inhalation anaesthesia , także: inhalation anesthesia AmE

Many compounds have been used for inhalation anaesthesia, but only a few are still in widespread use.

Piramal Critical Care (Inhalation anaesthesia gases business)

He continued, and extended, Snow's work on inhalation anaesthesia and brought into clinical use, no less than fourteen anaesthetics, of which methylene bichloride is the best known, and he invented the first double-valved mouthpiece for use in the administration of chloroform.