A ventilating and aspirating assembly comprising an aspirating catheter tube internally disposed within and coextensive with a surrounding flexible collapsible sterility preserving film envelope, a connector by which ventilating air is involuntarily delivered to and exhausted from the lungs of a medical patient, said connector comprising structure which accommodates the manual insertion of the catheter tube into and manual removal from the trachea/bronchi patient through the connector. This facilitates aspiration of undesired respiratory fluids. The assembly further comprises a detachable connection site for one end of the envelope to the connector and a valve by which aspirating vacuum pressure is selectively communicated to the interior of the catheter tube for evacuation of said respiratory fluids, the valve comprising structure isolating the vacuum pressure from the atmosphere, structure by which the valve is placed in either of a locked and an unlocked condition and structure normally biasing and sealing the valve in a closed position, but accommodating manual displacement counter to the bias into an unsealed open position whereby, with the catheter tube indwelling in the lungs of the patient, the vacuum pressure causes evacuation of fluid from the patient's respiratory system through the catheter tube, and a detachable connection site for the other end of the envelope to the valve.