Drinker and Shaw Develop a Mechanical Respirator

Date July, 1929

Philip Drinker and Louis Shaw developed the mechanical respirator known as the iron lung, a lifesaving device for victims of poliomyelitis that led to the development of other lifesaving respiratory care.

Also known as Iron lung

Locale Harvard University, Massachusetts

Key Figures

• Philip Drinker (1894-1972), American engineer
• Louis Shaw (1886-1940), American respiratory physiologist

Summary of Event

Poliomyelitis (polio, or infantile paralysis) is an infectious viral disease that damages the central nervous system, causing paralysis in many serious cases. Its effects result from the destruction of neurons (nerve cells) in the spinal cord. In many cases, the disease produces crippled limbs and the wasting of muscles. In others, “anterior” polio results in the fatal paralysis of the respiratory muscles. Since the 1950’s, use of the Salk and Sabin vaccines has virtually eradicated polio, but in the 1920’s, it was a terrifying disease. Its most feared, untreatable outcome was the paralysis of the respiratory muscles, which caused rapid death by suffocation, often only a few hours after the first signs of respiratory distress appeared.

In 1929, Philip Drinker and Louis Shaw, both of Harvard University, published an article in the Journal of Clinical Investigation in which they reported on their development of a mechanical respirator that would keep those afflicted with the disease alive for indefinite periods of time. This device, soon nicknamed the “iron lung,” provided essential life support for thousands of people who suffered from respiratory paralysis as a result of polio or other diseases. It was used for many years, but as John A. Meyer, a thoracic surgeon, noted in a 1990 article, iron lungs are now primarily “fascinating relics, reminders of high tech medicine of an earlier day.” This comment is corroborated by the fact that as of 1986, a survey found that only three hundred iron lungs remained in use in the United States.

Development of the iron lung arose after Drinker, then an assistant professor in Harvard’s Department of Industrial Hygiene, was appointed to a Rockefeller Institute commission formed to develop improved methods for resuscitating victims of electric shock and illuminating gas poisoning. The best-known use of the iron lung—treatment of polio—was a result of numerous epidemics of the disease that occurred from 1898 until the 1920’s, each leaving thousands of Americans paralyzed. The concept of the mechanical respirator reportedly arose from Drinker’s observation of physiological experiments carried out by Shaw and Drinker’s brother, Cecil. Those experiments were components of an effort to design artificial respiration methods that would enhance a patient’s survival after surgery.

The experiments involved the placement of a cat inside an airtight box—a body plethysmograph—with the cat’s head protruding from an airtight collar. Shaw and Cecil Drinker then measured the volume changes in the plethysmograph to identify normal breathing parameters. Philip Drinker placed cats paralyzed by curare inside plethysmographs and showed that they could be kept breathing artificially by use of air from a hypodermic syringe connected to the device. Next, they proceeded to build a human-sized plethysmograph-like machine, using a five-hundred-dollar grant from the New York Consolidated Gas Company. The device’s construction was carried out by a tinsmith and the Harvard Medical School machine shop.

The prototype machine was tested on Drinker and Shaw, and after they made several modifications, a workable iron lung was available for clinical use. It consisted of a metal cylinder large enough to accommodate a patient. One end of the cylinder, which contained a rubber collar, slid out on casters along with a stretcher on which the patient reclined. Once the patient was in position and the collar was fitted around the patient’s neck, the stretcher was pushed back into the cylinder and louvers were secured to make the iron lung airtight. The iron lung then “breathed” for the patient by using an electric blower to remove and replace air alternately.

In the human chest, inhalation occurs when the diaphragm contracts and powerful muscles expand the rib cage. This lowers the air pressure in the lungs and allows inhalation to occur. In exhalation, the diaphragm and chest muscles relax, and air is expelled as the chest cavity reduces again in size. In a case of respiratory paralysis treated with an iron lung, intake of air into and expulsion of air from the iron lung alternately compress the patient’s chest, producing artificial exhalation, and allow it to expand so that it can fill with air. In this way, the iron lung “breathes” for the patient.

Careful examination of each patient was required to allow optimum adjustment of the rate of operation of the machine. The device also included a cooling system and ports for drainage lines, intravenous lines, and other apparatus needed to maintain a wide variety of patients.

The first person treated in an iron lung was an eight-year-old girl afflicted with respiratory paralysis resulting from polio. The iron lung kept her alive for five days. Unfortunately, she died from cardiac failure as a result of pneumonia. The next iron lung patient, a Harvard University student, was confined to the machine for several weeks and later recovered enough to resume a normal life. Use of the iron lung thereafter rapidly entered hospital practice. As Meyer described in 1990, “Treatment facilities tended to concentrate at university and city-county hospitals, each with its Respirator Center, where long lines of Drinker tank respirators were lined up side by side.”

