and very much improved to the right, adjacent to the number seven. The words no change are in the middle of the scale above the number four. The Patient Global Impression of Change Scale has been validated in over ten prospective trials, including studies specifically involving peripheral neuropathy. These data are from 4 weeks after the initiation of the FIRST intervention (and not the optional crossover treatment).
Time frame: 4 weeks following the initiation of the initial intervention
Population: Perception of well-being(as measured with the Patient Global Impression of Change Scale) at 4 weeks following the initiation of the first intervention before participants had the option to crossover to the other intervention.
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| Ropivacaine 0.5% | Perception of Well-being (as Measured With the Patient Global Impression of Change Scale). | 5.0 score on a scale |
| Normal Saline (Salt Water) Infusion | Perception of Well-being (as Measured With the Patient Global Impression of Change Scale). | 4.0 score on a scale |
Secondary
Physical and Emotional Functioning 4 Weeks Following Initiation of Intervention (as Measured With the Brief Pain Inventory Interference Domain).
The Brief Pain Inventory (interference sub scale) is an instrument that measures the interference with physical and emotional functioning using a 0-10 scale (0 = no interference; 10 = complete interference). The seven interference questions involve general activity, mood, walking ability, normal work activities (both inside and outside of the home), relationships, sleep, and enjoyment of life. The seven functioning questions can be added to produce an interference subscale (0-70). The use of both single items (e.g., mood) and the composite scores is supported. These data are from 4 weeks after the initiation of the FIRST intervention (and not the optional crossover treatment).
Time frame: 4 weeks following initiation of the initial intervention
Population: Physical and emotional functioning ( as measured with the Brief Pain Inventory Interference Domain) at 4 weeks following the initiation of the first intervention before participants had the option to crossover to the other intervention.
| Arm | Measure | Group | Value (MEDIAN) |
|---|---|---|---|
| Ropivacaine 0.5% | Physical and Emotional Functioning 4 Weeks Following Initiation of Intervention (as Measured With the Brief Pain Inventory Interference Domain). | Total of 7 components | 11 score on a scale |
| Ropivacaine 0.5% | Physical and Emotional Functioning 4 Weeks Following Initiation of Intervention (as Measured With the Brief Pain Inventory Interference Domain). | General activity | 1.0 score on a scale |
| Ropivacaine 0.5% | Physical and Emotional Functioning 4 Weeks Following Initiation of Intervention (as Measured With the Brief Pain Inventory Interference Domain). | Mood | 0 score on a scale |
| Ropivacaine 0.5% | Physical and Emotional Functioning 4 Weeks Following Initiation of Intervention (as Measured With the Brief Pain Inventory Interference Domain). | Walking ability | 0 score on a scale |
| Ropivacaine 0.5% | Physical and Emotional Functioning 4 Weeks Following Initiation of Intervention (as Measured With the Brief Pain Inventory Interference Domain). | Normal Work | 0 score on a scale |
| Ropivacaine 0.5% | Physical and Emotional Functioning 4 Weeks Following Initiation of Intervention (as Measured With the Brief Pain Inventory Interference Domain). | Relations with others | 0 score on a scale |
| Ropivacaine 0.5% | Physical and Emotional Functioning 4 Weeks Following Initiation of Intervention (as Measured With the Brief Pain Inventory Interference Domain). | Sleep | 2.5 score on a scale |
| Ropivacaine 0.5% | Physical and Emotional Functioning 4 Weeks Following Initiation of Intervention (as Measured With the Brief Pain Inventory Interference Domain). | Enjoyment of life | 1.0 score on a scale |
| Normal Saline (Salt Water) Infusion | Physical and Emotional Functioning 4 Weeks Following Initiation of Intervention (as Measured With the Brief Pain Inventory Interference Domain). | Enjoyment of life | 4.0 score on a scale |
| Normal Saline (Salt Water) Infusion | Physical and Emotional Functioning 4 Weeks Following Initiation of Intervention (as Measured With the Brief Pain Inventory Interference Domain). | Total of 7 components | 28 score on a scale |
| Normal Saline (Salt Water) Infusion | Physical and Emotional Functioning 4 Weeks Following Initiation of Intervention (as Measured With the Brief Pain Inventory Interference Domain). | Normal Work | 3.0 score on a scale |
| Normal Saline (Salt Water) Infusion | Physical and Emotional Functioning 4 Weeks Following Initiation of Intervention (as Measured With the Brief Pain Inventory Interference Domain). | General activity | 5.0 score on a scale |
| Normal Saline (Salt Water) Infusion | Physical and Emotional Functioning 4 Weeks Following Initiation of Intervention (as Measured With the Brief Pain Inventory Interference Domain). | Sleep | 5.5 score on a scale |
| Normal Saline (Salt Water) Infusion | Physical and Emotional Functioning 4 Weeks Following Initiation of Intervention (as Measured With the Brief Pain Inventory Interference Domain). | Mood | 5.0 score on a scale |
| Normal Saline (Salt Water) Infusion | Physical and Emotional Functioning 4 Weeks Following Initiation of Intervention (as Measured With the Brief Pain Inventory Interference Domain). | Relations with others | 2.5 score on a scale |
| Normal Saline (Salt Water) Infusion | Physical and Emotional Functioning 4 Weeks Following Initiation of Intervention (as Measured With the Brief Pain Inventory Interference Domain). | Walking ability | 3.0 score on a scale |
Other Pre-specified
Average Phantom Limb Pain
The average phantom limb pain experienced over the previous 3 days evaluated with the 0-10 Numeric Rating Scale with 0=no pain and 10=worst imaginable pain
Time frame: Days 1, 7, 14, 21
Population: Days 1, 7, 14, 21 following the initiation of the first intervention.
