Sedation is a medical term referring to the act of calming a person by giving him drugs (sedatives). Sedatives depress the central nervous system and relieve anxiety and discomfort. Doctors use sedation for a variety of reasons; the most common is to calm patients who are undergoing difficult surgical or diagnostic procedures, especially those that require the patient to remain still for long periods, such as magnetic resonance imaging. Dentists sometimes use sedatives before long procedures.
Different levels of sedation include minimal, in which the patient is just relieved of anxiety; moderate, in which the patient can still respond to verbal commands and touch; deep, in which the patient is unconscious but still responds to painful stimuli; and general anesthesia, or the state of unconsciousness used during surgeries. It takes skill and training to administer drugs in the appropriate amounts to achieve and maintain these different levels, especially in pediatric medicine. Anesthesiologists classify patients in terms of their healthiness and risk factors before they administer sedatives.
Drugs commonly used to for sedation include benzodiazepines, barbiturates, non-barbiturate sedatives such as propofol and etomidate, opioids such as morphine, fentanyl and meperidine, and inhaled sedatives such as nitrous oxide.