As James H. Maxwell pointed out in a 1986 article, one problem that limited maximum use of the iron lung came from physicians’ fears that their patients would be “forever tethered to the lung.” Such fears often led to inappropriate delays before patients were placed in the respirators, although in fact only a small percentage of patients became chronically dependent on the machines.

Significance

Soon after the iron lung, also known as the Drinker respirator, came into use in 1929, the device came to be considered indispensable. Until the Salk vaccine became available in the 1950’s, iron lungs saved the lives of countless victims of polio as well as other diseases. As Meyer noted in 1990, “no satisfactory mechanical respirator existed before” the iron lung, and for a quarter of a century it was the sole reliable machine of its kind, “a lifeline for thousands of patients afflicted with respiratory failure caused by poliomyelitis.”

Drinker received a number of honors for his development of the iron lung, including Philadelphia’s John Scott Medal (shared with Louis Shaw, in 1931), the Charles Chapin Memorial Award (1948), and the Cummings Memorial Award of the American Industrial Hygiene Association in 1950. He was also made an honorary member of England’s Royal Society of Health and the Finnish Industrial Medical Society. He was elected president of the American Industrial Hygiene Association in 1942, and he also became chairman of Harvard’s Department of Industrial Hygiene.

It is generally acknowledged that the medical community’s acceptance and use of the iron lung played a critical role in the development of modern respiratory care. For one thing, as Maxwell has noted, “use of the iron lung proved that large numbers of patients could actually be kept alive with mechanical support.” Not all assessments are in agreement as to the device’s importance, however. For example, H. H. Bendixen, an anesthesiologist, suggested in a 1982 article that the iron lung “must be called a technological detour, despite the fact that it has had life-saving clinical use.” He also asserted that although the iron lung “became the mainstay of poliomyelitis treatment” until the 1950’s, “the mortality rate remained high and was not significantly reduced” until combined intermittent positive pressure breathing was combined with the use of the iron lung.

Bibliography

Bendixen, H. H. “Respirators and Respiratory Care.” Acta Anaesthesia Scandinavica 102 (1982): 279-286. Review article by an anesthesiologist traces “intellectual and technical roots of respirators and respiratory care,” identifies the role of polio in these developments, and addresses the roles of respirators and anesthesiology in modern respiratory care.

Black, Kathryn. In the Shadow of Polio: A Personal and Social History. New York: Perseus Books, 1996. Memoir relates the author’s mother’s two-year battle with polio, much of which she spent confined to an iron lung. Also provides information on efforts to combat the disease before a vaccine was available.

Drinker, Philip, and Charles F. McKhann, III. “The Iron Lung, First Practical Means of Respiratory Support.” Journal of the American Medical Association 255 (1986): 1476-1480. Article written by the son of Philip Drinker and one of his major medical collaborators summarizes Drinker’s development of the machine, comments on earlier respiratory devices, describes use of the iron lung in polio epidemics, and identifies later evolution of respiratory care. Provides useful insight into Drinker’s life. Includes photographs of activated iron lungs.

Drinker, Philip, and Louis Shaw. “An Apparatus for the Prolonged Administration of Artificial Respiration.” Journal of Clinical Investigation 7 (1929): 229-247. Describes in depth the development and first uses of the iron lung. Enumerates the theoretical and practical aspects of the respirator’s design as well as the developers’ hopes for its future use.

Maxwell, James H. “The Iron Lung: Halfway Technology or Necessary Step?” Milbank Quarterly 64 (1986): 3-28. Describes the history and development of the iron lung, examines its clinical utility and cost, the strengths and weaknesses of its use, and its role in the evolution of respirators and respiratory care. Includes references.

Meyer, John A. “A Practical Mechanical Respirator, 1929: The ’Iron Lung.’” Annals of Thoracic Surgery 50 (1990): 490-493. Describes the iron lung and discusses its development as a valuable therapeutic possibility and its use in polio epidemics. Concludes that, although the iron lung was cumbersome, “it supported patients over the long term with fewer complications than do the respirators of today.”

“Philip Drinker.” In The National Cyclopedia of American Biography. Vol. 57. Clifton, N.J.: James T. White, 1977. Brief biographical sketch is one of the only readily available sources of information on Drinker’s life and work. Includes aspects of his early life as well as his education, career, and accomplishments.