Improving Postamputation Functioning by Decreasing Phantom Limb Pain and Opioid Use with Perioperative Continuous Peripheral Nerve Blocks: A Multicenter RCT
Abstract
Rationale: When a limb is amputated, pain perceived in the part of the body that no longer exists often develops. This is called “phantom limb” pain and is different from “residual limb” or “stump” pain, which is pain within the part of the limb that remains intact. Phantom pain often greatly decreases individuals’ mobility and ability to function. Unfortunately, phantom pain goes away in only 16% of afflicted individuals, and there is currently no reliable definitive treatment. Therefore, it is very important to prevent phantom limb pain from developing in the first place. Unfortunately, presently there is no reliable method demonstrated to decrease chronic pain following an amputation. The exact reason that phantom limb pain occurs is unclear, but when a nerve is cut -- as happens with an amputation -- changes occur in the brain and spinal cord that are associated with persistent pain. The negative feedback-loop between the injured limb and the brain can be stopped by putting local anesthetic -- called a “nerve block” -- on the injured nerve, effectively keeping any “bad signals” from reaching the brain. A “continuous peripheral nerve block” (CPNB) is a technique providing pain relief that involves inserting a tiny tube -- smaller than a piece of spaghetti -- through the skin and next to the target nerve. Local anesthetic is then introduced through the tiny tube, which bathes the nerve in the numbing medicine. This provides a multiple-day block that provides opioid-free pain control with no side effects, and may prevent the destructive feedback loop that results in phantom limb pain following an amputation. We have completed a small study suggesting that an intense CPNB begun immediately before and for 5 days following a surgical amputation holds great promise to prevent phantom limb pain, while at the same time decreasing opioid requirements and increasing short- and long-term functioning. We now propose a much larger study at multiple hospitals that will give us a definitive answer as to whether or not this treatment will benefit patients in both the short and long term. Applicability: The proposed study directly addresses the Fiscal Year Peer Reviewed Orthopaedic Research Program topic area “Post-Operative Pain Management” by treating post-operative pain during and following surgical amputation or major residual limb revision with an intense CPNB, independent of opioid administration. The ultimate objective of the proposed clinical trial is to improve post-amputation functioning, primarily by decreasing the incidence and severity of chronic phantom limb pain that has a significant negative effect on post-operative prosthetic use and functional ability/reintegration. Therefore, the proposed clinical trial will validate a strategy “for post-operative pain management following orthopaedic trauma that minimize[s] or eliminate[s] opioid use.” Military Impact: A very large percentage of the 200,000 patients undergoing limb amputation and major residual limb revision in the United States each year is comprised of active duty military personnel and Veterans due to combat-related trauma and peripheral vascular disease. For example, Veterans undergo surgical amputation at a rate 250% higher than the general population: each year over 10% of all male amputees are Veterans (>10,000 individuals). Of all amputees, 35%-98% develop phantom limb pain. Since phantom pain resolves in only 16% of individuals and there is currently no reliable definitive treatment, potentially all future patients undergoing a surgical amputation would benefit if an intense CPNB was found to prevent short- and long-term pain. Chronic pain is one of the greatest limiters of post-amputation mobility and functioning, decreasing the ability to use a prosthesis, ambulate, and generally function -- all considerably decreasing the chance of return to duty or civilian work. Persistent pain also leads to sleep disorders and accompanies lon
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Oct 29, 2018
- Source ID
- W81XWH1710671
Entities
People
- Brian M Ilfeld
Organizations
- United States Army
- University of California, San Diego