Coronavirus and ventilators


After self-isolating for seven days because he had the coronavirus, UK prime minister Boris Johnson has now been placed in an ICU of a London hospital, presumably because his symptoms have taken a turn for the worse. It is not clear if he has been placed on a ventilator. His spokespersons have been less than forthcoming about his condition in the past week, issuing upbeat statements when it now seems that he was not doing so well, and that has naturally made people suspect that things are worse than what they are being told.

We have heard a lot of talk recently of the need for ventilators to treat people with severe respiratory problems arising from the virus. I had been under the impression that this was a short-term treatment until they recovered and were able to breathe on their own and could be taken off the machines. But it turns out that once you are placed in a ventilator because of the coronavirus, the chances of recovering are not good.

Most coronavirus patients who end up on ventilators go on to die, according to several small studies from the U.S., China and Europe.

And many of the patients who continue to live can’t be taken off the mechanical breathing machines.

“It’s very concerning to see how many patients who require ventilation do not make it out of the hospital,” says Dr. Tiffany Osborn, a critical care specialist at Washington University in St. Louis who has been caring for coronavirus patients at Barnes-Jewish Hospital.

The largest study so far to look at mortality among coronavirus patients on ventilators was done by the Intensive Care National Audit & Research Centre in London. It found that among 98 ventilated patients in the U.K., just 33 were discharged alive.

The numbers from a study of Wuhan, China, are even grimmer. Only 3 of 22 ventilated patients survived.

And a study of 18 ventilated patients in Washington state found that nine were still alive when the study ended, but only six had recovered enough to breathe on their own.

All the early research suggests that once coronavirus patients are placed on a ventilator, they will probably need to stay on it for weeks. And the longer patients remain on a breathing machine, the more likely they are to die.

“We’re not sure how much help ventilators are going to be,” Osborn says. “They may help keep somebody alive in the short term. We’re not sure if it’s going to help keep someone alive in the long term.”

Those who still keep making the argument that the coronavirus is just like, or even not as bad as, the flu that kills many thousands each year seem to ignore the fact that ordinary flu, while it does kills many people, does not grow at anywhere near the exponential rate of this virus. It is this exponential growth that makes it alarming. Also, the pneumonia that kills many people that get the ordinary flu is of a different kind than the coronavirus-induced pneumonia, with the latter being more dangerous.

Ventilators have been seen as critical to treating coronavirus patients because the devices are very successful when used to treat common forms of pneumonia, says [Negin Hajizadeh, a pulmonary critical care doctor].

“We treat patients for several days, and then we get the antibiotics into the body and the patient recovers,” she says. “Unfortunately with this COVID-associated pneumonia, there are no treatments that we know work for sure.”

Also, the coronavirus often does a lot more damage to a person’s lungs than pneumonia associated with the flu. “There is fluid and other toxic chemicals, cytokines we call them, raging throughout the lung tissue,” she says.

In some patients, the damage is so bad that even ventilation won’t help. So doctors have sometimes tried an even more extreme measure called extracorporeal membrane oxygenation, or ECMO, which delivers oxygen directly to a patient’s bloodstream.

But this is still a stopgap measure. “Remember, ECMO too is a life-supporting treatment,” Hajizadeh says. “So it’s a bridge while we are allowing the lung to heal itself from a pneumonia.”

But lungs don’t always heal, no matter how much help they get from a machine, Osborn says. So people need to be diligent about social distancing to keep the virus from spreading.

This means that the chances are small that ventilators once assigned to someone will later free up to be used for anyone else, unless that person dies. So the demand for ventilators will keep going up and not stabilize as soon as we might have hoped. That is worrying.

Comments

  1. says

    I have a friend whose hobby is conspiracies. He thinks Xi Xinping may be dead from C19 caught when he went to Wuhan to show how well the government was handling things. Xi has been pretty quiet lately…

  2. Allison says

    Marcus Ranum @5:

    Tobacco smoke or any smoke?

    I am not a pulmonologist, but my understanding is that the nicotine damages the cillia in the lungs. Smoke is not good, but tobacco smoke is worse than generic smoke. I don’t know about meth or opium. As for vaping, I would guess that if it has nicotine, it would be almost as bad as tobacco cigarettes.

  3. says

    Allison@#6: interesting! Thanks.

    Meth is a big problem out here and I’ve long wondered if it’s carcinogenic. But you are right -- the nicotene is the toxin.

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