The impact of impaired cerebral autoregulation on postoperative delirium

描述(由申请人提供)：术后环境中的精神错乱是常见的，并与显著的发病率、死亡率和费用有关。老年患者术后精神错乱的风险尤其高，随着美国人口老龄化，将有更多的老年患者接受手术。术后精神错乱的长期后遗症包括死亡率增加、认知功能下降、功能结果下降和医院费用增加。虽然许多因素可能导致术后精神错乱，但术中脑血流不足可能是一个重要的可改变的原因。患有高血压和脑血管疾病的老年患者可能需要比预期更高的血压来维持足够的CBF。目前，麻醉师将血压维持在经验值以上，并假定CBF是充足的。然而，目前还没有常规的临床监测来直接测量脑血流，因此老年患者存在脑低灌注率的高风险。最近，已经开发了新的技术来实时评估单个患者的CBF充分性。通过监测处于高RIS的个体患者的术后精神障碍，可以确定脑血流不足与术后精神障碍之间的潜在联系。这项观察性研究将招募100名在约翰·霍普金斯医院接受脊柱手术的70岁以上的患者。每个患者都将接受严格的术前认知测试。术中将实时评估CBF的充分性。术后，将评估精神错乱和长期认知功能障碍的发生率。本项目的具体目标是：1.评估手术中患者血压超出CBF自动调节范围的持续时间是否与术后精神障碍有关。2.探讨脊柱手术后3~6周的认知功能障碍与术后精神障碍的关系。该项目的长期目标是通过监测CBF来减少术后精神障碍的发生率，预测术后精神障碍的发展，并预防因精神错乱可能导致的认知能力下降。如果成功，该项目将确定术后精神错乱的一个重要危险因素，可以在术中进行修改。 公共卫生相关性：术后精神错乱在老年人中很常见，并与显著的死亡率和发病率有关，包括认知能力下降。这个项目将 寻求确定术后精神错乱的潜在可改变的危险因素。如果成功，BOH术后精神错乱及其对老年人的长期后遗症，包括认知能力下降，可以被预防。

DESCRIPTION (provided by applicant): Delirium in the post-operative setting is common and is associated with significant morbidity, mortality, and cost. Elderly patients are at a particulary high risk for postoperative delirium, and as the US population ages, more elderly patients will present for surgery. Long-term sequelae of postoperative delirium include increased mortality, decreased cognitive function, decreased functional outcomes, and increased hospital costs. Although many factors may contribute to post-operative delirium, inadequate intraoperative cerebral blood flow (CBF) may be an important modifiable cause. Elderly patients, with high rates of hypertension and cerebral vascular disease, may require higher than expected blood pressures to maintain adequate CBF. Currently, anesthesiologists maintain blood pressure above empiric targets, with the assumption that CBF is adequate. However, no routine clinical monitor is currently used to directly measure CBF, and so elderly patients are at high risk of cerebral hypoperfusion. Recently, novel technology has been developed to assess the adequacy of CBF in real time, in individual patients. By monitoring individual patients at high ris for postoperative delirium, a potential association could be identified between inadequate CBF and postoperative delirium. This observational study will enroll 100 patients greater than 70 years old undergoing spine surgery at Johns Hopkins Hospital. Each patient will undergo rigorous preoperative cognitive testing. Intraoperatively, the adequacy of CBF will be assessed in real time. Postoperatively, the incidence of delirium and long-term cognitive dysfunction will be evaluated. The specific aims of this project are: 1. To assess whether the duration of time during surgery that a patient's blood pressures is outside the limits of CBF autoregulation is associated with postoperative delirium. 2. To assess whether the development of postoperative delirium is associated with cognitive dysfunction 3 to 6 weeks after spine surgery. The long-term objectives of this project are to reduce the incidence of postoperative delirium through monitoring of CBF, to predict the development of postoperative delirium, and to prevent cognitive decline that may result from delirium. If successful, this project will identify an important risk factor for postoperative delirium, that could be modified intraoperatively. PUBLIC HEALTH RELEVANCE: Postoperative delirium in the elderly is common and is associated with significant mortality and morbidity, including cognitive decline. This project will seek to identify a potentially modifiable risk factor for postoperative delirium. If successful, boh postoperative delirium and its long term sequelae in the elderly, including cognitive decline, could be prevented.