A colourless gas used as an anaesthetic with good analgesic properties. It is administered by inhalation, in conjunction with oxygen and other agents, for the maintenance of anaesthesia. A mixture of oxygen and nitrous oxide (Entonox, Equanox) provides effective analgesia for some dental procedures and in childbirth; such a state is known as relative analgesia. Nitrous oxide was formerly referred to as laughing gas because of its tendency to excite the patient when used alone.
Subjects: Medicine and Health — Science and Mathematics.