Journal of neurosurgical anesthesiology
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J Neurosurg Anesthesiol · Jul 1992
Cerebral blood flow at constant cerebral perfusion pressure but changing arterial and intracranial pressure: relationship to autoregulation.
Therapeutic agents for reducing raised intracranial pressure (ICP) may do so at the expense of reduced mean arterial pressure (MAP). As a consequence, cerebral perfusion pressure (CPP) = (MAP - ICP) may not improve. It is unknown whether the level of MAP alters cerebral blood flow (CBF) when MAP and ICP change in parallel so that CPP remains constant. ⋯ At a CPP of 40 mm Hg, CBF showed a linear correlation with blood pressure (BP) (r = 0.57, p <0.05). These results demonstrate that when autoregulation is impaired, there is a functional difference between autoregulating and nonautoregulating cerebral vessels despite similar MAP and CPP. These results also show that at a CPP of 40 mm Hg when autoregulation is impaired, CBF depends more on arterial driving pressure than on CPP.