Target controlled infusion is a new mode for total intravenous anesthesia, the rational for TCI is based on setting a desired “target” concentration which the device achieves and maintains in plasma. Continuous infusions of intravenous anesthetics and analgesics are now commonly used to induce and maintain sedation and general anesthesia. Any drug can be used in total intravenous anesthesia but drug with more rapid onset and recovery profile is preferred.