| Arm | Measure | Group | Value (MEDIAN) |
|---|---|---|---|
| Ropivacaine 0.5% | Average Phantom Limb Pain | Day 7 | 2.0 score on a scale |
| Ropivacaine 0.5% | Average Phantom Limb Pain | Day 1 | 0 score on a scale |
| Ropivacaine 0.5% | Average Phantom Limb Pain | Day 21 | 3.0 score on a scale |
| Ropivacaine 0.5% | Average Phantom Limb Pain | Day 14 | 3.0 score on a scale |
| Normal Saline (Salt Water) Infusion | Average Phantom Limb Pain | Day 21 | 4.0 score on a scale |
| Normal Saline (Salt Water) Infusion | Average Phantom Limb Pain | Day 1 | 3.3 score on a scale |
| Normal Saline (Salt Water) Infusion | Average Phantom Limb Pain | Day 14 | 4.5 score on a scale |
| Normal Saline (Salt Water) Infusion | Average Phantom Limb Pain | Day 7 | 4.0 score on a scale |
Other Pre-specified
Average Residual Limb Pain
The average residual limb pain experienced over the previous 3 days evaluated with the 0-10 Numeric Rating Scale with 0=no pain and 10=worst imaginable pain
Time frame: Days 1, 7, 14, 21, 28
Population: Days 1, 7, 14, 21 and 28 following the initiation of the first intervention
| Arm | Measure | Group | Value (MEDIAN) |
|---|---|---|---|
| Ropivacaine 0.5% | Average Residual Limb Pain | Day 7 | 0 score on a scale |
| Ropivacaine 0.5% | Average Residual Limb Pain | Day 21 | 0 score on a scale |
| Ropivacaine 0.5% | Average Residual Limb Pain | Day 14 | 0 score on a scale |
| Ropivacaine 0.5% | Average Residual Limb Pain | Day 28 | 0 score on a scale |
| Ropivacaine 0.5% | Average Residual Limb Pain | Day 1 | 0 score on a scale |
| Normal Saline (Salt Water) Infusion | Average Residual Limb Pain | Day 28 | 3.0 score on a scale |
| Normal Saline (Salt Water) Infusion | Average Residual Limb Pain | Day 1 | 0 score on a scale |
| Normal Saline (Salt Water) Infusion | Average Residual Limb Pain | Day 7 | 1.0 score on a scale |
| Normal Saline (Salt Water) Infusion | Average Residual Limb Pain | Day 14 | 1.5 score on a scale |
| Normal Saline (Salt Water) Infusion | Average Residual Limb Pain | Day 21 | 1.0 score on a scale |
Other Pre-specified
Change in Average Phantom Limb Pain at 6 and 12 Months From the Baseline Measurement (as Measured With the 0-10 Numeric Rating Scale)
The average phantom limb pain experienced over the previous 3 days evaluated with the 0-10 Numeric Rating Scale with 0=no pain and 10=worst imaginable pain. The data presented is the change in the average phantom limb pain at 6 and 12 months from the baseline measurement.
Time frame: 6 and 12 months following baseline (the day of the initiation of the initial intervention)
Population: All subjects received the initial intervention. However, only a subset of each group chose to participate in the optional crossover treatment that occurred 1-4 months following the initiation of the initial treatment infusion. For those who did participate in the optional crossover treatment, they received the alternative treatment as their initial treatment (e.g., subjects who initially received placebo saline subsequently received Ropivacaine 0.5%, and vice versa).
| Arm | Measure | Group | Value (MEDIAN) |
|---|---|---|---|
| Ropivacaine 0.5% | Change in Average Phantom Limb Pain at 6 and 12 Months From the Baseline Measurement (as Measured With the 0-10 Numeric Rating Scale) | 6 month | -3.0 score on a scale |
| Ropivacaine 0.5% | Change in Average Phantom Limb Pain at 6 and 12 Months From the Baseline Measurement (as Measured With the 0-10 Numeric Rating Scale) | 12 month | -2.5 score on a scale |
| Normal Saline (Salt Water) Infusion | Change in Average Phantom Limb Pain at 6 and 12 Months From the Baseline Measurement (as Measured With the 0-10 Numeric Rating Scale) | 12 month | -2.0 score on a scale |
| Normal Saline (Salt Water) Infusion | Change in Average Phantom Limb Pain at 6 and 12 Months From the Baseline Measurement (as Measured With the 0-10 Numeric Rating Scale) | 6 month | -1.5 score on a scale |
| Ropivacaine 0.5% Followed by Placebo Infusion | Change in Average Phantom Limb Pain at 6 and 12 Months From the Baseline Measurement (as Measured With the 0-10 Numeric Rating Scale) | 6 month | 0 score on a scale |
| Ropivacaine 0.5% Followed by Placebo Infusion | Change in Average Phantom Limb Pain at 6 and 12 Months From the Baseline Measurement (as Measured With the 0-10 Numeric Rating Scale) | 12 month | -1.0 score on a scale |
| Placebo Followed by Ropivacaine 0.5% Infusion | Change in Average Phantom Limb Pain at 6 and 12 Months From the Baseline Measurement (as Measured With the 0-10 Numeric Rating Scale) | 6 month | -1.5 score on a scale |
| Placebo Followed by Ropivacaine 0.5% Infusion | Change in Average Phantom Limb Pain at 6 and 12 Months From the Baseline Measurement (as Measured With the 0-10 Numeric Rating Scale) | 12 month | -1.0 score on a scale |
Other Pre-specified
Change in Average Residual Limb Pain at 6 and 12 Months From the Baseline Measurement (as Measured With the 0-10 Numeric Rating Scale)
The average residual limb pain experienced over the previous 3 days evaluated with the 0-10 Numeric Rating Scale with 0=no pain and 10=worst imaginable pain. The data presented is the change in the average residual limb pain at 6 and 12 months from the baseline measurement.
Time frame: 6 and 12 months following baseline (the day of the initiation of the initial intervention)
Population: All subjects received the initial intervention. However, only a subset of each group chose to participate in the optional crossover treatment that occurred 1-4 months following the initiation of the initial treatment infusion. For those who did participate in the optional crossover treatment, they received the alternative treatment as their initial treatment (e.g., subjects who initially received placebo saline subsequently received Ropivacaine 0.5%, and vice versa).
| Arm | Measure | Group | Value (MEDIAN) |
|---|---|---|---|
| Ropivacaine 0.5% | Change in Average Residual Limb Pain at 6 and 12 Months From the Baseline Measurement (as Measured With the 0-10 Numeric Rating Scale) | 6 months | -1.0 score on a scale |
| Ropivacaine 0.5% | Change in Average Residual Limb Pain at 6 and 12 Months From the Baseline Measurement (as Measured With the 0-10 Numeric Rating Scale) | 12 months | -2.0 score on a scale |
| Normal Saline (Salt Water) Infusion | Change in Average Residual Limb Pain at 6 and 12 Months From the Baseline Measurement (as Measured With the 0-10 Numeric Rating Scale) | 12 months | 0 score on a scale |
| Normal Saline (Salt Water) Infusion | Change in Average Residual Limb Pain at 6 and 12 Months From the Baseline Measurement (as Measured With the 0-10 Numeric Rating Scale) | 6 months | 0 score on a scale |
| Ropivacaine 0.5% Followed by Placebo Infusion | Change in Average Residual Limb Pain at 6 and 12 Months From the Baseline Measurement (as Measured With the 0-10 Numeric Rating Scale) | 6 months | 0 score on a scale |
| Ropivacaine 0.5% Followed by Placebo Infusion | Change in Average Residual Limb Pain at 6 and 12 Months From the Baseline Measurement (as Measured With the 0-10 Numeric Rating Scale) | 12 months | 0 score on a scale |
| Placebo Followed by Ropivacaine 0.5% Infusion | Change in Average Residual Limb Pain at 6 and 12 Months From the Baseline Measurement (as Measured With the 0-10 Numeric Rating Scale) | 6 months | -1.0 score on a scale |
| Placebo Followed by Ropivacaine 0.5% Infusion | Change in Average Residual Limb Pain at 6 and 12 Months From the Baseline Measurement (as Measured With the 0-10 Numeric Rating Scale) | 12 months | -1.0 score on a scale |
Other Pre-specified
Change in Depression 6 and 12 Months Compared With Baseline (as Measured With the Beck Depression Inventory).
