Test of a Non-invasive PVI Measure with a Fiber-optic Pressure Monitoring Device in Head Injured Patients

Abstract

Measurement of brain compliance has proven a valuable tool for understanding the biomechanics of intracranial pressure. More recently, we have shown that the pressure volume index, assessed within 24 h of injury, is a prognostic value in identifying those patients who subsequently develop raised intracranial pressure (Maset et al. 1987). However, methods for determining the pressure volume status in head injured patients, must be obtained via analysis of the pressure response to bolus injections or the removal of CSF through ventricular catheter systems. There are practical restrictions on the number of times PVI can be measured using these volume manipulation techniques. The concept, introduced by Bray at the Glasgow meeting, of extracting PVI measurements from analysis of the pulse pressure centroid, represents a less invasive technique and has the potential for providing PVI data continuously (Bray et al. 1986).