Abstract

The effects of discrete increases in the volume of an artificial space-occupying lesion on intracranial pressures and the systemic circulation were studied in six anaesthetised and artificially ventilated dogs. Each increase in volume, accompanied by an increase in supratentorial intracranial pressure, a decrease in supratentorial perfusion pressure, and an increase in transtentorial pressure gradient, induced alterations in the systemic circulation. There were a decrease in heart rate, marked alterations in the arrhythmia index, and increases in stroke volume and systemic vascular resistance. A period of transient systemic hypertension was noted to accompany each discrete increase in intracranial pressure.