April 14, 2020: Posted by Mohamed Kahna
In response to the Covid-19 pandemic, the United Kingdom is reviving an ancient technology: the iron lung. We look back at the history of this ventilator, which proved its worth in the first half of the 20th century.
Faced with the coronavirus pandemic, the United Kingdom is currently testing a new version of the traditional “iron lung”, as the nation figures out ways to cope with the sudden shortage of required ventilators in this pandemic. The United Kingdom is currently the eighth most affected country by Covid-19, with about 30,000 reported cases, and the sixth most affected in terms of deaths, with more than 2,500 deaths.
Invented in 1927
Recently, a team of doctors, engineers and scientists have been working on the covid ventilator problem. In about ten days, they invented a new version of the “iron lung”, known to have been used extensively in the treatment of polio patients.
The first iron lung machine was invented in 1927 by Americans Philip Drinker and Louis Agassiz Shaw. Originally, it resembled a sealed, cylindrical steel drum in which the patient was laid down.
Pumps periodically increased and decreased the pressure inside the chamber, mimicking pulmonary ventilation and allowing the inhalation and exhalation of air into and out of the lungs.
In polio patients, this iron lung compensated for the paralysis of the diaphragm that made them unable to ventilate naturally, thus preventing death by asphyxiation.
Its first use was in 1928 at Children’s Hospital in Boston, USA, on an unconscious child in respiratory failure. The young patient’s condition improved dramatically within seconds of being placed in the breathing chamber.This contributed greatly to the success of the “Drinker ventilator”, later dubbed the “iron lung”.
The return of the good old iron lung
In the 1940s and 1950s, “iron lung” was therefore the official treatment for polio, before vaccination programmes, which largely eradicated the disease, and the advent of modern mechanical ventilation, by direct airway intubation, gradually put it on the back burner.
In the case of Covid-19, the principle of the iron lung could be used again, in a modern version called Exovent. This new ventilator can be used both for patients with breathing difficulties and requiring respiratory assistance, and for intensive care.
The modern artificial lung, called Exovent
Much less imposing than the cylinders of yesteryear, the modern artificial lung, called Exovent, consists of a box placed, or rather sealed, on the ground including the patient’s chest and abdomen. “It’s a non-invasive method of ventilation, cheaper and easier, and it works at least as well, if not better, than traditional ventilation,” Dr. Malcolm Coulthard of Newcastle’s Great North Children’s Hospital told the British newspaper The Independent. He is one of the experts who helped develop the Exovent.
The manufacture of these new ventilators, for which their inventors are not claiming rights, would cost around €1,100 per machine, about ten times less than current ventilators.
This is undoubtedly good news for the NHS (National Health Service), the British health system, to which the government had promised only 30 new artificial respirators, again according to The Independent.
But if the government gave the go-ahead, 5,000 copies of the new cheap and easy-to-manufacture “iron lung” could be delivered every week.