Pharmacology of Inhalational and Intravenous Anesthetic Agents

Abstract

Varying depths of sedation through general anesthesia may be required in critically ill patients during surgical interventions, non-invasive procedures such as magnetic resonance imaging, or invasive procedures such as central line placement. During such procedures, a variety of agents may be chosen to provide the conditions required for a surgical procedure including amnesia, analgesia, muscle relaxation and control of the sympathetic nervous system. The agents used for the induction and maintenance of general anesthesia may be broadly classified into either inhalational (volatile) or intravenous agents. In addition to their use in the operating room for the provision of general anesthesia, both the intravenous and volatile agents may be used outside of the operating for either their sedative properties or even occasionally for their therapeutic effects. Examples include the use of propofol for sedation during magnetic resonance imaging, pentobarbital to control intracranial pressure (ICP) in patients with traumatic brain injury, or the administration of isoflurane for the treatment of status asthmaticus. The following chapter reviews the history, pharmacology, and end-organ effects of the inhalational and intravenous anesthetic agents.