MODELING CHANGES OF THE CEREBRAL VASCULATURE INDUCED BY VARIATIONS OF [PCO.sub.2].
MODELING CHANGES OF THE CEREBRAL VASCULATURE INDUCED BY VARIATIONS OF [PCO.sub.2]. Richard Pasley, Chunzhi Wang, Charles W. Leffler, and Michael L. Daley, The University of Memphis, Memphis, Tennessee (RP, CW, MLD), and The University of Tennessee, Memphis, Memphis, Tennessee (CWL). Clinical recordings of intracranial pressure (ICP) and arterial blood pressure (ABP) of patients with brain injury vary. For one pathophysiologic state, the pressure recordings are dissimilar, while in another they are similar. The purpose of this study was to develop a model that describes the changes observed in coefficients of correlation readings. The model assumes compression of the cerebral capillary bed by transmission of changes of intrathoracic pressure associated with ventilation. During normal vascular tone, the ICP and ABP recordings are dissimilar and the compression effect is minimal. The compression effect progressively reduces as tone is lost and the recordings become markedly similar. The model is designed to gene rate a theoretical ICP wave for different amounts of [PCO.sub.2] using a given APF waveform. Coefficients of correlation are then calculated to demonstrate the model performs as predicted.