The Beck Depression Inventory is a 21-item instrument that measures characteristic symptoms and signs of depression, requires only a 5th grade comprehension level to adequately understand the questions, and demonstrates a high internal consistency (0.73-0.92, mean of 0.86), reliability and validity. Each of the 21 factors is rated on a 0-3 scale, and then summed to produce the total score of 0-63. Mild, moderate, and severe depression is defined with scores of 10-18, 19-29, and 30-63, respectively. The data presented are the Beck Depression Inventory at 6 and 12 months compared with baseline.
Time frame: 6 and 12 months following initiation of the initial intervention
Population: All subjects received the initial intervention. However, only a subset of each group chose to participate in the optional crossover treatment that occurred 1-4 months following the initiation of the initial treatment infusion. For those who did participate in the optional crossover treatment, they received the alternative treatment as their initial treatment (e.g., subjects who initially received placebo saline subsequently received Ropivacaine 0.5%, and vice versa).
| Arm | Measure | Group | Value (MEDIAN) |
|---|---|---|---|
| Ropivacaine 0.5% | Change in Depression 6 and 12 Months Compared With Baseline (as Measured With the Beck Depression Inventory). | Month 6 | -3.0 units on a scale |
| Ropivacaine 0.5% | Change in Depression 6 and 12 Months Compared With Baseline (as Measured With the Beck Depression Inventory). | Month 12 | -4.0 units on a scale |
| Normal Saline (Salt Water) Infusion | Change in Depression 6 and 12 Months Compared With Baseline (as Measured With the Beck Depression Inventory). | Month 12 | -2.0 units on a scale |
| Normal Saline (Salt Water) Infusion | Change in Depression 6 and 12 Months Compared With Baseline (as Measured With the Beck Depression Inventory). | Month 6 | -2.0 units on a scale |
| Ropivacaine 0.5% Followed by Placebo Infusion | Change in Depression 6 and 12 Months Compared With Baseline (as Measured With the Beck Depression Inventory). | Month 6 | -1.5 units on a scale |
| Ropivacaine 0.5% Followed by Placebo Infusion | Change in Depression 6 and 12 Months Compared With Baseline (as Measured With the Beck Depression Inventory). | Month 12 | -1.5 units on a scale |
| Placebo Followed by Ropivacaine 0.5% Infusion | Change in Depression 6 and 12 Months Compared With Baseline (as Measured With the Beck Depression Inventory). | Month 6 | -4.0 units on a scale |
| Placebo Followed by Ropivacaine 0.5% Infusion | Change in Depression 6 and 12 Months Compared With Baseline (as Measured With the Beck Depression Inventory). | Month 12 | -4.0 units on a scale |
Other Pre-specified
Change in Physical and Emotional Functioning at 6 and 12 Months Compared With Baseline (as Measured With the Brief Pain Inventory Interference Domain).
The Brief Pain Inventory (interference sub scale) is an instrument that measures the interference with physical and emotional functioning using a 0-10 scale (0 = no interference; 10 = complete interference). The seven interference questions involve general activity, mood, walking ability, normal work activities (both inside and outside of the home), relationships, sleep, and enjoyment of life. The seven functioning questions can be added to produce an interference subscale (0-70). The use of both single items (e.g., mood) and the composite scores is supported. The reported data is the reported interference sub scale at 6 and 12 months compared with baseline.
Time frame: 6 and 12 months following initiation of the initial intervention
Population: All subjects received the initial intervention. However, only a subset of each group chose to participate in the optional crossover treatment that occurred 1-4 months following the initiation of the initial treatment infusion. For those who did participate in the optional crossover treatment, they received the alternative treatment as their initial treatment (e.g., subjects who initially received placebo saline subsequently received Ropivacaine 0.5%, and vice versa).
