The impact of impaired cerebral autoregulation on postoperative delirium

描述（由申请人提供）：术后谵妄很常见，与显著的发病率、死亡率和成本相关。老年患者术后谵妄的风险特别高，随着美国人口的老龄化，更多的老年患者将接受手术。术后谵妄的长期后遗症包括死亡率增加、认知功能下降、功能结局下降和住院费用增加。虽然许多因素可能导致术后谵妄，术中脑血流量（CBF）不足可能是一个重要的可改变的原因。老年患者高血压和脑血管疾病发生率高，可能需要高于预期的血压来维持足够的CBF。目前，麻醉师保持血压高于经验目标，假设CBF是足够的。然而，目前还没有常规的临床监测仪用于直接测量CBF，因此老年患者脑灌注不足的风险很高。最近，新的技术已经开发出来，以评估充分的CBF在真实的时间，在个别患者。通过监测术后谵妄高风险个体患者，可以确定CBF不足和术后谵妄之间的潜在关联。这项观察性研究将入组100例在约翰霍普金斯医院接受脊柱手术的70岁以上患者。每位患者都将接受严格的术前认知测试。术中将对CBF的充分性进行真实的评估。术后，将评价谵妄和长期认知功能障碍的发生率。该项目的具体目标是：1。评估手术期间患者血压超出CBF自动调节限度的持续时间是否与术后谵妄相关。2.评估术后谵妄的发生是否与脊柱手术后3 - 6周的认知功能障碍有关。该项目的长期目标是通过监测CBF降低术后谵妄的发生率，预测术后谵妄的发展，并预防可能由谵妄导致的认知功能下降。如果成功，该项目将确定术后谵妄的重要风险因素，可以在术中进行修改。

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.