The year 2020 came with lots of baggage, among which is the COVID-19 pandemic. The pandemic has affected people in varying degrees from mild to severe, most infected people always have a not so good story to tell about the novel disease, especially if they had to stay in the Intensive Care Unit while being treated as this will require the use of a ventilator. Apart from the cost that comes along with using the device, nobody likes an object being placed over their nose or mouth, or the idea of having difficulty with breathing. This article aims to illuminate why the iron lungs should be considered as a possible mechanical ventilation option for COVID-19 patients with breathing difficulties.
The iron lungs
Also known as “tank ventilator” or “drink tank” was invented in 1928 by Phillips Drink and Louis Shaw. It is a type of mechanical respirator that applies negative pressure and covers most of the body. However, it’s use has become outmoded as more sophisticated models have been manufactured and been in use. It’s used as a form of treatment was usually as a result of diseases like polio, and botulism as they could cause difficulty in breathing in severe cases.
How it works?
It has a large cylindrical shape, where the patient is laid with their head protruding out through a hole at the end of the cylinder. It applies negative pressure which is almost similar to the human breathing process, while the head is kept out to make sure the patient is exposed to ambient air, the rest of their body is enclosed in the cylinder where air pressure is continuously circulated, to encourage breathing.
During the process of inhalation, air is pumped out of the cylinder, resulting in a small vacuum, which then allows the patient to breath-in air through the exposed nose and mouth, causing the chest and abdomen to expand. To exhale, the air in the cylinder is allowed to level with the ambient room pressure, causing the chest and abdomen to slightly collapse, leading to the escape of air from the lungs to the exposed mouth and nose.
Why it is no longer in use
The development of modern ventilators, eradication of poliomyelitis in most countries, restriction of patient’s movement, and the difficulty in finding spare parts when there is a need for replacement are some of the reasons the use of the device became outdated in the field of medicine. As of 2014, there were only 10 known users of the iron lungs, with modern devices like tracheal intubation and tracheotomy taking over. To date, Paul Alexander, a US man is the only known user of the iron lungs.
It is also a form of mechanical ventilation that assist patients with breathing difficulty to breathe with the use of positive pressure. They are computerized devices, that are controlled by microprocessors, and are mainly used in intensive care units, anesthesiology, and emergency medicine.
Advantages of Iron lungs over modern ventilator
Iron lungs use negative pressure ventilation, which is very similar to human physiological breathing, thereby, resulting in more circulation of air in the lungs. It is usually a better option for patients with certain rare conditions such as central hyperventilation syndrome. It is cheaper to manufacture as compared to a modern ventilator.
COVID-19 pandemic and its use
Patients that manifest severe COVID-19 symptoms, often have difficulty with breathing, resulting in them needing mechanical ventilation. The scarcity and cost of modern ventilators led some initiatives into developing new prototypes of the iron lungs. Some of them included;
-a compact, torso-sized ‘exovent’ developed by a team in the UK.
-a full-sized iron lungs developed in the US by a team led by Hess service, Inc. of Hays, Kansas.
Though obsolete and restrictive, the cost of purchase and the likeness to human physiology are reasons for the use of iron lungs in bridging the gap created by the increasing demand for mechanical ventilation be considered. The ongoing global pandemic has created opportunities for the development of new versions which will possibly look into the few faults of the iron lungs to increase its availability, enable its usage, especially for countries struggling with the cost of a modern ventilator.