| Arm | Measure | Group | Value (MEDIAN) |
|---|---|---|---|
| Ropivacaine 0.5% | Change in Physical and Emotional Functioning at 6 and 12 Months Compared With Baseline (as Measured With the Brief Pain Inventory Interference Domain). | Normal work (6months following initiation of intervention) | -2.5 score on a scale |
| Ropivacaine 0.5% | Change in Physical and Emotional Functioning at 6 and 12 Months Compared With Baseline (as Measured With the Brief Pain Inventory Interference Domain). | Enjoyment of life (12 months following initiation of intervention) | -1.0 score on a scale |
| Ropivacaine 0.5% | Change in Physical and Emotional Functioning at 6 and 12 Months Compared With Baseline (as Measured With the Brief Pain Inventory Interference Domain). | Enjoyment of life (6months following initiation of intervention) | -2.0 score on a scale |
| Ropivacaine 0.5% | Change in Physical and Emotional Functioning at 6 and 12 Months Compared With Baseline (as Measured With the Brief Pain Inventory Interference Domain). | Sleep (6months following initiation of intervention) | -3.8 score on a scale |
| Ropivacaine 0.5% | Change in Physical and Emotional Functioning at 6 and 12 Months Compared With Baseline (as Measured With the Brief Pain Inventory Interference Domain). | Relations with others (6months following initiation of intervention) | -1.0 score on a scale |
| Ropivacaine 0.5% | Change in Physical and Emotional Functioning at 6 and 12 Months Compared With Baseline (as Measured With the Brief Pain Inventory Interference Domain). | Relations with others (12 months following initiation of intervention) | -1.0 score on a scale |
| Ropivacaine 0.5% | Change in Physical and Emotional Functioning at 6 and 12 Months Compared With Baseline (as Measured With the Brief Pain Inventory Interference Domain). | Walking ability (6months following initiation of intervention) | 0 score on a scale |
| Ropivacaine 0.5% | Change in Physical and Emotional Functioning at 6 and 12 Months Compared With Baseline (as Measured With the Brief Pain Inventory Interference Domain). | Mood (6months following initiation of intervention) | -1.0 score on a scale |
| Ropivacaine 0.5% | Change in Physical and Emotional Functioning at 6 and 12 Months Compared With Baseline (as Measured With the Brief Pain Inventory Interference Domain). | Sleep (12 months following initiation of intervention) | -1.0 score on a scale |
| Ropivacaine 0.5% | Change in Physical and Emotional Functioning at 6 and 12 Months Compared With Baseline (as Measured With the Brief Pain Inventory Interference Domain). | Normal work (12 months following initiation of intervention) | -1.0 score on a scale |
| Ropivacaine 0.5% | Change in Physical and Emotional Functioning at 6 and 12 Months Compared With Baseline (as Measured With the Brief Pain Inventory Interference Domain). | Walking ability (12 months following initiation of intervention) | -1.0 score on a scale |
| Ropivacaine 0.5% | Change in Physical and Emotional Functioning at 6 and 12 Months Compared With Baseline (as Measured With the Brief Pain Inventory Interference Domain). | General activity (6months following initiation of intervention) | -1.5 score on a scale |
| Ropivacaine 0.5% | Change in Physical and Emotional Functioning at 6 and 12 Months Compared With Baseline (as Measured With the Brief Pain Inventory Interference Domain). | Mood (12 months following initiation of intervention) | 0 score on a scale |
| Ropivacaine 0.5% | Change in Physical and Emotional Functioning at 6 and 12 Months Compared With Baseline (as Measured With the Brief Pain Inventory Interference Domain). | General activity (12 months following initiation of intervention) | -1.0 score on a scale |
| Normal Saline (Salt Water) Infusion | Change in Physical and Emotional Functioning at 6 and 12 Months Compared With Baseline (as Measured With the Brief Pain Inventory Interference Domain). | Normal work (12 months following initiation of intervention) | -1.0 score on a scale |
| Normal Saline (Salt Water) Infusion | Change in Physical and Emotional Functioning at 6 and 12 Months Compared With Baseline (as Measured With the Brief Pain Inventory Interference Domain). | General activity (6months following initiation of intervention) | -2.0 score on a scale |
| Normal Saline (Salt Water) Infusion | Change in Physical and Emotional Functioning at 6 and 12 Months Compared With Baseline (as Measured With the Brief Pain Inventory Interference Domain). | Mood (6months following initiation of intervention) | -1.0 score on a scale |
| Normal Saline (Salt Water) Infusion | Change in Physical and Emotional Functioning at 6 and 12 Months Compared With Baseline (as Measured With the Brief Pain Inventory Interference Domain). | Walking ability (6months following initiation of intervention) | -1.0 score on a scale |
| Normal Saline (Salt Water) Infusion | Change in Physical and Emotional Functioning at 6 and 12 Months Compared With Baseline (as Measured With the Brief Pain Inventory Interference Domain). | Normal work (6months following initiation of intervention) | -1.0 score on a scale |
| Normal Saline (Salt Water) Infusion | Change in Physical and Emotional Functioning at 6 and 12 Months Compared With Baseline (as Measured With the Brief Pain Inventory Interference Domain). | Relations with others (6months following initiation of intervention) | 0 score on a scale |
| Normal Saline (Salt Water) Infusion | Change in Physical and Emotional Functioning at 6 and 12 Months Compared With Baseline (as Measured With the Brief Pain Inventory Interference Domain). | Sleep (6months following initiation of intervention) | -1.5 score on a scale |
| Normal Saline (Salt Water) Infusion | Change in Physical and Emotional Functioning at 6 and 12 Months Compared With Baseline (as Measured With the Brief Pain Inventory Interference Domain). | Enjoyment of life (6months following initiation of intervention) | -1.0 score on a scale |
| Normal Saline (Salt Water) Infusion | Change in Physical and Emotional Functioning at 6 and 12 Months Compared With Baseline (as Measured With the Brief Pain Inventory Interference Domain). | General activity (12 months following initiation of intervention) | -1.0 score on a scale |
| Normal Saline (Salt Water) Infusion | Change in Physical and Emotional Functioning at 6 and 12 Months Compared With Baseline (as Measured With the Brief Pain Inventory Interference Domain). | Mood (12 months following initiation of intervention) | -1.0 score on a scale |
| Normal Saline (Salt Water) Infusion | Change in Physical and Emotional Functioning at 6 and 12 Months Compared With Baseline (as Measured With the Brief Pain Inventory Interference Domain). | Walking ability (12 months following initiation of intervention) | 0 score on a scale |
| Normal Saline (Salt Water) Infusion | Change in Physical and Emotional Functioning at 6 and 12 Months Compared With Baseline (as Measured With the Brief Pain Inventory Interference Domain). | Relations with others (12 months following initiation of intervention) | 0 score on a scale |
| Normal Saline (Salt Water) Infusion | Change in Physical and Emotional Functioning at 6 and 12 Months Compared With Baseline (as Measured With the Brief Pain Inventory Interference Domain). | Sleep (12 months following initiation of intervention) | 0 score on a scale |
| Normal Saline (Salt Water) Infusion | Change in Physical and Emotional Functioning at 6 and 12 Months Compared With Baseline (as Measured With the Brief Pain Inventory Interference Domain). | Enjoyment of life (12 months following initiation of intervention) | -1.0 score on a scale |
| Ropivacaine 0.5% Followed by Placebo Infusion | Change in Physical and Emotional Functioning at 6 and 12 Months Compared With Baseline (as Measured With the Brief Pain Inventory Interference Domain). | Normal work (12 months following initiation of intervention) | -3.0 score on a scale |
| Ropivacaine 0.5% Followed by Placebo Infusion | Change in Physical and Emotional Functioning at 6 and 12 Months Compared With Baseline (as Measured With the Brief Pain Inventory Interference Domain). | Sleep (12 months following initiation of intervention) | -1.0 score on a scale |
