Neurosurgeons have long sought a means of epidural measurement of intracranial pressure (ICP), but minute irregularities of the dural surface compromise accuracy when conventional transducers are used to measure epidural pressure (EDP). A silicone rubber-lined pressure transducer developed by the authors prevents the sensor diaphragm from being affected by outside temperature pressure is thus diffusely transmitted across the dural surface so as to diminish stress buildup.
It has been found from the output-depth curves of the experimental model that coplanar measurement minimized the pull of the transducer, and that the angle dependency was negligibly small. Thus, pout-pin curves approached those obtained by directly measuring the hydrostatic pressure. The EDP-IVP slope showed a 45° line with a slight deviation between animals and humans.
The EDP transducer was used in 64 cases for a total of 5, 840 hrs, postoperatively. EDP values varied from zero to above 1, 000 mmH₂O within 3 postoperative days. Besides changes in the basal level of EDP, sudden pressure oscillations, which were classified by Lundberg as A, B and C plateau waves, were observed.
In the plateau wave of A type, EDP rose suddenly to 1, 000 mmH₂O from its base line level, and lasted 5 to 20 minutes. However, variations of B type usually appeared as a rhythmic grouping. These waves were accompanied by hypopnea in the high EDP period, but by hyperpnea or tachypnea in the decreasing course of EDP. Depressed wakefulness in the patient was usually accompanied by B waves.
From the present results, EDP measurement with our EDP transducer was found to be a safe, sure, easy, and extremely useful method for the clinical monitoring of ICP. It has been found that since ICP variations are usually associated with variation in blood pressure, respiration and the wakefulness of the patient, polygraphic observation will be necessary to understand the pathogenesis of ICP.

抄録全体を表示