Abstract: A rescue breathing device or insufflator is shown for providing mouth-to-mouth artificial resuscitation to a victim of suffocation or asphyxiation. The device has a tubular body comprising an input portion and an output portion. The tubular body has a central axial air passageway converging in cross-sectional area in the input portion to a central venturi region. At least one fresh air port communicates with the venturi region. The air passageway in the output portion diverges or is of constant cross-sectional area, so that a venturi effect is produced when the device is used, resulting in the venturi mixing fresh ambient air with the respirated air provided to an asphyxiation victim by a rescuer, thereby increasing the oxygen content of the air delivered to the victim by the resuscitation process. A shield is removably mounted on the tubular body to provide a good seal and prevent lip contact between the rescuer and the victim.