Science

Ventilators can heal but also harm

High grade: A ventilator has to be exactly calibrated or it can cause altered pressure changes.

High grade: A ventilator has to be exactly calibrated or it can cause altered pressure changes.   | Photo Credit: ARUN SANKAR

An evaluation is needed to assess what the patient needs

Ventilators are not easy to understand, this is true even for most doctors. Only a relatively small percentage of people who work in ICUs are able to disentangle, de-mystify and decipher these complex machines.

Now, we find ourselves on our knees before a disease that takes away our fundamental ability to draw breath. The seemingly logical solution appears to be the creation and use of more ventilators. Unfortunately, it is not that simple.

If the breathing process is compromised, it most often leads to the failure of every other organ system, making the ventilator the undisputed hero of the piece. A ventilator is able to force air into the lungs so that breathing in is no longer the person’s responsibility. This sounds deceptively simple.

The nose and the mouth draw in air. The windpipe or the trachea directs the air into passages called the bronchi. These tubes pass through our lungs and divide further into tiny bronchioles that end in balloon-shaped pockets called alveoli, of which the average human has about three million. Blood vessels called capillaries surround the alveoli. It is here that oxygen enters the bloodstream.

By simply drawing in air, we call into being a silent orchestral dance that can be felt if we place our palms upon our heaving chests. Even the best artificial ventilators fall far short of duplicating this rhythm and flow.

Safety factors

But even if the ventilator is not a completely refined one, isn’t it better than nothing? An artificial ventilator that is not exactly graded or calibrated can become a killing machine. The altered pressure changes can damage the lungs. Ventilators can only drive air into the lungs. They cannot fulfil the equally vital task of transferring oxygen into the blood, should the lungs be too damaged to do so.

In the present situation, first, everyone with a breathing difficulty from COVID-19 does not automatically require a ventilator. Second, they may not even be good candidates for ventilation because, in a large number of people with serious COVID-19, the lungs seem to be too badly damaged to recover. . Third, the general condition of the person determines whether there is a reasonable chance for him or her to come out of it alive and well. This is not to say that ventilation is not a viable option in some cases.

Chances of survival

Unfortunately, however, evidence thus far indicates that in general, the chances of survival after ventilation are not good. A published study based on the experience in 12 New York hospitals showed that only 11.9% of 320 patients survived, in whom ventilators were used and the treatment had come to a logical conclusion (discharge or death of the patient). That result spanned all age groups. In the elderly, particularly among those with specific associated diseases , the chances of survival are even poorer.

Symptoms and their experience vary widely across populations, and all this talk of ventilation is applicable only to the minority – those with severe infection, particularly, the elderly and those with other serious concurrent illnesses.

To understand what is best for a patient an evaluation is necessary. The process is called triage. It is recommended that the attending team and the triage team are separate from one another.

On May 19, the World Health Assembly passed a resolution that palliative care should be made available to all people with COVID19. This would mean being mindful of suffering irrespective of disease status and making a concentrated effort to alleviate it as far as possible. It would involve adequate treatment of pain as well as other distressing symptoms. This would be bolstered by appropriate emotional support. Honest information compassionately given forms the cornerstone of such practice.

Those with reasonable chances of survival are ear-marked to receive care in intensive care units with ventilators when necessary. Such ventilators should not be hastily put-together contraptions, but those that are able to mimic air flow in the lungs as near normal as possible. Enough sedation is given to them so that the ventilator is tolerated and stress minimised.

Those with next-to-no chances of survival and their families would be counselled about the gravity of the situation and assisted in making an informed choice whether to go for aggressive intensive care with a ventilator or to forgo it while continuing to receive comfort care with compassion.

Palliative care

By providing palliative care to those with COVID-19 we shall be reducing the quantum of suffering.

Following the advice of World Health Assembly to provide access to palliative care would necessitate basic online training to all doctors and nurses treating COVID-19, and access to essential palliative care drugs including controlled medicines. Will we square up to the task?

(The author is the Chairman of Pallium India and Director, Trivandrum Institute of Palliative Sciences )

Related Topics
Recommended for you
This article is closed for comments.
Please Email the Editor

Printable version | Jul 12, 2020 1:20:37 PM | https://www.thehindu.com/sci-tech/science/ventilators-can-heal-but-also-harm/article31768099.ece

Next Story