Even as hospitals and governors raise the alarm about a shortage of ventilators, some critical care physicians are questioning the widespread use of the breathing machines for Covid-19 patients, saying that large numbers of patients could instead be treated with less intensive respiratory support.
If the iconoclasts are right, putting coronavirus patients on ventilators could be of little benefit to many and even harmful to some.
What’s driving this reassessment is a baffling observation about Covid-19: Many patients have blood oxygen levels so low they should be dead. But they’re not gasping for air, their hearts aren’t racing, and their brains show no signs of blinking off from lack of oxygen.
That is making critical care physicians suspect that blood levels of oxygen, which for decades have driven decisions about breathing support for patients with pneumonia and acute respiratory distress, might be misleading them about how to care for those with Covid-19. In particular, more and more are concerned about the use of intubation and mechanical ventilators. They argue that more patients could receive simpler, noninvasive respiratory support, such as the breathing masks used in sleep apnea, at least to start with and maybe for the duration of the illness.
“I think we may indeed be able to support a subset of these patients” with less invasive breathing support, said Sohan Japa, an internal medicine physician at Boston’s Brigham and Women’s Hospital. “I think we have to be more nuanced about who we intubate.”
That would help relieve a shortage of ventilators so critical that states are scrambling to procure them and some hospitals are taking the unprecedented (and largely untested) step of using a single ventilator for more than one patient. And it would mean fewer Covid-19 patients, particularly elderly ones, would be at risk of suffering the long-term cognitive and physical effects of sedation and intubation while being on a ventilator.
None of this means that ventilators are not necessary in the Covid-19 crisis, or that hospitals are wrong to fear running out. But as doctors learn more about treating Covid-19, and question old dogma about blood oxygen and the need for ventilators, they might be able to substitute simpler and more widely available devices.
An oxygen saturation rate below 93% (normal is 95% to 100%) has long been taken as a sign of potential hypoxia and impending organ damage. Before Covid-19, when the oxygen level dropped below this threshold, physicians supported their patients’ breathing with noninvasive devices such as continuous positive airway pressure (CPAP, the sleep apnea device) and bilevel positive airway pressure ventilators (BiPAP). Both work via a tube into a face mask.
In severe pneumonia or acute respiratory distress unrelated to Covid-19, or if the noninvasive devices don’t boost oxygen levels enough, critical care doctors turn to mechanical ventilators that push oxygen into the lungs at a preset rate and force: A physician threads a 10-inch plastic tube down a patient’s throat and into the lungs, attaches it to the ventilator, and administers heavy and long-lasting sedation so the patient can’t fight the sensation of being unable to breathe on his own.
But because in some patients with Covid-19, blood-oxygen levels fall to hardly-ever-seen levels, into the 70s and even lower, physicians are intubating them sooner. “Data from China suggested that early intubation would keep Covid-19 patients’ heart, liver, and kidneys from failing due to hypoxia,” said a veteran emergency medicine physician. “This has been the whole thing driving decisions about breathing support: Knock them out and put them on a ventilator.”
To be sure, many physicians are starting simple. “Most hospitals, including ours, are using simpler, noninvasive strategies first,” including the apnea devices and even nasal cannulas, said Greg Martin, a critical care physician at Emory University School of Medicine and president-elect of the Society of Critical Care Medicine. (Nasal cannulas are tubes whose two prongs, held beneath the nostrils by elastic, deliver air to the nose.) “It doesn’t require sedation and the patient [remains conscious and] can participate in his care. But if the oxygen saturation gets too low you can achieve more oxygen delivery with a mechanical ventilator.”
The question is whether ICU physicians are moving patients to mechanical ventilators too quickly. “Almost the entire decision tree is driven by oxygen saturation levels,” said the emergency medicine physician, who asked not to be named so as not to appear to be criticizing colleagues.
That’s not unreasonable. In patients who are on ventilators due to non-Covid-19 pneumonia or acute respiratory distress, a blood oxygen level in the 80s can mean impending death, with no room to give noninvasive breathing support more time to work. Physicians are using their experience with ventilators in those situations to guide their care for Covid-19 patients. The problem, critical care physician Cameron Kyle-Sidell told Medscape this week, is that because U.S. physicians had never seen Covid-19 before February, they are basing clinical decisions on conditions that may not be good guides.
