Cerebral Circulation and Cerebral Blood Flow

Cardiac arrest occurs suddenly, often without premonitory symptoms. Consciousness is lost within seconds to minutes because of insufficient cerebral blood flow in the midst of complete hemodynamic collapse. Anoxic-ischemic brain injury is most commonly caused by cardiac arrest, which is frequently lethal; of the US patients with out-of-hospital cardiac arrest treated by emergency medical services, almost 90% die. Among the patients who survive to hospital admission, inpatient mortality may be decreasing, but a substantial number of those survivors have poor neurologic outcomes from anoxic-ischemic brain injury.