Effects of rapid blood pressure reduction on cerebral blood flow.

The changes that occur in the cerebral circulation with chronic hypertension are important when considering the therapeutic possibilities in treating patients with severe hypertension. Care must be taken not to lower the blood pressure below the lower limit of autoregulation, no matter what drug is used. In patients with severe, chronic hypertension, blood pressure should be lowered carefully. Rapid blood pressure reduction to a level that is below the lower limit of autoregulation may result in central nervous system dysfunction due to cerebral hypoperfusion. This is especially true in patients with increased intracranial pressure and cerebral edema such as those with hypertensive encephalopathy.