To Ventilate or Not to Ventilate? Taking Your Covid-19 Questions.

As the coronavirus pandemic continues to spread, Undark readers have been sending us numerous and often insightful questions, comments, and observations on the subject. We’ve asked the Pulitzer Prize-winning science journalist and Undark’s publisher, Deborah Blum, to dedicate some time to responding — both as a reader service, and as another way for Undark to cast some light into the darkness of misinformation, rumor, fear, and conjecture now percolating through the information commons.

You can find previous iterations of this feature here. And if you have questions, comments, or would like to see some other aspect of the Covid-19 crisis explored in a subsequent feature, please write us at: [email protected]. (Reader questions and comments below have been edited and sometimes combined for clarity and brevity.)

If only 14 percent of ventilator patients live — and if most all of those folks will have significant complications (i.e., lung damage), maybe somebody needs to rethink the routine use of ventilators? Also: Is the focus on ventilators pulling precious resources away from other Covid-19 containment tactics that might reduce infections in the first place — like increased tracking and quarantining, for example?”

These are both smart and also ethically tricky questions.

While increasingly expensive, it’s important to start with the fact that ventilators are often last-chance life-savers for people whose lungs are catastrophically failing them. They are considered so vital in such cases that much of the ethical debate thus far has focused on equipment shortages and triage decisions. And yet, it’s true that survival patterns for Covid-19 patients put on ventilators and other such machines are not encouraging. One detailed report out of the U.K. did find a somewhat more encouraging survival rate — about 34 percent. But some of the results out of China, as noted, are less hopeful, suggesting a survival rate of only 14 percent.

That’s not necessarily surprising. Clinical studies over the years have consistently found that if patients are sick enough to require a ventilator, their odds of survival are already comparatively low. “People with true ARDS, (Acute Respiratory Distress Syndrome), be it caused by flu or Covid-19 or other causes, are really, really sick,” said Howard Markel, a physician and medical historian, at the University of Michigan, in an email interview. “And even if put on a ventilator and treated by expert intensive care, many have serious underlying conditions that topple them into the grave.”

And of course, any intensive treatment can cause lasting harm to surviving patients, both psychological and physical — including lung damage from ventilators. This does have some physicians more seriously discussing other, less invasive ways, to provide oxygen to Covid-19 patients.

Whether this constellation of factors warrants a rethinking of ventilator use as a medical strategy, however, is a dicey question — and to some, an offensive one. Jeremy Faust, an emergency room physician at Brigham and Women’s Hospital in Boston and an instructor in the health policy program there, for example, says ventilators absolutely ought to remain a fundamental tool in preventing Covid-19 deaths — particularly if we believe that even the very sick deserve the chance to fight. “It’s actually shocking to me that people would propose abandoning a routine treatment that saves lives merely 14 percent of the time,” he wrote in an email message, noting that the number is likely higher than that.

Sure, some critically ill people can pull through without being intubated, Faust said. But many — or most — will not, and he finds the idea of denying those people even a chance to survive, however slim, “perplexing, at best.”

And in any case, Markel suggested that any tendency to frame Covid-19 treatments and interventions as a matter of either-or — that is, we can do this, or that, but not both — reflects one of the basic failures of American healthy policy. “In Washington,” he said, “every funding debate runs the risk of becoming a zero sum game — so if you fund the respirator lane, the vaccine lane, or the flattening the curve lane, or the contact tracing lanes suffer.”

“What we clearly need,” Markel said, “is a well-planned, comprehensive omnibus plan for all these critical avenues, rather than fighting over them in the heat of battle.”

What about less expensive and complicated designs for ventilators? Could these not be built in much less time and for far less cost?

It’s true that standard ventilators are costing up to $50,000 apiece these days, given dismaying shortages of the machines. A host of inventors, companies, and even hospitals themselves are now stepping up to that challenge. Among the options are one developed by Mercedes engineers and another smaller, more efficient machine from the Dyson company (maker of hand dryers and vacuum cleaners).

Universities, ranging from big institutions like MIT to smaller ones like Indiana’s Trine University, are also taking on the problem. In fact, so many people have started to pursue alternate machines that some doctors are starting to sound wary of the home-made possibilities coming their way: “We don’t want to put something like a DIY, Home Depot version in a hospital,” one physician told Time magazine, “and see how many patients it can kill.”

I’d like to know about more contact tracing and what it can actually uncover in terms of knowledge. So far, I see little evidence of anything but fleeting tracing to identify possibly infected people.

When it’s done right, contact tracing — the process of identifying people who may have come into contact with an infected person, and then gathering as much information as possible about those interactions — provides public health officials with a detailed roadmap of viral spread and a plan for how to best isolate and limit it. Ideally, epidemiologists hunt for the very first sick person — sometimes called “patient zero” or the “index patient.” In China, where SARS-CoV-2 originated, health officials confirmed a first case report on November 17, 2019. That patient was apparently a vendor at a meat market in Wuhan.

As point of comparison, on March 5 in the state of Tennessee, a patient zero was identified as a pharmaceutical employee who had attended a meeting in Boston hosted by the company Biogen. That meeting turned out to be what’s called a super-spreader event, infecting a large number of people. And this is where contact tracing becomes particularly useful: In the Biogen case, health officials tried to find every person who attended the meeting, trace their subsequent contacts and connections, test for infection, and isolate people where indicated.

The problem is that the effectiveness of contact tracing is largely dependent on other factors, including being able to test people for Covid-19. While some small communities in the U.S., including New Rochelle, New York, have experienced successful contact tracing efforts, shortages of test kits have been a national problem from the start, and continue to be an issue even today. It’s also important in any contact tracing effort for the public to receive clear and accurate information about the effectiveness of self-isolating. As we know, months of mixed and sometimes incorrect messaging from national leadership has helped to stymie effective mitigation efforts, even leading some sick people to resist isolation.

These failures have caused problems from Washington state to Georgia. But in countries like Germany and South Korea, contract tracing — complete with clear public messaging and plentiful test kits — has proved a very effective tool for controlling the spread of SARS-CoV-2.

I am interested to know if my cat at home could possibly get coronavirus from me, asymptomatic or not, after reading about the Malayan tiger case in the Bronx zoo?

The short and I hope reassuring answer is: probably not. Although, it was definitely attention-grabbing when the Bronx Zoo reported this week that one of its tigers had tested positive for Covid-19, and that several other big cats — including some lions — were symptomatic. Researchers think the big cats caught the virus from an infected human handler, and they say several issues are important to consider as a result.

In the same way that humans are vulnerable to milder coronaviruses that cause colds, cats also are known to catch a mild strain called feline coronavirus or FCoV, which may have been a factor in the illness at the zoo. There is also some evidence from China that cats can infect each other.

But to date there is no evidence suggesting that people can catch Covid-19 from, nor pass the illness on to, their pet cats. Thousands of pet owners around the world have contracted the virus, while so far, there is no evidence that their thousands of domestic cats followed them into infection. This has led some scientists to speculate that some big cats, such as tigers, may be more prone to catching the infection — though even here, if the Bronx Zoo is a good example, their illness looks so far fairly mild.

That’s it for this installment, but if questions or observations occur to you as this pandemic moves forward, don’t hesitate to contact us. We’ll do our best to include your input or otherwise provide you with realistic answers — and we can promise you they’ll be well researched ones. Please email us at [email protected].

Deborah Blum is the director of the Knight Science Journalism Fellowship Program at MIT and the publisher of Undark.