“It’s hard to switch tracks when the train is going a million miles an hour,” said Kyle-Sidell, who works at a New York City hospital. “This may be an entirely new disease,” making ventilator protocols developed for other conditions less than ideal.
As doctors learn more about the disease, however, both frontline experience and a few small studies are leading him and others to question how, and how often, mechanical ventilators are used for Covid-19.
The first batch of evidence relates to how often the machines fail to help. “Contrary to the impression that if extremely ill patients with Covid-19 are treated with ventilators they will live and if they are not, they will die, the reality is far different,” said geriatric and palliative care physician Muriel Gillick of Harvard Medical School.
Researchers in Wuhan, for instance, reported that, of 37 critically ill Covid-19 patients who were put on mechanical ventilators, 30 died within a month. In a U.S. study of patients in Seattle, only one of the seven patients older than 70 who were put on a ventilator survived; just 36% of those younger than 70 did. And in a study published by JAMA on Monday, physicians in Italy reported that nearly 90% of 1,300 critically ill patients with Covid-19 were intubated and put on a ventilator; only 11% received noninvasive ventilation. One-quarter died in the ICU; 58% were still in the ICU, and 16% had been discharged.
Older patients who do survive risk permanent cognitive and respiratory damage from being on heavy sedation for many days if not weeks and from the intubation, Gillick said.
To be sure, the mere need for ventilators in Covid-19 patients suggests many in the studies were so critically ill their chances of survival were poor no matter what care they received.
But one of the most severe consequences of Covid-19 suggests another reason the ventilators aren’t more beneficial. In acute respiratory distress syndrome, which results from immune cells ravaging the lungs and kills many Covid-19 patients, the air sacs of the lungs become filled with a gummy yellow fluid. “That limits oxygen transfer from the lungs to the blood even when a machine pumps in oxygen,” Gillick said.
As patients go downhill, protocols developed for other respiratory conditions call for increasing the force with which a ventilator delivers oxygen, the amount of oxygen, or the rate of delivery, she explained. But if oxygen can’t cross into the blood from the lungs in the first place, those measures, especially greater force, may prove harmful. High levels of oxygen impair the lung’s air sacs, while high pressure to force in more oxygen damages the lungs.
In a letter last week in the American Journal of Respiratory and Critical Care Medicine, researchers in Germany and Italy said their Covid-19 patients were unlike any others with acute respiratory distress. Their lungs are relatively elastic (“compliant”), a sign of health “in sharp contrast to expectations for severe ARDS.” Their low blood oxygen might result from things that ventilators don’t fix. Such patients need “the lowest possible [air pressure] and gentle ventilation,” they said, arguing against increasing the pressure even if blood oxygen levels remain low. “We need to be patient.”
“We need to ask, are we using ventilators in a way that makes sense for other diseases but not for this one?” Gillick said. “Instead of asking how do we ration a scarce resource, we should be asking how do we best treat this disease?”
Researchers and clinicians on the front lines are trying. In a small study last week in Annals of Intensive Care, physicians who treated Covid-19 patients at two hospitals in China found that the majority of patients needed no more than a nasal cannula. Among the 41% who needed more intense breathing support, none was put on a ventilator right away. Instead, they were given noninvasive devices such as BiPAP; their blood oxygen levels “significantly improved” after an hour or two. (Eventually two of seven needed to be intubated.) The researchers concluded that the more comfortable nasal cannula is just as good as BiPAP and that a middle ground is as safe for Covid-19 patients as quicker use of a ventilator.
“Anecdotal experience from Italy [also suggests] that they were able to support a number of folks using these [non-invasive] methods,” Japa said.
To be “more nuanced about who we intubate,” as she suggests, starts with questioning the significance of oxygen saturation levels. Those levels often “look beyond awful,” said Scott Weingart, a critical care physician in New York and host of the “EMCrit” podcast. But many can speak in full sentences, don’t report shortness of breath, and have no signs of the heart or other organ abnormalities that hypoxia can cause.
“The patients in front of me are unlike any I’ve ever seen,” Kyle-Sidell told Medscape about those he cared for in a hard-hit Brooklyn hospital. “They looked a lot more like they had altitude sickness than pneumonia.”