| Ropivacaine 0.5% Followed by Placebo Infusion | Change in Physical and Emotional Functioning at 6 and 12 Months Compared With Baseline (as Measured With the Brief Pain Inventory Interference Domain). | General activity (6months following initiation of intervention) | 0 score on a scale |
| Ropivacaine 0.5% Followed by Placebo Infusion | Change in Physical and Emotional Functioning at 6 and 12 Months Compared With Baseline (as Measured With the Brief Pain Inventory Interference Domain). | Walking ability (6months following initiation of intervention) | 0 score on a scale |
| Ropivacaine 0.5% Followed by Placebo Infusion | Change in Physical and Emotional Functioning at 6 and 12 Months Compared With Baseline (as Measured With the Brief Pain Inventory Interference Domain). | Relations with others (12 months following initiation of intervention) | -1.0 score on a scale |
| Ropivacaine 0.5% Followed by Placebo Infusion | Change in Physical and Emotional Functioning at 6 and 12 Months Compared With Baseline (as Measured With the Brief Pain Inventory Interference Domain). | Sleep (6months following initiation of intervention) | 0 score on a scale |
| Ropivacaine 0.5% Followed by Placebo Infusion | Change in Physical and Emotional Functioning at 6 and 12 Months Compared With Baseline (as Measured With the Brief Pain Inventory Interference Domain). | Relations with others (6months following initiation of intervention) | 0 score on a scale |
| Ropivacaine 0.5% Followed by Placebo Infusion | Change in Physical and Emotional Functioning at 6 and 12 Months Compared With Baseline (as Measured With the Brief Pain Inventory Interference Domain). | Walking ability (12 months following initiation of intervention) | 0 score on a scale |
| Ropivacaine 0.5% Followed by Placebo Infusion | Change in Physical and Emotional Functioning at 6 and 12 Months Compared With Baseline (as Measured With the Brief Pain Inventory Interference Domain). | General activity (12 months following initiation of intervention) | -1.0 score on a scale |
| Ropivacaine 0.5% Followed by Placebo Infusion | Change in Physical and Emotional Functioning at 6 and 12 Months Compared With Baseline (as Measured With the Brief Pain Inventory Interference Domain). | Mood (6months following initiation of intervention) | 0 score on a scale |
| Ropivacaine 0.5% Followed by Placebo Infusion | Change in Physical and Emotional Functioning at 6 and 12 Months Compared With Baseline (as Measured With the Brief Pain Inventory Interference Domain). | Normal work (6months following initiation of intervention) | 0 score on a scale |
| Ropivacaine 0.5% Followed by Placebo Infusion | Change in Physical and Emotional Functioning at 6 and 12 Months Compared With Baseline (as Measured With the Brief Pain Inventory Interference Domain). | Enjoyment of life (12 months following initiation of intervention) | 0 score on a scale |
| Ropivacaine 0.5% Followed by Placebo Infusion | Change in Physical and Emotional Functioning at 6 and 12 Months Compared With Baseline (as Measured With the Brief Pain Inventory Interference Domain). | Enjoyment of life (6months following initiation of intervention) | 0 score on a scale |
| Ropivacaine 0.5% Followed by Placebo Infusion | Change in Physical and Emotional Functioning at 6 and 12 Months Compared With Baseline (as Measured With the Brief Pain Inventory Interference Domain). | Mood (12 months following initiation of intervention) | -1.0 score on a scale |
| Placebo Followed by Ropivacaine 0.5% Infusion | Change in Physical and Emotional Functioning at 6 and 12 Months Compared With Baseline (as Measured With the Brief Pain Inventory Interference Domain). | Enjoyment of life (6months following initiation of intervention) | -2.0 score on a scale |
| Placebo Followed by Ropivacaine 0.5% Infusion | Change in Physical and Emotional Functioning at 6 and 12 Months Compared With Baseline (as Measured With the Brief Pain Inventory Interference Domain). | General activity (12 months following initiation of intervention) | -1.0 score on a scale |
| Placebo Followed by Ropivacaine 0.5% Infusion | Change in Physical and Emotional Functioning at 6 and 12 Months Compared With Baseline (as Measured With the Brief Pain Inventory Interference Domain). | Sleep (12 months following initiation of intervention) | -0.5 score on a scale |
| Placebo Followed by Ropivacaine 0.5% Infusion | Change in Physical and Emotional Functioning at 6 and 12 Months Compared With Baseline (as Measured With the Brief Pain Inventory Interference Domain). | Mood (12 months following initiation of intervention) | -0.5 score on a scale |
| Placebo Followed by Ropivacaine 0.5% Infusion | Change in Physical and Emotional Functioning at 6 and 12 Months Compared With Baseline (as Measured With the Brief Pain Inventory Interference Domain). | Mood (6months following initiation of intervention) | -1.0 score on a scale |
| Placebo Followed by Ropivacaine 0.5% Infusion | Change in Physical and Emotional Functioning at 6 and 12 Months Compared With Baseline (as Measured With the Brief Pain Inventory Interference Domain). | Walking ability (12 months following initiation of intervention) | 0 score on a scale |
| Placebo Followed by Ropivacaine 0.5% Infusion | Change in Physical and Emotional Functioning at 6 and 12 Months Compared With Baseline (as Measured With the Brief Pain Inventory Interference Domain). | General activity (6months following initiation of intervention) | -2.0 score on a scale |
| Placebo Followed by Ropivacaine 0.5% Infusion | Change in Physical and Emotional Functioning at 6 and 12 Months Compared With Baseline (as Measured With the Brief Pain Inventory Interference Domain). | Normal work (12 months following initiation of intervention) | -1.5 score on a scale |
| Placebo Followed by Ropivacaine 0.5% Infusion | Change in Physical and Emotional Functioning at 6 and 12 Months Compared With Baseline (as Measured With the Brief Pain Inventory Interference Domain). | Enjoyment of life (12 months following initiation of intervention) | 0 score on a scale |
| Placebo Followed by Ropivacaine 0.5% Infusion | Change in Physical and Emotional Functioning at 6 and 12 Months Compared With Baseline (as Measured With the Brief Pain Inventory Interference Domain). | Relations with others (12 months following initiation of intervention) | -0.5 score on a scale |
| Placebo Followed by Ropivacaine 0.5% Infusion | Change in Physical and Emotional Functioning at 6 and 12 Months Compared With Baseline (as Measured With the Brief Pain Inventory Interference Domain). | Relations with others (6months following initiation of intervention) | 0 score on a scale |
| Placebo Followed by Ropivacaine 0.5% Infusion | Change in Physical and Emotional Functioning at 6 and 12 Months Compared With Baseline (as Measured With the Brief Pain Inventory Interference Domain). | Normal work (6months following initiation of intervention) | -1.0 score on a scale |
| Placebo Followed by Ropivacaine 0.5% Infusion | Change in Physical and Emotional Functioning at 6 and 12 Months Compared With Baseline (as Measured With the Brief Pain Inventory Interference Domain). | Sleep (6months following initiation of intervention) | 0 score on a scale |
| Placebo Followed by Ropivacaine 0.5% Infusion | Change in Physical and Emotional Functioning at 6 and 12 Months Compared With Baseline (as Measured With the Brief Pain Inventory Interference Domain). | Walking ability (6months following initiation of intervention) | -1.0 score on a scale |
Other Pre-specified
Change in Worst Phantom Limb Pain at 6 and 12 Months From the Baseline Measurement (as Measured With the 0-10 Numeric Rating Scale)
The worst phantom limb pain experienced over the previous 3 days evaluated with the 0-10 Numeric Rating Scale with 0=no pain and 10=worst imaginable pain. The data presented is the change in the worst phantom limb pain at 6 and 12 months from the baseline measurement.
