Transcranial Direct Current Stimulation in the Management of Post-operative Pain

描述（由申请人提供）：适当控制急性和慢性疼痛是医疗保健中最重要的领域之一。尽管在过去的20年里，神经科学取得了巨大的进步，但我们仍然大量使用鸦片类麻醉剂，就像内战期间一样。全膝关节置换术（TKA）是最常见的骨科手术之一。虽然膝关节疼痛通常是全膝关节置换术前的主抱怨，但手术本身与持续数天至数周的相当大的术后疼痛有关，适当的术后疼痛控制是决定恢复时间和住院时间的重要因素。治疗术后疼痛的主要方法包括全身性阿片类药物和局部阻滞。尽管有这些策略，患者仍然报告术后疼痛，并且经常

DESCRIPTION (provided by applicant): The proper control of acute and chronic pain is one of the most important areas in health care. Despite the profound advances in neuroscience over the past 20 years, we still largely use opiate narcotics, much as was done in the Civil War. Total knee arthroplasty (TKA) is one of the most common orthopedic procedures performed. While knee pain is often a complaint that precedes TKA, the procedure itself is associated with considerable post-operative pain lasting days to weeks, and adequate postoperative pain control is an important factor in determining recovery time and hospital length of stay. Primary methods used to manage post-operative pain involve systemic opioid drugs, and regional blocks. Despite these strategies, patients still report considerable post-operative pain, and often struggle to complete post-operative physical therapy regimens. Additionally, systemic opioid analgesics have associated side-effects that can lead to post-operative complications including but not limited to mental-clouding, confusion, addiction (in some cases), respiratory depression, interactions with other medications, and fatigue. These are not trivial concerns as the population receiving TKA are more and more likely to be elderly and/or overweight and thus these complications can have serious negative consequences. New analgesic strategies are needed that can be used adjunctively to existing strategies with the potential to reduce reliance on opioid analgesia. Several novel brain stimulation technologies including transcranial direct current stimulation (tDCS) are beginning to demonstrate promise as treatments for a variety of pain conditions. Electricity has no metabolite or other residue, and can be delivered with minimal discomfort and without problems associated with drug-drug interactions. In two preliminary studies, the investigators have found that tDCS can reduce post-operative PCA use by as much as 46% in TKA patients while simultaneously reducing subjective pain ratings. These findings are promising, but this new technology is in its infancy, and a foundation of well-controlled, high-quality clinical trials needs to be established before this field moves forward. The proposed study will be the first randomized, double-blind, sham-controlled clinical trial of the effects of tDCS on subjective pain-ratings, PCA opioid usage, and post- operative complications among patients receiving unilateral TKA surgery. Further, this study will examine the relative efficacy of different analgesic electrode placement strategies compared to sham stimulation as well as examine the effects of pain-targeted tDCS compared to an active-sham strategy wherein real brain stimulation will be delivered, but over areas of the brain that should be unrelated to pain experience (thereby determining whether there is any tDCS targeting specificity). Data from this trial will likely yield information regarding the feasibility and effiacy of tDCS as a post-operative pain-management approach. If the proposed pilot trial suggests significant and meaningful effects of tDCS as an adjunctive post-operative pain management strategy, this could change the way post-operative pain management is approached in the future.