Because U.S. data on treating Covid-19 patients are nearly nonexistent, health care workers are flying blind when it comes to caring for such confounding patients. But anecdotally, Weingart said, “we’ve had a number of people who improved and got off CPAP or high flow [nasal cannulas] who would have been tubed 100 out of 100 times in the past.” What he calls “this knee-jerk response” of putting people on ventilators if their blood oxygen levels remain low with noninvasive devices “is really bad. … I think these patients do much, much worse on the ventilator.”
That could be because the ones who get intubated are the sickest, he said, “but that has not been my experience: It makes things worse as a direct result of the intubation.” High levels of force and oxygen levels, both in quest of restoring oxygen saturation levels to normal, can injure the lungs. “I would do everything in my power to avoid intubating patients,” Weingart said.
One reason Covid-19 patients can have near-hypoxic levels of blood oxygen without the usual gasping and other signs of impairment is that their blood levels of carbon dioxide, which diffuses into air in the lungs and is then exhaled, remain low. That suggests the lungs are still accomplishing the critical job of removing carbon dioxide even if they’re struggling to absorb oxygen. That, too, is reminiscent of altitude sickness more than pneumonia.
The noninvasive devices “can provide some amount of support for breathing and oxygenation, without needing a ventilator,” said ICU physician and pulmonologist Lakshman Swamy of Boston Medical Center.
One problem, though, is that CPAP and other positive-pressure machines pose a risk to health care workers, he said. The devices push aerosolized virus particles into the air, where anyone entering the patient’s room can inhale them. The intubation required for mechanical ventilators can also aerosolize virus particles, but the machine is a contained system after that.
“If we had unlimited supply of protective equipment and if we had a better understanding of what this virus actually does in terms of aerosolizing, and if we had more negative pressure rooms, then we would be able to use more” of the noninvasive breathing support devices, Swamy said.
To summarize the latest published research that we all read :
It seems that *COVID 19* doesnt cause pneumonia or ARDs and that may be we are treating a presumed wrong disease !!
* *SARS2* Corona Virus looks to bind hemoglobin in a certain way that releases the *iron* ion into the circulation
* *Hb* looses its capacity to bind with oxygen thus oxygen is not supplied to major organs. Which is why we see resistant hypoxia coupled with very rapid multi-organ failures.
* To simplify it more, we can take the example of CO-poison where Hb is unable to carry oxygen.
* The free *iron* released into the circulation is so toxic as it causes a powerful *oxidative damage* to the lungs (which may explain the bilateral -and always bilateral- ground glass opacities seen on Chest CT of those patients, that was mistakenly treated as bilateral pneumonia)
* The body try to compensate by elevating the rate of Hb synthesis which explains why HB is high in those patients that leads to increase in their blood viscosity .
* Other compensatory mechanisms to deal with the iron load such as increasing *ferritin* level explain the very high ferritin observed in those patients .
* *Chloroquine* as antimalarial drugs is working by protecting HB against invasion by malaria parasites .. it is doing the same here but just protecting the Hb against invasion by the virus
* This theory could explain why we are loosing patients so rapidly and why mechanical ventilation is not so much effective in treatment and using ARDS mechanical ventilation protocol is not causing any benefit. actually it could be futile and causing more lung damage
This also could explain
* why the high *ferritin* is bad prognostic marker (too much iron means too much Hb lost its O2 carrying capacity)
* Why there is *monocytosis* as the body needs excess macrophages to engulf the excess iron load .. Also why there is *Lymphopenia* as the WBCs differentiation is favored twards monocytes line rather than lymphocytes line.
* Why *liver* injury with high *ALT* level happens and why it carries a worse prognosis
The latest trials showed that patients also benefited from using anticoagulants , this comes in favor with the possibility of the presence of pulmonary micro emboli that is indicated by the presence of the D-dimer
* Sure more research is needed to understand the exact pathogenesis because this is the only hope for proper treatment .. You can not treat what you do not actually know.
I’m not an MD, not even close. But I am curious about the extra iron load mentioned above. Are anemic Covid-19 patients (or patients who normally have less available iron in the blood in general – like women of childbearing age) showing less damage in their lungs? Are Covid-19 patients who have some sort of iron overload co-morbidity experiencing more damage?
