Small artery and vein pressures in the subarachnoid space of the dog

Abstract

Summary The mean arterial pressure in vessels of 0.5 mm. diameter in the subarachnoid space is in the range of 63 mm. Hg, which is less than 50 per cent of mean systemic blood pressure. In the small veins of this space, the pressure is in the range of 255 mm. H 2 O (19 mm. Hg) with a gradient of pressure between subarachnoid vein and membranous sagittal sinus of approximately 150 mm H 2 O. A major determinant of SAVP is CSFP, and elevations of the latter increase subarachnoid venous pressure without elevating sagittal sinus venous pressure.