Twilight sleep anesthesia or monitored anesthesia care (MAC) is a specific anesthesia which is administered through intravenous anesthetic drugs to make the patient sleepy (but actually the person is awake). During the surgery, an anesthesia professional needs to be present continuously to monitor the patient' s vital signals, maintenance of patient airway and administer the sedatives to ensure patient safety. In MAC trachea is not incubated like in the case of general anesthesia. It is considered that the patient is able to protect the airway for the majority of the therapeutic procedure.

This type of anesthesia is generally used in minor surgical processes and dental procedures to provide the patient relief from pain, general fear of surgery and anxiety. The twilight anesthesia can be combined with local or regional anesthesia.

Since, lower doses of anesthetic drugs are given in MAC; the recovery period is generally short.