CEREBRAL BLOOD-FLOW AND INTRACRANIAL-PRESSURE DURING EXPERIMENTAL SUBARACHNOID HEMORRHAGE

The relationships of intracranial pressure (ICP), systemic blood press ure (SBP) and cerebral blood flow (CBF) during experimental subarachno id haemorrhage were investigated in cats. Continuous monitoring of reg ional cerebral blood flow (rCBF) was done by a thermal diffusion metho d using a Peltier stack. During haemorrhage ICP rose within 5.4 +/- 0. 97 minutes from 10.5 +/- 4.9 to 176.1 +/- 27.8 mmHg. This strong incre ase of ICP resulted in a temporary arrest of cerebral circulation. The Cushing response during the haemorrhage could not improve the cerebra l circulation, but in contrast caused a further increase of ICP. After the haemorrhage the cerebral blood flow normalised within minutes. It is concluded, that the Cushing response during a subarachnoid haemorr hage should be regarded as a deleterious rather than a beneficial mech anism.