Pulse pressure and mean pressure relationship of intracranial pressure and lumbar cerebrospinal fluid pressure / 生物医学工程学杂志

ABSTRACT

Intracranial pressure fluctuates due to heart beat, respiration, neuro-regulation, etc. Traditional intracranial pressure study focuses on the static pressure and related factors, putting emphasis on mean intracranial pressure, while paying little attention to the pulse components. This study was composed of two parts animal experiment and theoretical analysis. The animal experiment was performed on 14 mongrel dogs, studying the variation of intracranial pressure wave form under different intracranial pressure level. The dogs were installed epidurally with latex sacculus to establish models of increased intracranial pressure. The degree of intracranial pressure and volume could be altered by changing the volume of fluid in the sacculus. During the process, pressure transducers were arranged to monitor and record the variations of the pressure of intracranial ventricle and lumbar subarachnoid cavity. The result demonstrated that, with the continual increase of intracranial pressure, intracranial pulse pressure increased correspondingly, showing a linear relationship with the change of intracranial pressure. After the sacculus was emptied and reinfused, the slope of the linear relationship was determined to be greater than the former slope. The same result was obtained in the lumbar cerebrospinal fluid pressure. Therefore, the lumbar cerebrospinal fluid pressure is consistent with the intracranial pressure. Intracranial pulse pressure is in linear relationship with mean pressure, and the slope of their linear relationship predicts the perform of intracranial autoregulation.