A gas consisting of 50% oxygen and 50% nitrous oxide that is used as a painkiller during childbirth.
A proprietary analgesic drug taken by inhalation and comprising half nitrous oxide and half oxygen. It is valuable in providing relief to casualties who are in pain, as it provides analgesia without causing unconsciousness. Entonox is also used in obstetric practice to ease the pains of childbirth.
The mentioned brand name refers to a mixture of nitrous oxide and oxygen, utilized to provide pain relief without inducing unconsciousness.