Time frame: 6 and 12 months following baseline (the day of the initiation of the initial intervention)
Population: All subjects received the initial intervention. However, only a subset of each group chose to participate in the optional crossover treatment that occurred 1-4 months following the initiation of the initial treatment infusion. For those who did participate in the optional crossover treatment, they received the alternative treatment as their initial treatment (e.g., subjects who initially received placebo saline subsequently received Ropivacaine 0.5%, and vice versa).
| Arm | Measure | Group | Value (MEDIAN) |
|---|---|---|---|
| Ropivacaine 0.5% | Change in Worst Phantom Limb Pain at 6 and 12 Months From the Baseline Measurement (as Measured With the 0-10 Numeric Rating Scale) | 6 months | -2.0 score on a scale |
| Ropivacaine 0.5% | Change in Worst Phantom Limb Pain at 6 and 12 Months From the Baseline Measurement (as Measured With the 0-10 Numeric Rating Scale) | 12 months | -2.0 score on a scale |
| Normal Saline (Salt Water) Infusion | Change in Worst Phantom Limb Pain at 6 and 12 Months From the Baseline Measurement (as Measured With the 0-10 Numeric Rating Scale) | 12 months | -1.0 score on a scale |
| Normal Saline (Salt Water) Infusion | Change in Worst Phantom Limb Pain at 6 and 12 Months From the Baseline Measurement (as Measured With the 0-10 Numeric Rating Scale) | 6 months | -2.5 score on a scale |
| Ropivacaine 0.5% Followed by Placebo Infusion | Change in Worst Phantom Limb Pain at 6 and 12 Months From the Baseline Measurement (as Measured With the 0-10 Numeric Rating Scale) | 6 months | 0 score on a scale |
| Ropivacaine 0.5% Followed by Placebo Infusion | Change in Worst Phantom Limb Pain at 6 and 12 Months From the Baseline Measurement (as Measured With the 0-10 Numeric Rating Scale) | 12 months | 0 score on a scale |
| Placebo Followed by Ropivacaine 0.5% Infusion | Change in Worst Phantom Limb Pain at 6 and 12 Months From the Baseline Measurement (as Measured With the 0-10 Numeric Rating Scale) | 6 months | -1.0 score on a scale |
| Placebo Followed by Ropivacaine 0.5% Infusion | Change in Worst Phantom Limb Pain at 6 and 12 Months From the Baseline Measurement (as Measured With the 0-10 Numeric Rating Scale) | 12 months | -1.5 score on a scale |
Other Pre-specified
Change in Worst Residual Limb Pain at 6 and 12 Months From the Baseline Measurement (as Measured With the 0-10 Numeric Rating Scale)
The worst residual limb pain experienced over the previous 3 days evaluated with the 0-10 Numeric Rating Scale with 0=no pain and 10=worst imaginable pain. The data presented is the change in the worst residual limb pain at 6 and 12 months from the baseline measurement.
Time frame: 6 and 12 months following baseline (the day of the initiation of the initial intervention)
Population: All subjects received the initial intervention. However, only a subset of each group chose to participate in the optional crossover treatment that occurred 1-4 months following the initiation of the initial treatment infusion. For those who did participate in the optional crossover treatment, they received the alternative treatment as their initial treatment (e.g., subjects who initially received placebo saline subsequently received Ropivacaine 0.5%, and vice versa).
| Arm | Measure | Group | Value (MEDIAN) |
|---|---|---|---|
| Ropivacaine 0.5% | Change in Worst Residual Limb Pain at 6 and 12 Months From the Baseline Measurement (as Measured With the 0-10 Numeric Rating Scale) | 6 months | -1.0 score on a scale |
| Ropivacaine 0.5% | Change in Worst Residual Limb Pain at 6 and 12 Months From the Baseline Measurement (as Measured With the 0-10 Numeric Rating Scale) | 12 months | -3.0 score on a scale |
| Normal Saline (Salt Water) Infusion | Change in Worst Residual Limb Pain at 6 and 12 Months From the Baseline Measurement (as Measured With the 0-10 Numeric Rating Scale) | 12 months | 0 score on a scale |
| Normal Saline (Salt Water) Infusion | Change in Worst Residual Limb Pain at 6 and 12 Months From the Baseline Measurement (as Measured With the 0-10 Numeric Rating Scale) | 6 months | 0 score on a scale |
| Ropivacaine 0.5% Followed by Placebo Infusion | Change in Worst Residual Limb Pain at 6 and 12 Months From the Baseline Measurement (as Measured With the 0-10 Numeric Rating Scale) | 6 months | 0 score on a scale |
| Ropivacaine 0.5% Followed by Placebo Infusion | Change in Worst Residual Limb Pain at 6 and 12 Months From the Baseline Measurement (as Measured With the 0-10 Numeric Rating Scale) | 12 months | 0 score on a scale |
| Placebo Followed by Ropivacaine 0.5% Infusion | Change in Worst Residual Limb Pain at 6 and 12 Months From the Baseline Measurement (as Measured With the 0-10 Numeric Rating Scale) | 6 months | 0 score on a scale |
| Placebo Followed by Ropivacaine 0.5% Infusion | Change in Worst Residual Limb Pain at 6 and 12 Months From the Baseline Measurement (as Measured With the 0-10 Numeric Rating Scale) | 12 months | 0 score on a scale |
Other Pre-specified
Current Phantom Limb Pain
The current phantom limb pain at the time of the data collection phone call evaluated with the 0-10 Numeric Rating Scale with 0=no pain and 10=worst imaginable pain
Time frame: Days 1, 7, 14, 21, 28.
