Experimental cerebral venous oxygen tension under very high intracranial pressure.

Abstract

The cerebral circulation in rabbits was monitored by continuous recording of the cerebral venous oxygen tension (Pcvo2). The intracranial pressure was raised by applying hydrostatic pressure through a catheter introduced into the lumbar subarachnoid space. In the experiments reported here, very high pressures, generally 140 mmHg, were investigated. It was found that in most cases the experimental animals could maintain their cerebral circulation reasonably well for some time, even with such high pressures, and that their tolerance could be raised by infusion of vasopressors. Periodic breathing and oscillations in blood pressure seemed to indicate that the animal had reached its limit of tolerance. When the application of high intracranial pressure was stopped, the Pcvo2 often rose higher than before the application of pressure; considering the report ofHaggendal, Lofgren, Nilsson, andZwetnow (1966) this presumably indicated cerebral hyperaemia.