Intravenous Anesthetic Agents

Abstract

Intravenous (IV) anesthetics are used in the operating room setting for the induction and maintenance of general anesthesia. These agents are used in combination with many other therapeutic agents including inhalational anesthetics, anticholinergics, neuromuscular blockers, local anesthetics, and antihistamines. Currently available intravenous anesthetics include barbiturates (eg, thiopental and methohexital), benzodiazepines (eg, diazepam and midazolam), etomidate, ketamine, propofol, and opioids (eg, morphine, meperidine, fentanyl, alfentanil, and sufentanil). The barbiturates are the most frequently used agents for induction today. The benzodiazepines are used primarily for preoperative sedation intraoperatively; however, they may also be used for induction in certain clinical situations. Etomidate offers the advantage of minimal cardiovascular side effects, while ketamine is distinguished by stimulant cardiovascular effects. Propofol has a short recovery time and a low incidence of nausea and vomiting when compared with that of barbiturates and opioids. The opioids are used most often for the production of analgesia, although they may also be used as primary anesthetic agents in select patient populations. In this article, the pharmacokinetics of these agents will be reviewed as well as factors affecting their pharmacokinetic profile. These factors include age, hemodynamic changes, renal or hepatic dysfunction, and interaction with concomitant medications.