Carbon dioxide formation increases during states of increased oxidative metabolism. It readily diffuses from parenchymal cells in which it is produced to the vascular smooth muscle of blood vessels where it causes vasodilation.
Does carbon dioxide dilate blood vessels?
Carbon dioxide (CO2) has a profound and reversible effect on cerebral blood flow, such that hypercapnia causes marked dilation of cerebral arteries and arterioles and increased blood flow, whereas hypocapnia causes constriction and decreased blood flow [167,168].
Does low carbon dioxide cause vasoconstriction?
Cerebral blood flow is largely dependent on PaCO2. Hyperventilation causes decreased PaCO2 which subsequently leads to arterial vasoconstriction thus lowering cerebral blood flow (CBF), cerebral blood volume, and ICP.
