Cerebral Autoregulation Monitoring to Reduce Brain Injury from Cardiac Surgery

脑自动调节监测可减少心脏手术造成的脑损伤

• 批准号: 8293199
• 负责人: CHARLES W HOGUE
• 金额: $ 32.3万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-08-01 至 2014-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8293199
• 关键词: Address; Area; Blood; Blood Flow Velocity; Blood Pressure; Blood Vessels; Blood Volume; Blood flow; Brain; Brain Injuries; Cardiac; Cardiac Surgery procedures; Cardiopulmonary Bypass; Caregivers; Caring; Cephalic; Cerebral Emboli; Cerebrovascular Circulation; Cerebrum; Clinical; Cognitive; Complication; Computer software; Confounding Factors (Epidemiology); Coronary Artery Bypass; Data; Diagnosis; Diffusion; Diffusion Magnetic Resonance Imaging; Diffusion weighted imaging; Distal; Early Diagnosis; Effectiveness; Ensure; Frequencies; Gender; Health Care Costs; Health Expenditures; Hemoglobin; Homeostasis; Hospitalization; Image; Impaired cognition; Individual; Injury; Intervention; Lead; Lesion; Linear Regressions; Magnetic Resonance Angiography; Magnetic Resonance Imaging; Measures; Mediating; Metabolic; Methods; Mission; Monitor; National Heart, Lung, and Blood Institute; Near-Infrared Spectroscopy; Neurologic; Neurological outcome; Operative Surgical Procedures; Outcome; Oxygen saturation measurement; Patient Monitoring; Patients; Perfusion; Perioperative; Postoperative Period; Public Health; Quality of life; Randomized; Regional Perfusion; Resistance; Risk; Role; Source; Spectrum Analysis; Stenosis; Stroke; Techniques; Testing; Time; Vascular Diseases; Weight; aged; base; cerebral artery; cerebral hypoperfusion; exhaust; high risk; indexing; middle cerebral artery; mortality; novel; pressure; time use; trend

Brain injury during cardiac surgery results primarily from cerebral embolism and/or reduced cerebral blood flow (CBF). The latter is of particular concern for the growing number of surgical patients who are aged and/or who have cerebral vascular disease. Normally, CBF is physiologically autoregulated (or kept constant) within a range of blood pressures allowing for stable cerebral O2 supply commensurate with metabolic demands. Cerebral autoregulation is impaired in patients undergoing cardiac surgery who have cerebral vascular disease and in many others due to other conditions. This could lead to brain injury since current practices of targeting low mean arterial blood pressure empirically (usually 50-70 mmHg) during cardiopulmonary bypass may expose patients with impaired cerebral autoregulation to cerebral hypoperfusion. The hypothesis of this proposal is that targeting mean arterial pressure during cardiopulmonary bypass to a level above an individual's lower autoregulatory threshold reduces the risk for brain injury in patients undergoing cardiac surgery. Monitoring of cerebral autoregulation will be performed in real time using software that continuously compares the relation between arterial blood pressure and CBF velocity of the middle cerebral artery measured with transcranial Doppler and with cerebral oximetry measured with near infrared spectroscopy. The primary end-point of the study will be a comprehensive composite outcome of clinical stroke, cognitive decline, and/or new ischemic brain lesions detected with diffusion weighted magnetic resonance (MR) imaging. Autoregulation is mediated by reactivity of cerebral resistance vessels. A secondary aim of this proposal is to evaluate whether near infrared reflectance spectroscopy can be used to trend changes in cerebral blood volume and provide a reliable monitor of vascular reactivity (the hemoglobin volume index). Assessments for extra-cranial and intra-cranial arterial stenosis will be performed using MR angiography to control for this potential confounding variable in the analysis. Finally, an additional aim of the study will be to assess whether preoperative transcranial Doppler examination of major cerebral arteries can identify patients who are prone to the composite neurological end-point. Near infrared oximetry is non-invasive, continuous, requires little care- giver intervention and, thus, could be widely used to individualize patient blood pressure management during surgery. Brain injury from cardiac surgery is an important source of operative mortality, prolonged hospitalization, increased health care expenditure, and impaired quality of life. Developing strategies to reduce the burden of this complication has wide public health implications and is within the mission of the NHLBI.

心脏手术中的脑损伤主要由脑栓塞和/或脑血流减少引起 （CBF）.后者尤其令人关注的是，越来越多的老年和/或 患有脑血管疾病。正常情况下，CBF在生理学上是自动调节的（或保持恒定）， 血压范围允许稳定的大脑O2供应与代谢需求相称。 患有脑血管疾病的心脏手术患者的脑自动调节功能受损 在许多其他情况下，由于其他条件。这可能会导致脑损伤，因为目前的做法， 在心肺转流术期间，经验上的低平均动脉血压（通常为50-70 mmHg）可能 使脑自动调节受损的患者暴露于脑灌注不足。这个假设 建议将心肺转流期间的平均动脉压定为高于 个体较低的自动调节阈值降低了心脏病患者脑损伤的风险 手术将使用软件进行真实的脑自动调节监测， 比较动脉血压与大脑中动脉血流速度的关系 用经颅多普勒和用近红外光谱测量的脑血氧测定法测量。的 研究的主要终点是临床中风，认知能力下降， 和/或用扩散加权磁共振（MR）成像检测到的新的缺血性脑损伤。 自身调节是由脑阻力血管的反应性介导的。这项建议的第二个目的是 评估近红外反射光谱法是否可用于脑血中的趋势变化 体积和提供血管反应性的可靠监测（血红蛋白体积指数）。年分摊 将使用MR血管造影术进行颅外和颅内动脉狭窄，以控制这一点 分析中的潜在混杂变量。最后，研究的另一个目的是评估是否 术前经颅多普勒检查主要脑动脉可以识别患者谁是倾向于 复合神经学终点。近红外血氧测定法是非侵入性的，连续的，几乎不需要护理- 给予者干预，因此，可以广泛用于个性化患者的血压管理， 手术心脏手术引起的脑损伤是手术死亡率的重要来源， 住院、医疗保健支出增加和生活质量下降。制定战略以减少 这种并发症的负担具有广泛的公共卫生影响，并且在NHLBI的使命范围内。