DYNAMICS OF INTRACRANIAL PRESSURE AND VENOUS DRAINAGE

描述：（申请人摘要）在常规神经外科手术期间 闭合性颅脑损伤患者的床旁重症监护 动脉和颅内压信号的生理监测 已经完成了 这项工作的长期目标是发展：1） 对产生节奏的原因的进一步理解 颅内压信号基线的变化;和2） 技术，以提取额外的病理生理信息， 用于患者重症监护的颅内压信号 头部闭合性损伤 这项研究的结果可能会产生方法 这可以增强床旁生理监测的使用， 包括检测脑血流调节的丧失， 导致改进管理战略， 患者头部严重受伤。 根据我们的初步临床和实验室结果， 已经提出了一种假设：在完整的脑血管张力期间， 颅内压基线的低频变化是 由脑静脉血容量的相应变化引起 通过在正压吸入期间限制静脉流动。 期间 血管张力丧失，无限制的静脉流动发生在积极的 压力吸入 为了检验他的假设，将使用以下两个具体目标： 脑血流量的生理记录和测定 从实验室模型中获得。 首先，使用颅骨 脑静脉血容量的窗口比例变化 测量前和后壁的以下时变参数， 后顶叶静脉在一个网站附近，他们的连接到 矢状窦：1）视频测微技术测量直径; 2)用激光多普勒测速仪测量流量; 3）用红外线测量容积 法 其次，将建立脑血流的血液动力学模型。 开发 实验测量值与预测值的比较 为了评估其有效性，将制作模型。

DESCRIPTION: (Applicant's Abstract) During the routine neurosurgical intensive care of the patient with closed head-injury, bedside physiologic monitoring of the arterial and intracranial pressure signals is accomplished. The long term goals of this work are to develop: 1) a further understanding of the causal factors which produce rhythmic changes in the baseline of the intracranial pressure signals; and 2) techniques to extract additional pathophysiologic information from the intracranial pressure signal used in the intensive care of the patient with closed head-injury. The results of this study may produce methods which could enhance the use of bedside physiological monitoring to include the detection of loss of regulation of cerebral blood flow and lead to an improvement in the management strategies designed for the patient with severe head-injury. From our preliminary clinical and laboratory findings the following hypothesis has been developed: During intact cerebral vascular tone, the low frequency variation in the baseline of intracranial pressure is produced by a corresponding change of cerebral venous blood volume caused by restricted venous flow during positive pressure inhalation. During loss of vascular tone, unrestricted venous flow occurs during positive pressure inhalation. To test his hypothesis two specific aims will be addressed using physiological recordings and determination of cerebral blood flow obtained from a laboratory model. First, with the use of a cranial window proportional changes of cerebral venous blood volume by measurement of the following time-varying parameters of the anterior and posterior parietal veins at a site near to their connection to the sagittal sinus will be made: 1) diameter by video micrometer technique; 2) flow by laser doppler velocimetery; and 3) volume by infrared technique. Second, a hemodynamic model of cerebral blood flow will be developed. comparison of experimental measures with those predicted by the model will be made in order to evaluate its validity.