The use of iron lungs as treatment for polio

In 1928, the first patient to use the iron lung was an eight-year-old girl, suffering from respiratory paralysis as a result of poliomyelitis, or polio. Though she later died from cardiac failure, the device, an artificial respirator, had kept her breathing — and alive — for over five days. 

Designed by industrial hygienist Philip Drinker and physiologist Louis Agassiz Shaw Jr., both of Harvard University, the device would continue to be associated with polio, gaining prominence as both a life-saving invention and a frightening symbol of the disease’s potential effects. 

Before Drinker and Shaw’s invention, there were few methods for inducing artificial respiration. 

Beginning in 1782, the Royal Humane Society of England recommended the use of bellows to inflate a patient’s lungs, a method that fell out of use in the 1830s. 

In the late 1850s, Henry Silvester developed a technique that involved pulling a patient’s arms above the head, then lowering them and pressing sideways on the chest to manually adjust the ribcage. 

For several years this procedure was used in Great Britain and some parts of Europe to resuscitate drowned individuals. 

Later developments included a box designed for children, in which air was pushed in or sucked out through a tube. 

In 1918 Dr. W. Steuart created a device that involved an air-tight compartment that enclosed a patient’s torso. The device was connected to bellows that could create a partial vacuum. Although this apparatus was closest in design to the eventual iron lung, Steuart did not appear to have developed it significantly. 

The iron lung, also known as the tank respirator or the Drinker respirator, consisted of a large cylindrical metal tank, one end sealed and the other covered in a flat lid with an embedded rubber collar. The patient was entirely enclosed in the apparatus except for the head and neck, which stuck out through the collar. 

This device, mimicking natural human respiration, operated on the principle of negative pressure. In normal human respiration, the diaphragm contracts, the ribs are pulled outwards and the lungs are allowed to expand, decreasing the air pressure inside. 

Air then moves from the atmosphere to the lower pressure environment of the lungs. The inverse happens during expiration.

In the iron lung, pressure differentials were created by raising and lowering the pressure inside the tank. 

The tank was also studded with portholes, through which the patient could be observed, as well as smaller openings for thermometers other instruments. 

The design was later modified by John Haven Emerson, whose version, released in 1931, proved to be cheaper, lighter and less noisy.

Drinker and Shaw originally recommended their device to treat patients with respiratory failure from a variety of causes, including carbon monoxide or morphine poisoning and electrocution, but the iron lung was the most well-known and in-demand for its use for patients with polio.

Polio had haunted summers in America for almost the entire first half of the 20th century. Although outbreaks peaked in the 1940s and 1950s, between 1910 and 1945, at least 1000 cases were reported per year in the U.S. 

Around one percent of people who contracted polio ended up with the paralytic type. Fewer still suffered from the respiratory paralysis caused when the virus attacked the nervous system, including the nerves that control the diaphragm. 

Still, chilling scenes of hospital rooms lined with iron lungs, in some cases stacked on top of one another, often encasing children, remained present in the public’s mind. Some patients remained in an iron lung for weeks, others for years. 

While feared, the iron lung was immensely useful. 

Prior to its invention and widespread implementation, when polio cases peaked sharply, such as in 1916, so did deaths. 

After the mid-1930s, however, polio deaths were not as strongly correlated with large outbreaks. 

During a 1949 epidemic, there were over 10,000 more cases than in 1916, but there were fewer than half as many deaths as in 1916. During a 1952 epidemic, the number of cases was over twice that as in 1916, and the number of deaths was comparable with the 1949 outbreak. 

Philip Drinker and engineer Edgar Roy even provided a design for a makeshift iron lung, created from easily-obtained household items, in the case of an emergency. 

After the development of Jonas Salk and Albert Sabin’s polio vaccines in the mid-1950s through early 1960s, polio cases dropped off dramatically in America and so did the use of iron lungs. In 1959, there were over 1000 patients in iron lungs; by 2004, there were 39. 

In the present day, artificial respiration is usually achieved through ventilators and endotracheal or tracheostomy tubes. The iron lung, in turn, is fated to become a thing entirely of the past.