Population: Days 1, 7, 14, 21 and 28 following the initiation of the first intervention
| Arm | Measure | Group | Value (MEDIAN) |
|---|---|---|---|
| Ropivacaine 0.5% | Current Phantom Limb Pain | Day 7 | 0 score on a scale |
| Ropivacaine 0.5% | Current Phantom Limb Pain | Day 21 | 1.00 score on a scale |
| Ropivacaine 0.5% | Current Phantom Limb Pain | Day 14 | 2.0 score on a scale |
| Ropivacaine 0.5% | Current Phantom Limb Pain | Day 28 | 0.50 score on a scale |
| Ropivacaine 0.5% | Current Phantom Limb Pain | Day 1 | 0 score on a scale |
| Normal Saline (Salt Water) Infusion | Current Phantom Limb Pain | Day 28 | 4.0 score on a scale |
| Normal Saline (Salt Water) Infusion | Current Phantom Limb Pain | Day 1 | 3.0 score on a scale |
| Normal Saline (Salt Water) Infusion | Current Phantom Limb Pain | Day 7 | 3.0 score on a scale |
| Normal Saline (Salt Water) Infusion | Current Phantom Limb Pain | Day 14 | 4.0 score on a scale |
| Normal Saline (Salt Water) Infusion | Current Phantom Limb Pain | Day 21 | 4.0 score on a scale |
Other Pre-specified
Current Residual Limb Pain
The current residual limb pain at the time of the data collection phone call evaluated with the 0-10 Numeric Rating Scale with 0=no pain and 10=worst imaginable pain
Time frame: Days 1, 7, 14, 21, 28.
Population: Days 1, 7, 14, 21 and 28 following the initiation of the first intervention
| Arm | Measure | Group | Value (MEDIAN) |
|---|---|---|---|
| Ropivacaine 0.5% | Current Residual Limb Pain | Day 21 | 0 score on a scale |
| Ropivacaine 0.5% | Current Residual Limb Pain | Day 28 | 0 score on a scale |
| Ropivacaine 0.5% | Current Residual Limb Pain | Day 1 | 0 score on a scale |
| Ropivacaine 0.5% | Current Residual Limb Pain | Day 7 | 0 score on a scale |
| Ropivacaine 0.5% | Current Residual Limb Pain | Day 14 | 0 score on a scale |
| Normal Saline (Salt Water) Infusion | Current Residual Limb Pain | Day 14 | 0 score on a scale |
| Normal Saline (Salt Water) Infusion | Current Residual Limb Pain | Day 7 | 0 score on a scale |
| Normal Saline (Salt Water) Infusion | Current Residual Limb Pain | Day 28 | 1.0 score on a scale |
| Normal Saline (Salt Water) Infusion | Current Residual Limb Pain | Day 21 | 0.5 score on a scale |
| Normal Saline (Salt Water) Infusion | Current Residual Limb Pain | Day 1 | 0 score on a scale |
Other Pre-specified
Least Phantom Limb Pain
The least phantom limb pain experienced over the previous 3 days evaluated with the 0-10 Numeric Rating Scale with 0=no pain and 10=worst imaginable pain
Time frame: Days 1, 7, 14, 21, 28.
Population: Days 1, 7, 14, 21 and 28 following the initiation of the first intervention
| Arm | Measure | Group | Value (MEDIAN) |
|---|---|---|---|
| Ropivacaine 0.5% | Least Phantom Limb Pain | Day 7 | 0 score on a scale |
| Ropivacaine 0.5% | Least Phantom Limb Pain | Day 21 | 1.0 score on a scale |
| Ropivacaine 0.5% | Least Phantom Limb Pain | Day 14 | 1.0 score on a scale |
| Ropivacaine 0.5% | Least Phantom Limb Pain | Day 28 | 0 score on a scale |
| Ropivacaine 0.5% | Least Phantom Limb Pain | Day 1 | 0 score on a scale |
| Normal Saline (Salt Water) Infusion | Least Phantom Limb Pain | Day 28 | 2.0 score on a scale |
| Normal Saline (Salt Water) Infusion | Least Phantom Limb Pain | Day 1 | 0 score on a scale |
| Normal Saline (Salt Water) Infusion | Least Phantom Limb Pain | Day 7 | 1.3 score on a scale |
| Normal Saline (Salt Water) Infusion | Least Phantom Limb Pain | Day 14 | 1.0 score on a scale |
| Normal Saline (Salt Water) Infusion | Least Phantom Limb Pain | Day 21 | 1.5 score on a scale |
Other Pre-specified
Least Residual Limb Pain
The least residual limb pain experienced over the previous 3 days evaluated with the 0-10 Numeric Rating Scale with 0=no pain and 10=worst imaginable pain
Time frame: Days 1, 7, 14, 21, 28
Population: Days 1, 7, 14, 21 and 28 following the initiation of the first intervention
| Arm | Measure | Group | Value (MEDIAN) |
|---|---|---|---|
| Ropivacaine 0.5% | Least Residual Limb Pain | Day 7 | 0 score on a scale |
| Ropivacaine 0.5% | Least Residual Limb Pain | Day 21 | 0 score on a scale |
| Ropivacaine 0.5% | Least Residual Limb Pain | Day 14 | 0 score on a scale |
| Ropivacaine 0.5% | Least Residual Limb Pain | Day 28 | 0 score on a scale |
| Ropivacaine 0.5% | Least Residual Limb Pain | Day 1 | 0 score on a scale |
| Normal Saline (Salt Water) Infusion | Least Residual Limb Pain | Day 28 | 3.0 score on a scale |
| Normal Saline (Salt Water) Infusion | Least Residual Limb Pain | Day 1 | 0 score on a scale |
| Normal Saline (Salt Water) Infusion | Least Residual Limb Pain | Day 7 | 1.0 score on a scale |
| Normal Saline (Salt Water) Infusion | Least Residual Limb Pain | Day 14 | 1.5 score on a scale |
| Normal Saline (Salt Water) Infusion | Least Residual Limb Pain | Day 21 | 1.0 score on a scale |
Other Pre-specified
Masking Assessment
Subjects were asked which study fluid they believed they were receiving during the initial infusion: The possible responses were: ☐Definitely active ☐Probably active ☐Does not know ☐ Probably saline ☐ Definitely saline
Time frame: 4 weeks following the initial intervention
Population: Data analysed 28 days following the initial intervention and before the crossover treatment. So its analysed based on participants included in each arm group for the initial treatment. Not applicable for crossover treatment option.
