iron lung

iron lung. The iron lung, formally known as the Drinker respirator, is a type of negative pressure ventilator that encases a patient's body to assist breathing. It was a critical life-support device, most famously used during the polio epidemics of the mid-20th century. The machine works by rhythmically altering air pressure around the patient's torso, forcing the lungs to expand and contract.

History and development

The device was invented in 1927 by Philip Drinker and Louis Agassiz Shaw at Harvard University, with significant improvements later made by engineer John Haven Emerson. Its development was spurred by the need to treat respiratory failure from diseases like bulbar polio, which paralyzed the chest muscles. A pivotal early case involved an eight-year-old girl at Boston Children's Hospital, whose survival demonstrated the machine's potential. During the devastating 1952 polio epidemic in the United States, hospitals like the Rancho Los Amigos Hospital in California filled entire wards with rows of the devices. The design was notably refined for mass production by companies including J. H. Emerson Company, and its use spread globally to institutions such as the Hugh MacMillan Rehabilitation Centre in Toronto.

Medical use and mechanism

The patient is placed inside a sealed cylindrical metal tank with their head protruding through a rubber collar. A pump, often powered by an electric motor, cyclically reduces and restores air pressure within the chamber. This negative pressure pulls the patient's chest wall outward, drawing air into the lungs through the normal airway, mimicking the action of the diaphragm. It was primarily indicated for patients with paralysis of the respiratory muscles, most commonly from poliomyelitis, but also from conditions like Guillain-Barré syndrome and botulism. Care required constant monitoring by nurses and physicians for complications such as pneumonia or circulatory issues, with some patients dependent on the apparatus for decades.

Impact and legacy

The iron lung is credited with saving thousands of lives, becoming an iconic symbol of the fight against polio and the terror of epidemics. It led to the creation of specialized respiratory care units and advanced the field of rehabilitation medicine. The device also highlighted profound ethical and social challenges, as long-term patients, such as Martha Mason and Dianne Odell, lived full, productive lives entirely within their machines, relying on caregivers and technology. The widespread use of the iron lung galvanized public support for the March of Dimes, which funded both patient care and the research by Jonas Salk and Albert Sabin that ultimately led to effective vaccines.

Modern alternatives and decline

The introduction of the polio vaccine in the 1950s drastically reduced the incidence of new cases requiring long-term ventilation. Clinically, the iron lung was largely superseded by positive pressure ventilators, such as the Bennett PR-2 and modern intensive care unit ventilators, which are less cumbersome and allow for easier patient access. Today, only a handful of individuals worldwide, primarily polio survivors, continue to use updated versions of the iron lung, often by personal preference. Modern negative pressure devices like the cuirass ventilator or the Porta-Lung offer more portable alternatives for some patients with chronic respiratory failure.

Cultural references

The iron lung has been depicted in numerous films, including The Last Polio and the biographical drama Breathe (2017 film). It appears in literature, such as in Philip Roth's novel Nemesis, and in music, notably as the title of a song by the band Radiohead on their album The Bends. The device is frequently featured in historical documentaries about polio and public health, and several original iron lungs are preserved in museums like the Smithsonian Institution and the Science Museum, London, serving as powerful reminders of a pre-vaccine era.