Doblar D D
Department of Anesthesiology, University of Alabama at Birmingham 35233- 1924, USA.
J Cardiothorac Vasc Anesth. 1996 Jan;10(1):3-14. doi: 10.1016/s1053-0770(96)80173-x.
With increased attention to the causes and effects of neurologic injury related to cardiopulmonary bypass anesthesia and surgery, multiple modality examination and monitoring of cerebral function and perfusion in the perioperative period may prove to be advantageous. Transcranial Doppler examination and monitoring is inexpensive, noninvasive, safe, provides unique information about the functional status of the intracranial circulation, and complements the duplex Doppler study of the extracranial carotid vessels of the neck for preoperative evaluation of the surgical patient. The transcranial Doppler examination permits quantitation of blood flow velocity of the intracranial vessels, evaluation of autoregulatory capacity and vasomotor reserve, determination of symmetry of flow velocity in the circle of Willis, assessment of collateral circulatory capacity, examination of vessels not accessible to the duplex Doppler and serves as a baseline for intraoperative monitoring and the postoperative examination. Noninvasive, unilateral or bilateral, continuous monitoring of brain blood flow velocity intraoperatively or postoperatively with trending, storage, and correlation with other physiologic variables provides evidence of cerebral perfusion, occurrence and rate of cerebral embolism, and continuous monitoring of therapeutic interventions. A review of the incidence of stroke and neuropsychologic deficit after bypass surgery is focused on parameters amenable to diagnosis using transcranial Doppler. Patient-specific risk factors for neurologic injury derived from previous studies are discussed as well as risk factors that are related to anesthetic and surgical management and equipment. A description of Doppler technology and the correlation of transcranial Doppler findings with angiography and radionucleotide scans establishes the accuracy of the Doppler examination. The preoperative examination, provocative tests of vasomotor reserve, the evaluation of cerebral collateral circulation, and examples of Doppler applications are discussed.
随着对与体外循环麻醉和手术相关的神经损伤的原因及影响的关注度不断提高，围手术期对脑功能和灌注进行多模态检查和监测可能会被证明是有益的。经颅多普勒检查和监测成本低廉、无创、安全，可提供有关颅内循环功能状态的独特信息，并且是对颈部颅外颈动脉进行双功多普勒研究的补充，用于手术患者的术前评估。经颅多普勒检查可对颅内血管的血流速度进行定量分析，评估自动调节能力和血管舒缩储备，确定 Willis 环中血流速度的对称性，评估侧支循环能力，检查双功多普勒无法检测到的血管，并作为术中监测和术后检查的基线。术中或术后通过趋势分析、存储以及与其他生理变量的相关性，对脑血流速度进行无创、单侧或双侧连续监测，可提供脑灌注、脑栓塞的发生及发生率的证据，以及对治疗干预措施的连续监测。对搭桥手术后中风和神经心理缺陷发生率的综述重点关注了可通过经颅多普勒进行诊断的参数。讨论了先前研究得出的患者特异性神经损伤风险因素，以及与麻醉和手术管理及设备相关的风险因素。对多普勒技术的描述以及经颅多普勒检查结果与血管造影和放射性核素扫描的相关性确定了多普勒检查的准确性。还讨论了术前检查、血管舒缩储备激发试验、脑侧支循环评估以及多普勒应用实例。