| Arm | Measure | Group | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|
| Ropivacaine 0.5% | Masking Assessment | Probably Active | 17 Participants |
| Ropivacaine 0.5% | Masking Assessment | Definitely Saline | 3 Participants |
| Ropivacaine 0.5% | Masking Assessment | Does not know | 18 Participants |
| Ropivacaine 0.5% | Masking Assessment | Definitely Active | 10 Participants |
| Ropivacaine 0.5% | Masking Assessment | Missing | 7 Participants |
| Ropivacaine 0.5% | Masking Assessment | Probably Saline | 16 Participants |
| Normal Saline (Salt Water) Infusion | Masking Assessment | Missing | 8 Participants |
| Normal Saline (Salt Water) Infusion | Masking Assessment | Probably Saline | 33 Participants |
| Normal Saline (Salt Water) Infusion | Masking Assessment | Definitely Active | 2 Participants |
| Normal Saline (Salt Water) Infusion | Masking Assessment | Probably Active | 8 Participants |
| Normal Saline (Salt Water) Infusion | Masking Assessment | Definitely Saline | 4 Participants |
| Normal Saline (Salt Water) Infusion | Masking Assessment | Does not know | 18 Participants |
Other Pre-specified
Perception of Well-being (as Measured With the Patient Global Impression of Change Scale).
The Patient Global Impression of Change Scale is a 7-point ordinal scale requiring the subject to rate the current severity of their global situation as it relates to phantom limb pain (as defined by each individual) compared to their baseline. This scale has the words very much worse to the left by the number one, and very much improved to the right, adjacent to the number seven. The words no change are in the middle of the scale above the number four. The Patient Global Impression of Change Scale has been validated in over ten prospective trials, including studies specifically involving peripheral neuropathy.
Time frame: 6 and 12 months following initiation of intervention
| Arm | Measure | Group | Value (MEDIAN) |
|---|---|---|---|
| Ropivacaine 0.5% | Perception of Well-being (as Measured With the Patient Global Impression of Change Scale). | 12 months following initiation of intervention | 6.0 units on a scale |
| Ropivacaine 0.5% | Perception of Well-being (as Measured With the Patient Global Impression of Change Scale). | 6 months following initiation of intervention | 7.0 units on a scale |
| Normal Saline (Salt Water) Infusion | Perception of Well-being (as Measured With the Patient Global Impression of Change Scale). | 6 months following initiation of intervention | 5.0 units on a scale |
| Normal Saline (Salt Water) Infusion | Perception of Well-being (as Measured With the Patient Global Impression of Change Scale). | 12 months following initiation of intervention | 5.0 units on a scale |
| Ropivacaine 0.5% Followed by Placebo Infusion | Perception of Well-being (as Measured With the Patient Global Impression of Change Scale). | 12 months following initiation of intervention | 4.0 units on a scale |
| Ropivacaine 0.5% Followed by Placebo Infusion | Perception of Well-being (as Measured With the Patient Global Impression of Change Scale). | 6 months following initiation of intervention | 4.0 units on a scale |
| Placebo Followed by Ropivacaine 0.5% Infusion | Perception of Well-being (as Measured With the Patient Global Impression of Change Scale). | 12 months following initiation of intervention | 4.0 units on a scale |
| Placebo Followed by Ropivacaine 0.5% Infusion | Perception of Well-being (as Measured With the Patient Global Impression of Change Scale). | 6 months following initiation of intervention | 4.0 units on a scale |
Other Pre-specified
Worst Phantom Limb Pain
The worst phantom limb pain experienced over the previous 3 days evaluated with the 0-10 Numeric Rating Scale with 0=no pain and 10=worst imaginable pain
Time frame: Days 1, 7, 14, 21, 28
Population: Days 1, 7, 14, 21 and 28 following the initiation of the first intervention
| Arm | Measure | Group | Value (MEDIAN) |
|---|---|---|---|
| Ropivacaine 0.5% | Worst Phantom Limb Pain | Day 21 | 5.0 score on a scale |
| Ropivacaine 0.5% | Worst Phantom Limb Pain | Day 1 | 0.50 score on a scale |
| Ropivacaine 0.5% | Worst Phantom Limb Pain | Day 7 | 4.0 score on a scale |
| Ropivacaine 0.5% | Worst Phantom Limb Pain | Day 14 | 6.8 score on a scale |
| Ropivacaine 0.5% | Worst Phantom Limb Pain | Day 28 | 5.0 score on a scale |
| Normal Saline (Salt Water) Infusion | Worst Phantom Limb Pain | Day 28 | 8.0 score on a scale |
| Normal Saline (Salt Water) Infusion | Worst Phantom Limb Pain | Day 14 | 7.0 score on a scale |
| Normal Saline (Salt Water) Infusion | Worst Phantom Limb Pain | Day 1 | 5.0 score on a scale |
| Normal Saline (Salt Water) Infusion | Worst Phantom Limb Pain | Day 21 | 7.0 score on a scale |
| Normal Saline (Salt Water) Infusion | Worst Phantom Limb Pain | Day 7 | 7.0 score on a scale |
Other Pre-specified
Worst Residual Limb Pain
The worst residual limb pain experienced over the previous 3 days evaluated with the 0-10 Numeric Rating Scale with 0=no pain and 10=worst imaginable pain
Time frame: Days 1, 7, 14, 21, 28.
Population: Days 1, 7, 14, 21 and 28 following the initiation of the first intervention
| Arm | Measure | Group | Value (MEDIAN) |
|---|---|---|---|
| Ropivacaine 0.5% | Worst Residual Limb Pain | Day 21 | 0 score on a scale |
| Ropivacaine 0.5% | Worst Residual Limb Pain | Day 28 | 0 score on a scale |
| Ropivacaine 0.5% | Worst Residual Limb Pain | Day 1 | 0 score on a scale |
| Ropivacaine 0.5% | Worst Residual Limb Pain | Day 7 | 0 score on a scale |
| Ropivacaine 0.5% | Worst Residual Limb Pain | Day 14 | 0 score on a scale |
| Normal Saline (Salt Water) Infusion | Worst Residual Limb Pain | Day 14 | 4.0 score on a scale |
| Normal Saline (Salt Water) Infusion | Worst Residual Limb Pain | Day 21 | 4.0 score on a scale |
| Normal Saline (Salt Water) Infusion | Worst Residual Limb Pain | Day 7 | 3.0 score on a scale |
| Normal Saline (Salt Water) Infusion | Worst Residual Limb Pain | Day 28 | 6.0 score on a scale |
| Normal Saline (Salt Water) Infusion | Worst Residual Limb Pain | Day 1 | 0.50 score on a scale |