An instrument which circumvents objectionable aspects of mouth-to-mouth contact when this method of resuscitation is used has been devised. A simple nose and mouth mask, a flutter valve, and an outflow valve prevent the flow of expired air from the injured person to the operator. An inflow valve on the operator's side of the flutter valve provides fresh air. The length of the tube allows the operator to first rebreathe 300 cc. of his previously exhaled air and prevents him from hyperventilating. A relief valve opens when ventilation pressures exceed 24 mm. Hg. The mechanical and physiological efficacy was checked by laboratory testing of the exchanged air and of blood samples drawn from five subjects during actual resuscitative conditions. The mouth-to-mask method of artificial respiration proves to be safe, simple, and efficient.
Tomashefski JF, Oliver TK. MOUTH-TO-MASK RESUSCITATION. JAMA. 1960;172(17):1888-1890. doi:10.1001/jama.1960.03020170014003