Iron lung

[
Rancho Los Amigos Hospital, California. 1953] An iron lung is a large machine that enables a person to breathe when normal muscle control has been lost or the work of breathing exceeds the person's ability. It is a form of medical ventilator. Properly, it is called a negative pressure ventilator.

Method and use

The person using the iron lung is placed into the central chamber, a cylindrical steel drum. A door allowing the head and neck to remain free is then closed, forming a sealed, air-tight compartment enclosing the rest of the person's body. Pumps that control airflow periodically decrease and increase the air pressure within the chamber, and particularly, on the chest. When the pressure falls below that within the lungs, the lungs expand and atmospheric pressure pushes air from outside the chamber in via the person's nose and airways to keep the lungs filled; when the pressure rises above that within the lungs, the reverse occurs, and air is expelled. In this manner, the iron lung mimics the physiologic action of breathing: by periodically altering intrathoracic pressure, it causes air to flow in and out of the lungs. The iron lung is a form of non-invasive therapy.

Invention and progression

The machine was invented by Philip Drinker and Louis Agassiz Shaw, of the Harvard School of Public Health, originally for treatment of coal gas poisoning. But it found its most famous use in the mid-1900s when victims of poliomyelitis (more commonly known as polio), stricken with paralysis (including of the diaphragm, the cone shaped muscle at the bottom of the rib-cage whose action controls intrathoracic pressure), became unable to breathe, and were placed in these steel chambers to survive. The first iron lung was used on October 12, 1928 at Children's Hospital, Boston, in a child unconscious from respiratory failure; her dramatic recovery, within seconds of being placed within the chamber, did much to popularize the "Drinker Respirator." [ cite web | title = OCCUPATIONAL SAFETY AND HEALTH AT HARVARD UNIVERSITY | url = http://www.hsph.harvard.edu/erc/somehistory.html | publisher = The Harvard Education and Research Center |accessdate = 2007-10-12]

In 1931, inveterate tinkerer John Haven "Jack" Emerson unveiled a less expensive iron lung. [ cite web | title = Iron Lung | publisher = National Museum of American History | url = http://americanhistory.si.edu/collections/object.cfm?key=35&objkey=114 |accessdate = 2007-10-12 ] Drinker and Harvard promptly sued Emerson for patent violations, which proved unwise. In the subsequent legal battles Emerson demonstrated that every aspect of Drinker's patents had been patented by others at earlier times. Emerson won the case, and Drinker's patents were declared invalid.

Entire hospital wards were filled with rows of iron lungs at the height of the polio outbreaks of the 1940s and 50s. With the success of the worldwide polio vaccination programs which have virtually eradicated new cases of the disease, and the advent of modern ventilators that control breathing via the direct intubation of the airway, the use of the iron lung has sharply declined.

Modern usage

Positive pressure ventilation systems are now more common than negative pressure systems. Positive pressure ventilators work by blowing air into the patient's lungs via intubation through the airway; they were used for the first time in Blegdams Hospital, Copenhagen, Denmark during a polio outbreak in 1952. [ cite web | title = Chapter 4: Theaters of truth and competence. Intermittent positive pressure respiration during the 1952 polio-epidemic in Copenhagen | first = Ger | last = Wackers | url = http://www.fdcw.unimaas.nl/personal/WebSitesMWT/Wackers/proefschrift.html#h4 | year = 1994 |accessdate = 2007-10-12] It proved a success and soon superseded the iron lung throughout Europe.

The iron lung now has a marginal place in modern respiratory therapy. Most patients with paralysis of the breathing muscles use modern mechanical ventilators that push air into the airway with positive pressure. These are generally efficacious and have the advantage of not restricting patients' movements or caregivers' ability to examine the patients as significantly as an iron lung does. However, negative pressure ventilation is a truer approximation of normal physiological breathing and results in more normal distribution of air in the lungs. It may also be preferable in certain rare conditions, such as Ondine's curse, in which failure of the medullary respiratory centers at the base of the brain result in patients having no autonomic control of breathing. At least one reported polio patient had a spinal deformity that caused the use of mechanical ventilators to be contraindicated. [ cite web | title = Power failure kills iron lung lady | url = http://www.smh.com.au/news/world/power-failure-kills-iron-lung-lady/2008/05/29/1211654160059.html | year = 2008 |accessdate = 2008-05-29] Thus, there are patients who today still use the older machines, often in their homes, despite the occasional difficulty of finding the various replacement parts. Joan Headley of Post-Polio Health International stated to CNN that there are approximately 30 patients in the USA still using an iron lung [ [http://www.cnn.com/2008/US/05/28/iron.lung.death.ap/index.html Woman dies after life spent in iron lung] From CNN, Wed May 28, 2008]

The iron lung was shown in a short scene in the film The Big Lebowski in full use.

Biphasic Cuirass Ventilation is a modern development of the iron lung, consisting of a wearable rigid upper-body shell (a cuirass) which functions as a negative pressure respirator.

References


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Look at other dictionaries:

  • iron lung — i ron lung , n. A steel chamber, usually cylindrical, enclosing the entire body of a person except for the head, used to assist respiration for people suffering from disease, especially poliomyelitis. A reciprocating piston at the end causes… …   The Collaborative International Dictionary of English

  • iron lung — n a device for artificial respiration in which rhythmic alternations in the air pressure in a chamber surrounding a patient s chest force air into and out of the lungs esp. when the nerves governing the chest muscles fail to function because of… …   Medical dictionary

  • iron lung — n a large machine with a metal case used to help people to breathe …   Dictionary of contemporary English

  • iron lung — ► NOUN ▪ a rigid case fitted over a patient s body, used for administering prolonged artificial respiration by means of mechanical pumps …   English terms dictionary

  • iron lung — ☆ iron lung n. a large metal respirator that encloses all of the body but the head, used for maintaining artificial respiration in a person who has difficulty in breathing as a result of poliomyelitis, gas poisoning, etc …   English World dictionary

  • iron lung — wouldn t work in an iron lung Extraordinarily lazy. The phrase derives from the artificial respirator that kept polio patients alive by breathing for them in the days when up to ten thousand people annually were affected by poliomyelitis (… …   Australian idioms

  • iron lung — /aɪən ˈlʌŋ / (say uyuhn lung) noun 1. a chamber in which alternate pulsations of high and low pressure can be used to force normal lung movements, used especially in some cases of poliomyelitis. –phrase 2. wouldn t work in an iron lung,… …   Australian English dictionary

  • iron lung — Synonyms and related words: Aqua Lung, artificial respiration, aspiration, asthmatic wheeze, breath, breath of air, breathing, broken wind, cough, exhalation, expiration, exsufflation, gasp, gulp, hack, hiccup, inhalation, inhalator, inspiration …   Moby Thesaurus

  • iron lung — i′ron lung′ n. med a rigid respirator that encloses the whole body except the head and in which alternate pulsations of high and low pressure induce normal breathing movements or force air into and out of the lungs …   From formal English to slang

  • iron lung — noun Date: 1932 a device for artificial respiration in which rhythmic alternations in the air pressure in a chamber surrounding a patient s chest force air into and out of the lungs …   New Collegiate Dictionary

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