An adapter includes a housing having an inlet port defining a flow path and anoutlet port. An interior wall has an innersurface defining an interior passageway communicating with the outler port anden exterior surface defining an exterior passage-waycommunicating with the inlet port. The interior wall defines a monthcommunicating between the interior and the exterior passage-ways,The interior wall is positioned transverse to the flow path of the inlet port.A medicament delivery port, opens into themouth. A valve is moveable between a closed position. wherein the valve closesthe medicament delivery port, and an open position,wherein the medicament delivery port is open. A ventilator circuit and methodof delivering a medicament are also provided.
