Abstract
Recently, impaired cerebral blood flow autoregulation has been reported to be associated with poor outcomes for patients with severe subarachnoid hemorrhage (SAH) and traumatic brain injury (TBI). The Pressure Reactivity Index (PRx) derived from the Pearson correlation coefficient between intracranial pressure (ICP) and mean arterial blood pressure (MABP) has been reported as a useful indicator of impaired cerebrovascular autoregulation at the acute stage of severe SAH and TBI. We investigated whether the indicator monitored during the acute stage strongly correlated with the outcomes for patients with poor-grade SAH and severe TBI. The results of our study revealed that values of the PRx at the acute stage increased in the groups of patients with the development of cerebral vasospasm after SAH. In the group of patients who developed delayed cerebral infarction following cerebral vasospasm, the increase in the mean values of the PRx were significant compared to those for the group of patients without cerebral vasospasm. The PRx values of patients with poor outcomes after severe TBI were significantly higher than those of patients with favorable outcomes. We report the usefulness of PRx monitoring at the acute stage of severe brain damage.
