Ventilators are a critical tool in the fight against COVID-19. Here’s what you need to know about them

Two main things about the COVID-19 pandemic terrify Dr. John Granton, head of respirology at University Health Network.

One, he says, is running out of personal protective equipment. The other is having to face a surge of patients "like we saw in New York. Italy was terrifying."

But early evidence suggests the spread of COVID-19 in Toronto is slowing due to public health measures and the virus isn't playing out the way the first models predicted, relying initially on data from China and Italy, as well as other countries where the pandemic hit early.

That means questions about who would get a ventilator, if they were ever in short supply, haven't had to be answered.

As of Friday, April 17, 128 patients in Toronto hospitals had been intubated since the outbreak began. The city has 344 ventilators, according to a report from Critical Care Services Ontario from April 8 listing the number in each of the province's 14 Local Health Integrated Networks. More of the machines have been ordered by the federal government.

A third of COVID-19 patients who have been intubated since the start of the outbreak are 70 or older.

"I think what we're seeing is the benefit of the public health policy we put in place," Granton says. "I think many of us were panicked in the health-care system when this wasn't happening because we knew what was coming based on other countries," he says.

"So what we've seen is a flattening of this curve," says Granton. "So far, I think, we have been able to delay or defer a rise in the number of a cases. Because if we didn't do that, then we would have experienced what happened in Europe and also in New York."

Patients with COVID-19 who go on ventilators have a 20 to 30 per cent survival rate, he says.

Here's more on our conversation with Granton about the medical devices that people are talking less about at this stage in the pandemic but remain a crucial tool in the fight to save lives. This interview has been edited for clarity and length.

What do ventilators look like?

Ventilators can be small - about the size of a bread box - like the ones used by a person with sleep apnea, or larger, which are the ones we have in intensive care. They typically have a screen similar to a small television set with different touch controls to set the machine and also to give you an output of what's going on with the patient.

How does a ventilator work?

Doctors prescribe how fast and how big a breath a patient should receive and set the machine accordingly. Sometimes, when the machine is sophisticated enough, a patient can initiate the breath and the machine responds by giving them different levels of pressure. The actual business part of the machine is the system which provides a breath through a hose that is attached to the patient. Once the breath is delivered, the patient exhales through a different port through the ventilator. The air is filtered so that no one in the room is exposed to the breath from the patient.

Why are some ventilators only the size of a suitcase?

The machines can be simple or very complex. It's like a car, really. You can buy a bare-bones car, that doesn't have a lot of bells and whistles, or you can buy one that's got a lot of different features associated with it. But for the most part, I think in response to the pandemic, people are getting the ones that are easier to build but will do the job, as opposed to a whole bunch of fancy machines where a lot of those different measurements or different features may not be needed.

What does the ventilator do for patients who have the virus?

They're not a treatment for anything. They're merely a way of cradling the person until such time that their body recovers. So for example if you went for surgery, you would be given an anesthetic, intubated, put on a breathing machine and then you would have your operation. The anesthetic would be stopped, you'd gradually wake up, and then you'd have the tube taken out.

But when you're critically ill, you're intubated and then you remain on the machine until such time that your breathing goes back to normal or the condition for which you were intubated resolves. And then the tube is eventually taken out.

Why do some COVID-19 patients need ventilation?

You can't generally get enough oxygen in and/or you can't get enough carbon dioxide out of your blood system because the lungs aren't working efficiently anymore because of the damage from the virus.

Why are patients intubated - putting a tube in their airway - as opposed to delivering air through a non-invasive method such as a mask?

That is mainly because of the risk of spread to health-care workers when we're using a non- invasive method, such as a mask. More of the virus is aerosolized when using non-invasive ventilation because of leaks in the system, which means we can't isolate the room or the health-care workers from the spread of the virus. So most centres in Canada, and I think in North America, aren't using non-invasive ventilation.

Why was Italy able to use non-invasive helmets to ventilate some patients with the virus? (The helmets go over a patient's head and are sealed with an airtight collar around the neck.)

A lot of the work around non-invasive ventilation comes from some major centres in Europe, and particularly in Italy and France. Europe is perhaps much more finessed in non-invasive ventilation. They used it as a strategy to limit the number of people they had to intubate. We could consider that if we surged to that level. That was something that was on deck if things really got dire, is that we would consider using less sophisticated ventilators to provide potentially non-invasive ventilation through a face mask or nasal mask, to avoid intubation.

Is that easier on a patient?

If you wait until a person gets really sick it can be challenging to get an airway into someone safely. It can be better to be pre-emptive and get a tube in earlier. However, I think in general we view the ability to keep people from being intubated better because they require less sedation. And that's a good thing because they can mobilize and move around and stay a bit stronger. When you intubate them, there's an immediate effect on their system and they have to be sedated and some of the learnings from our centre, and others, is that they can get some lung damage and breathing muscle damage just from the effect of the breathing machine. In fact, that's one of the major areas of research, trying to reduce the damage that was caused by ventilators in the past. So the delicate balance is providing support to the patient but not to the point that we're causing lung damage.

Why do only 30 per cent of patients survive after being ventilated?

The problem with that is it's a nasty virus. Not everybody who gets COVID gets sick, but if you get sick enough to have to go on a breathing machine then your chances of survival are less. The death rates (once on a ventilator) range from 20 to 30 per cent depending on who you read. That's not unusual. There are thousands of deaths from flu every year and some of the people do die on ventilators. It's not that the ventilators aren't working, it's just that their system is so severely damaged that the disease outstrips the ability of the machines to provide them enough support.

Would you ever turn away a person because of their age?

It's more than age. Age comes with a lot of unfortunate baggage. But there is a clear relationship between survival and age. It's not being ageist. It's just being factual. Research shows that if you're over the age of 50 you're not going to do as well as someone under the age of 50, accounting for everything. If you're older, you'll have less chance of survival and the quality of life and the life after being extremely ill is not as good as if you're under the age of 50. So then you mark it up to 80 and that become even worse. That's the problem.

How do you decide if an older patient is put on a ventilator?

I think it's just having a conversation with the patient hopefully, and the family. Often it's about setting expectations of what the chances of recovery are. And the quality of what life would look like if you did recover and what it would involve. People don't just suddenly wake up and feel great again. They have a very prolonged period of recovery and a lot of stresses, not only physical but psychological after a critical illness. It is singularly life-altering.

So it's a long recovery period?

It can be years. If you're critically ill, to the point of showing up here and having to go on intense levels of treatment, even young people can have significant degrees of disability both mental and physical. From any disease. If you wind up critically ill on a ventilator with severe infection or severe illness and you're in ICU for over a week, it's very challenging.

The federal government is still calling on companies to make more ventilators. Do you think we need them? There's a lot of discussion on how important testing is. Do we need swabs more than we need ventilators?

I don't think it's that we need one more than the other. This is a new world. I think we need to be prepared. I think we need to be able to respond to what we're facing right now. I still think people feel it's an unknown. I've said before it may be difficult to predict tornadoes but you'll only be faulted for not being able to respond to them. I think we can't predict these pandemics but you'd only be faulted if you weren't in a place to respond.

Patty Winsa is a Toronto-based data reporter. Reach her via email: pwinsa@thestar.ca