Pulmotor
Collier's New Encyclopedia (1921)
a device used for producing artificial respiration. It is used in 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 pulmotor which automatically makes the is the most common respiratory changes res 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 compressed 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 che chemical purity, the mixture which is injected into the lungs averages only about 30 per cent. oxygen, an increase of about 9 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. Connection may be made to an oxygen tank and the air enriched. It was felt by some that the backers of the pulmotor people had been somewhat extravagant in the claims which they made for their apparatus and a committee was appointed to make a scientific study of its actual worth. The committee which was headed by Professor Yandell Henderson of Yale University acting under the direction 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 25 of the alveoli and small bronchi, and that air was frequently pumped pumped into the stomach in place of the lungs. Like many other instruments they were found to be dangerous in inexperienced or unskilled 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.
What Has Changed in the Last Century
The Collier's writer of 1921 was right to be sceptical: the pulmotor, patented by the Dräger works in Germany in 1907 and sold hard to fire and rescue services, is long obsolete, and the suction-driven expiration that Yandell Henderson's Bureau of Mines committee found collapsed the alveoli is exactly why such automatic resuscitators were abandoned. The "established manual methods" Collier's recommended instead — pressing on a prone victim's back — went the same way. Rescue breathing today rests on mouth-to-mouth technique popularised by Peter Safar in the 1950s, the self-inflating bag-valve-mask introduced by Holger Hesse and Henning Ruben in 1956, and closed-chest cardiac compression demonstrated by Kouwenhoven and colleagues in 1960; the three were combined into modern CPR. Oxygen cylinders and face masks remain standard equipment, but nothing forces gas into a casualty's lungs and then sucks it back out.
Written for this edition, 2026.