PULMOTOR, a device used for pro ducing artificial respiration. It is used in cases of drowning, asphyxiation by noxious gases and electric shock. There are several types of pulmotor on the market such as the lung motor, the Brat apparatus and the pulmotor. The pul motor which automatically makes the respiratory changes is the most common of the various devices. The air used in the pulmotor is a mixture of atmospheric air and pure oxygen, while in the Brat apparatus pure oxygen is used. The pulmotor consists of a tank of com pressed oxygen, a reducing valve which connects with an injector, from which a mixture of air and oxygen pass through a hose to a face mask. Although the oxygen in the tank approximates chemi cal purity, the mixture which is injected into the lungs averages only about 30 per cent. oxygen, an increase of about 9 per cent. over the amount contained in pure air. A valve mechanism causes al ternate pressure and suction to be ap plied at the face mask. The lung motor consists of a pair of pumps so connected that each one alternately pumps fresh air to the face mask or exhausts the air injected by the other pump. Connec tion may be made to an oxygen tank and the air enriched. It was felt by some
people that the backers of the pulmotor had been somewhat extravagant in the claims which they made for their ap paratus and a committee was appointed to make a scientific study of its actual worth. The committee which was head ed by Professor Yandell Henderson of Yale University acting under the direc tion of the United States Bureau of Mines, made a series of experiments on various animals, but the results obtained were not conclusive. It was found by the investigation that expiration was caused by suction, the extreme strength of which often caused complete collapse of the alveoli and small bronchi, and that air was frequently pumped into the stomach in place of the lungs. Like many other instruments they were found to be dangerous in inexperienced or un skilled hands, and it has been suggested that the instruments be used only as an auxiliary to the established manual methods of artificial respiration and only used for periods of a very few minutes. Many cases of resuscitation by use of the pulmotor reported in the newspapers were, upon investigation, found to be greatly exaggerated.