An apparatus for reversing inhaled anesthesia includes a filter for removing one or more anesthetic agents from gases passing therethrough, as well as a component for elevating CO.sub.2 levels in gases that are to be inhaled by a subject. The CO.sub.2 level-elevating component facilitates an increase in the ventilation of the subject without resulting in a significant decrease in the subject's P.sub.aCO.sub.2 level and, thus, a decrease in the rate at which blood flows through the subject's brain. A method of reversing the effects of inhaled anesthesia includes increasing the rate of ventilation of an anesthetized subject while causing the subject to inhale gases with elevated amounts of CO.sub.2 and while filtering anesthetic agents from such gases.