Hypertensive response to raised intracranial pressure in infancy.

Mean arterial pressure and intracranial pressure were measured serially in six infants with intracranial hypertension (intracranial pressure greater than 20 mm Hg), and cerebral perfusion pressure was calculated from their difference. Overall, mean arterial pressure increased with rising intracranial pressure at a mean rate of 0.20 mm Hg/mm Hg. This caused a fall in cerebral perfusion pressure with increasing intracranial pressure at a mean rate of 0.80 mm Hg/mm Hg overall, although cerebral perfusion pressure was well maintained in one infant. Thus the rise in blood pressure was usually insufficient to compensate for the increase in intracranial pressure. In infants with acute encephalopathy vigorous blood pressure support is as important as lowering intracranial pressure.