Dose Dependent Effects of tDCS on Post-Operative Pain

描述(由申请人提供)： 急性和慢性疼痛的适当控制是医疗保健中最重要的领域之一。尽管神经科学在过去20年里取得了深刻的进步，但我们仍然在很大程度上使用鸦片类麻醉剂，就像内战中所做的那样。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TKA前的症状，但手术本身与持续数天至数周的相当大的术后疼痛有关，而适当的术后疼痛控制是决定恢复时间、住院时间和长期手术结果的重要因素。用于控制术后疼痛的主要方法主要是全身阿片类药物。尽管有可用的策略，患者仍然报告术后相当大的疼痛，并且经常挣扎于完成术后物理治疗方案。此外，全身性阿片类药物有相关的副作用，可能导致术后并发症，包括但不限于精神模糊、神志不清、上瘾、呼吸抑制、与其他药物的相互作用以及疲劳。这些都不是微不足道的问题，因为接受TKA的人口越来越有可能是老年人和/或超重，因此这些并发症可能会产生严重的负面后果。需要新的止痛策略，这些策略可以作为现有策略的补充，有可能减少对阿片类止痛的依赖。几种新的脑刺激技术，包括经颅直流电刺激(Tdcs)，开始显示出作为各种疼痛状况的治疗方法的前景。电没有代谢物或其他残留物，可以在最小程度上感到不适，也不会出现药物与药物相互作用的问题。在两项初步研究中，研究人员发现，TDC可以将TKA患者术后PCA的使用减少高达46%，同时降低主观疼痛评级。这些发现是有希望的，但这项新技术还处于初级阶段，在这一领域取得进展之前，需要建立一个受控良好的高质量临床试验的基础。这项拟议的研究将是第一次随机、双盲、假对照的临床试验，研究TDC对主观疼痛评分、PCA阿片类药物使用、 以及接受单侧TKA手术的退伍军人的术后并发症。此外，这项研究将检验3种不同的tdcs给药策略与假刺激相比的相对疗效。来自这项试验的数据可能会提供有关tdcs作为术后疼痛管理方法的可行性和有效性的信息。如果拟议的试点试验表明TDC作为术后疼痛管理的辅助策略具有显著和有意义的效果，这可能会改变未来处理术后疼痛管理的方式。

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, hospital length of stay, and long-term surgical outcomes. Primary methods used to manage post-operative pain primarily involve systemic opiates. Despite available strategies, patients still report considerable post-operative pain, and often struggle to complete post-operative physical therapy regimens. Additionally, systemic opiates have associated side-effects that can lead to post-operative complications including but not limited to mental-clouding, confusion, addiction, 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 veterans receiving unilateral TKA surgery. Further, this study will examine the relative efficacy of 3 different tDCS dosing strategies compared to sham stimulation. Data from this trial will likely yield information regarding the feasibility and efficacy 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.