The Venturi anaesthesia circuit I. An all-purpose breathing system for anaesthesia.

The Venturi is a flow-accelerating injector, activated by fresh gas inflow from the anaesthetic machine. The Venturi entrains exhaled gas from the patient through a soda-lime canister, and carries it to the patient together with fresh gas. The Venturi circuit is a Mapleson D system and the fresh gas requirements are roughly 30 ml kg-1 min-1 for anaesthetized, relaxed, adult patients under controlled ventilation.