Medical Care: How ventilators work
Ventilator – Amidst COVID-19, the biggest concern of the medical industry is the lack of ventilators. This is a worldwide concern, which fuelled the #flattenthecurve movement. To flatten the curve means to lower the number of infections that occur at the same time. The fewer people infected simultaneously, the more ventilators, hospital beds and other resources will be available.
Ventilators are sometimes called “respirators”, although contemporary hospital and medical terminology now use the word “respirator” to refer to a protective face-mask.
Ventilators and respirator masks are important tools in the fight against the COVID-19 pandemic.
Most people who contract the COVID-19 disease will likely only experience mild symptoms, although reports say that about 6% of them will need hospital care, with older patients at higher risk.
Professor Sarath Ranganathan, a board member of Lung Foundation Australia and director of respiratory and sleep medicine at Melbourne’s The Royal Children’s Hospital, told The Guardian: “The experience in Italy and Spain, and the modelling used by mathematicians around the world, indicate that the number of people who will become critically ill with COVID-19 will greatly exceed the capacity to care for them using respiratory support.
“Without access to ventilators, many patients who might survive the infection will die.”
But what is a ventilator and what does it do?
A ventilator is a machine that assists the lungs.
Before COVID-19, respirators were used to assist patients with severe respiratory conditions that impact the lungs, including pneumonia.
Patients are given muscle relaxants to ease the intubation necessary to be put on a ventilator. The machine connects to the tube that has been inserted through the mouth and into the windpipe.
The ventilator feeds oxygen to the lungs, essentially assisting the patient’s breathing.
Prof David Story, deputy director of the University of Melbourne’s Centre for Integrated Critical Care, and a staff anaesthetist at Austin Hospital says that ventilation is needed when a patient’s breathing rate increases to 28 breaths a minute. A normal breathing rate is about 15 breaths a minute.
“The breathing rate will increase, they’ll look distressed, the CO2 in the blood goes up and they can become sedated and confused,” he says.
New-age ventilators are designed with a compressible air reservoir or turbine (pneumatically compressed several times a minute to deliver breathable air into the patient’s body) that supplies air and oxygen; it has a set of valves and tubes, and a disposable or reusable “patient circuit”, Wikipedia explains.
The materials used for the intubation and the many customisable ventilator settings are made to keep patients comfortable. Ventilators are only operated by trained staff such as respiratory therapists and nurses.
Certain modern ventilators also have alarm systems to signal medical staff to monitor patients’ parameters – pressure, volume and flow.
The alarm can also signal parameters of the device itself, such as a low battery charge and different aspects of mechanical failure like leakage.
The machines are maintained by biomedical technologists.
What does a ventilator cost?
The need for more ventilators has spurred exciting innovations, with many companies volunteering to assist in creating cost-effective versions.
How we made it SA reports that modern ventilators used in top hospitals cost anything from $20,000 and upwards.
The South African company EPCM Holdings has made news with its low-cost ventilator units for delivery to several African countries for around $2000 a unit.
EPCM’s co-founder and CEO, Tom Cowan, says: “At that stage, I wasn’t even 100% sure what a ventilator does. We talked about it and it was explained to me. It sounded like something very similar to a gas system that we usually design.”
He continues: “About two hours after that, the first concept of a ventilator was born, and maybe two hours after that we started with a more detailed design … And it took about two to three days for us to completely understand what we wanted to build and to make a few prototypes. “We’ve specifically designed it to be easy to manufacture … Our design can be made from Perspex; it can be made from stainless steel. If you have nothing else, you can even make it from wood.
“The whole idea behind this was to get it rapidly manufactured. We’ve partnered with a laser-cutting company in South Africa, which can cut many of the sheets in a day that we simply assemble.”
Designs for ventilators need European Union approval. There are many regulations and hurdles to get your ventilators certified.
How do ventilators assist in COVID-19?
Coronavirus patients experience difficulty breathing. The disease attacks the lungs and presents like very severe pneumonia.
Studies show that it damages the tiny air sacs (alveoli) in the lungs, choking off the body’s oxygen supply. This happens until it shuts down the organ completely. More recent studies have also shown that coronavirus affects the other organs too, including the kidneys and stomach.
Because trouble breathing is one of the deadlier symptoms of a more progressed stage of the virus, a shortage of ventilators can be devastating. In countries like Italy, the shortage of ventilators has left doctors in the harrowing position of having to decide which patients are more eligible. People over the age of 60 now no longer qualify to be put on ventilators to make way for the younger coronavirus sufferers.
What other types of long-term damage can coronavirus cause to the lungs?
COVID-19 can cause lung complications like pneumonia that fill the lungs with fluid.
Many people also recover from coronavirus and go on to develop acute respiratory distress syndrome (ARDS). This is a more progressed form of pneumonia and is classified as a type of lung failure.
Hopkins Medicine says that whether it occurs at home or at the hospital, ARDS can be fatal. People who survive ARDS and recover from COVID-19 may have lasting pulmonary scarring.
Sepsis from COVID-19 can also cause lasting harm to the lungs and other organs.