What happens to systolic blood pressure when there is increased ICP?

When there is increased intracranial pressure (ICP), systolic blood pressure typically rises. This phenomenon occurs as the body attempts to maintain cerebral perfusion. The brain needs a certain amount of blood flow to function properly, and when ICP increases, it can lead to reduced cerebral perfusion pressure (CPP). To counteract this and ensure that adequate blood reaches the brain, the body responds through a mechanism known as Cushing's reflex. This reflex involves an increase in systemic vascular resistance, resulting in elevated arterial blood pressure, specifically systolic blood pressure.

The rise in systolic blood pressure is a compensatory mechanism to combat the effects of increased pressure within the skull, ensuring that blood continues to perfuse the brain adequately. Therefore, when considering the relationship between increased ICP and systolic blood pressure, one can understand that a rise in systolic pressure is a physiological response aimed at maintaining critical cerebral blood flow.