The dopamine withdrawal test following surgery for intracranial aneurysms.

Cerebral blood flow was measured in eight patients who were being treated with dopamine in order to maintain cerebral perfusion after the onset of delayed postoperative ischaemia following intracranial aneurysm surgery. Measurements were made whilst on treatment and repeated either during a reduction in the dosage or withdrawal of dopamine. There was a significant fall in cerebral blood flow in both hemispheres in all eight patients. Clinical deterioration was observed in seven of nine instances in which cerebral blood flow fell by 25% or more of the value while on dopamine treatment. There were no episodes of deterioration in six tests where the fall in cerebral blood flow was less than 25% of the starting value. It is suggested that cerebral blood flow measurement can be useful in predicting when it is safe to withdraw dopamine treatment in these patients. Hypertensive treatment should be maintained if a withdrawal test is associated with a fall in cerebral blood flow of 25% or more.