Analysis of Cerebrovascular Autoregulation Reactivity Index Electronic Monitoring Methods

摘要

Pathophysiological processes in the injured human brain proceed quickly and are very risky for human life. Human brain cerebrovascular autoregulation is a vital protective function of the cerebral vasculature. Human brain is at risk of secondary injury especially when this function fails. Innovative methods and technologies for continuous monitoring of injured brain have been designed in order to minimize the disability or mortality rate of such patients. Continuous monitoring of the absolute values and time dependences of intracranial pressure (ICP), arterial blood pressure (ABP) and cerebral perfusion pressure (CPP), also continuous monitoring of brain compliance and cerebrovascular autoregulation (CA) are very important for treating brain injuries [1]. The concept of preventing secondary insults after traumatic brain injury (TBI) involves maintaining of sufficient oxygen delivery to the intracranial neural tissues and preventing tissues from cerebral hypoxia. This implies that cerebral blood flow (CBF), arterial oxygen saturation and hemoglobin concentration in a specific patient must be adequate. Impairment of CBF autoregulation has a strong impact for TBI patients outcome. It is not enough to monitor ICP, ABP and CPP in order to optimize the TBI treatment decisions. So, it is essential to know the real-time status of CBF autoregulation [2-18].Consensus was already achieved [11] that the CBF autoregulatory state of TBI patients has to be monitored and the individualized treatment strategy should be re-valuated regularly over the time course of CBF autoregulation status. The Brain Trauma Foundation (USA) also sees the CBF autoregulation monitoring as an only tool for fine-tune individual patient CPP optimization and treatment optimization goals [10]. Electronic CBF autoregulation monitoring methods have to be developed for that purpose.