The ability of an organ or vascular bed to maintain adequate blood flow despite varying blood pressure is termed autoregulation. Metabolic regulation controls about 75% of all local blood flow in the body. Organs have differing ability (autoregulatory reserve) to increase or decrease their vascular resistance to provide tight coupling between metabolic demand and organ blood flow. Anesthetic agents that cause vasodilation inhibit organ autoregulation. Under these conditions, organ perfusion is more dependent on systemic blood pressure.