You hit the nail on the head please share your knowledge with the all the doctors and the world health organization to save lives.
CPAPS will aerosolize covid particles so you better have protection throughout the unit for both their eyes and mouth for your staff if you take this route. This includes anyone who is going on the unit. The people at the Opensource Covid project have tossed around this idea and last I checked, it had been canned.
Letter to the Editor: I am writing a response to this article “With ventilators running out, doctors say the machines are overused for Covid-19” by Sharon Begley for Stat News. While I believe panic is not necessary at this point, preparedness is. There is no denying that as of this moment ventilators are the only final attempt we can make to save someone suffering from COVID-19. It has also saved lives. The cases are increasing exponentially and if health professionals believe we need them, we should supply them with the things they request. This goal is not unattainable as the president has the ability to use his emergency powers to dramatically ramp up the production of ventilators. Ventilators don’t expire, so even if they are not used during this crisis they will be used eventually. In the meantime, we’ll be saving lives.
If ventilators don’t expire then why did NYC auction off it’s stockpile because they were outdated?
Thank you for this important articule. My mother 78 years old, she has been taken out of the ventilator yesterday and seen to be recuperating. I Really appreciate for this important articule.
This is great. Makes so much sense. Patience and not knee jerk ventilation. With every new disease we are learning more. Blessings on everyone on the front lines.
As a Registered Respiratory Therapist on Long Island, I find some of the statements in this article extremely inaccurate! Respiratory Therapists are the people involved with 90-95% of the intubations not physicians. In some hospitals they won’t even enter the room of a suspected cover patient. Let the record show!!
I agree. A lot of misinformation
As a layman, old enough to be in a higher risk category, I very much appreciate this article. If getting put on the ventilator is not going to work in 80% of cases and i am very likely to end up with long term health problems if I survive, including brain problems, I think, depending on my health and age, I should know that so I can turn it down. It sounds like it is not a good idea for a lot of people – you can not tell just by age, plenty of 80 year olds seem to be in pretty good shape – but if you have already significantly declined and have no reasonable expectation of coming out the other end in good shape….
I thank the author and Stat for the article.
Seriously, you’re questioning the “accepted rule” of using ventilators on a patient in the middle of pandemic that you know nothing about? What is the base of your question to begin with? All of this is new so there is no data and you can’t experiment on dying people base on your hunch. This is the kind of garbage science that make people think scientist are just trickster…
Seriously, why do people constantly question everything outside the norm? I troubleshoot for a living (multiple degrees in engineering) and if I thought like you do, the systems would be down for weeks. This doctor (and he is a doctor, unlike all the “who is this guy to question doctors?” crap you usually see (despite my own experience with medical doctors being extremely poor; they aren’t all A students and they don’t all know WTF they’re talking about outside their own specialty and general doctors know even less), this guy is TELLING YOU that the ventilators are killing 8/10 people on average.
You’ll argue it’s the virus, but he’s saying it is NOT and I believe him 100% more than YOU who know nothing. This “Pandemic” term is overused as well. Every cold and flu virus in the world is technically a “Pandemic”. You think we should follow “X” procedure no matter the results??? REALLY? Keep repeating “A” when it doesn’t work (and worse yet 80%+ of the patients die when you do it which are TERRIBLE odds). That’s the definition of crazy, BTW, doing something over and over and expecting a different result that never happens. If oxygen masks work better (notice they gave Boris Johnson oxygen and didn’t jump for the ventilator), then they should use them and use the ventilator only as a last resort as he said. And people like you should not comment as you are obviously ignorant.
You wrote: “And in a study published by JAMA on Monday, physicians in Italy reported that nearly 90% of 1,300 critically ill patients with Covid-19 were intubated and put on a ventilator; only 11% received noninvasive ventilation. One-quarter died in the ICU; 58% were still in the ICU, and 16% had been discharged.” That is not exactly correct, please check the report again.
Why did the census programs amended the census 1973-1979 other years also but that years mostly . Co v 19 is about what area mostly in Arizona State . I been reading up on it…and prisons need so much help also. …and in area called projects 19 . And has been a secret for many years . 19 area in Arizona State..I noticed all these federal government and agencies Indians are lying for many years so has Mexico. ..sad cause idiots that lie so much…
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