NASA scientists as well as other innovators are busy developing alternatives to the traditional ventilator being used worldwide to treat severe cases of Covid-19. The movement is in response to growing evidence that in some cases ventilators can cause more harm than good in some patients with low oxygen levels. Statistics tell the story: 80% of patients with the coronavirus die on such machines.
This comes just a few months since the early days of the coronavirus pandemic, when U.S. healthcare providers said that they needed ventilators to accommodate the flood of new patients, and lots of them. The crisis triggered the Trump administration to activate the Defense Production Act so manufacturers including Ford, GM and GE could start ventilator production to produce these medical devices for the U.S. government.Â
According to the healthcare news publication STAT, today's growing skepticism about ventilator use is driven by the fact that many of the coronavirus patients doctors treated had blood oxygen levels so low it should have killed them, but didn't. Since physicians have traditionally used blood oxygen levels to judge whether to put a patient on a ventilator, this usual phenomenon with Covid-19 patients, throws established protocols into question. Furthermore, it calls into question whether less invasive breathing support could be an effective option.
Sunny Jha, an anesthesiologist at the University of Southern California who also treats critically ill Covid-19 patients at the Los Angeles Surge Hospital, said that the way ventilators supply lungs with oxygen can actually cause damage to the lungs, in certain cases.
"This sort of stretching caused by air being pushed into the lung via the ventilator, versus being pulled into the lung in normal breathing, can cause damage, or barotrauma, to the lung cells, further worsening the lung damage from the virus," he said. "This builds up over time and can lead to a more rapid worsening of the lungs, if they do not start to get better on their own."
Turner Osler, MD, FACS, MSc. Emeritus Professor in the Department of Surgery at University of Vermont, said that in cases such as those, caregivers are faced with a dilemma, which he described as "a deal with the devil."
"The elevated ventilator settings required to support some Covid-19 patients can actually damage their lungs further," he said. "It buys time, putting off imminent death, but at the price of further damaging the lung."
He stressed that a ventilator is an emergency solution to a life-threatening problem, and in many cases is the "go-to" solution. However, he added that patients who are put on ventilators may have a long and difficult road ahead of them when it's time to get off of them.
"Getting a patient off a ventilator can require them to redevelop the strength needed to breathe," he said. "This can be a prolonged effort known in the [intensive care unit] as 'weaning,' a process that can take days, or even weeks."
Ventilator design 2.0
There are currently alternatives to the ventilator being tested, and some come from sectors of the economy not normally associated with health care, such as aerospace. NASA has designed its own ventilator prototype that has received FDA authorization for Covid-19 use. The machine's purpose is not to replace traditional mechanically-complex hospital ventilators, but to keep patients from needing one in the first place.
NASA's "Ventilator Intervention Technology Accessible Locally," or VITAL, is designed to be built faster and easier than a traditional ventilator, and with fewer parts. However, it is not made to last as long as typical hospital hardware — just three or four months compared to years for a more durable device. In addition, it is constructed with components from outside the medical device supply chain, according to the agency, to lessen the impact on the supplies needed for currently made ventilators. It's flexible design means it can be modified for field hospitals.
It also is tailored specifically for people with Covid-19, which helped to guide its design.
This new technology, designed by engineers at NASA's Jet Propulsion Laboratory in just 37 days, was tested at the Human Simulation Lab in the Department of Anesthesiology, Perioperative, and Pain Medicine at Mount Sinai Hospital in New York City, where Matthew Levin, M.D. gave it high marks. On Friday, it announced that it chose eight U.S. manufacturers to make the NASA ventilator including Stark Industries, Vacumed, ATRON and Evo Design.
"The NASA prototype performed as expected under a wide variety of simulated patient conditions," Levin said. "The team feels confident that the VITAL ventilator will be able to safely ventilate patients suffering from Covid-19 both here in the United States and throughout the world."
Because the machine is tailored for Covid-19 patients, it's focused on providing air delicately to stiff lungs — a hallmark symptom of the virus. Stiff lungs have a harder time expanding, so patients struggle to get enough air to breathe. VITAL is meant to provide enough air pressure to patients to inflate their lungs but not so much so that the lungs over-expand. The machine also works to ensure the lungs don't completely deflate, either.
Covid-19 patients have lung damage that makes the sides of their lungs inflamed and sticky. If all the air goes out of their lungs and the sides touch each other, they might stick together and make it even harder to open back up again. So VITAL tries to keep the lungs slightly inflated whenever patients exhale.
NASA isn't the only non-medical entity hoping to lend a hand during this crisis. Automaker Tesla had retrofitted some of its car parts to build ventilators, while Ford and General Motors had restructured their assembly lines to manufacture them. Additionally, the household appliance company Dyson had paused the manufacturing of vacuum cleaners to help create more ventilators.
Innovation on ventilator design is popping up around the country. Engineers at the University of Illinois developed a prototype for a simple emergency ventilator, called Rapid Vent, that would only cost $100 to $200 to make. Rapid Vent is a pressure-controlled ventilator that connects into the oxygen supply available in any regular hospital room. Air flows from the hospital oxygen supply into the ventilator and then into the patient's lungs through a tube or a mask.
At MIT, the MIT Emergency Ventilator Project, is dedicated to creating an open-source, low-cost ventilator, based on a project that was completed in a MIT engineering class back in 2010. Students made a ventilator prototype using less than $200 of materials, which is much cheaper than the typical ventilator that can cost as much as $30,000. Today, these materials would cost close to $400 or $500.
The MIT design utilizes an "Ambu bag," or a bag-valve resuscitator, which is a hand-operated resuscitator that's commonly found in hospitals. Health-care providers use these tools to manually pump artificial breaths into a person's lungs when they cannot breathe adequately or at all.
Therapy options for Covid-19
Apart from these new technologies that are being worked on right now and the tried and true methods that have been used for years, health-care providers already have other tools at their disposal in the fight against Covid-19, none of which require FDA approval. Sunny Jha of the University of Southern California said that simply having some patients lie on their bellies can help.
"Oftentimes, these non-invasive strategies are sufficient to overcome the damage done by the virus to provide enough supplemental oxygen for the patient to recover on their own," he said. He added that he believed a cure for Covid-19 is a long way off, so people should continue to use existing therapies until further notice.
"I don't think a magic bullet will happen in the short term, and people hoping that some cure or treatment will come around rapidly is a fool's hope," he said. "I don't think it's reasonable to expect the medical community to rapidly come up with a cure for a novel virus that we simply don't know much about yet."
Turner Osler of the University of Vermont added that even though traditional ventilators are not perfect, and new therapies are always welcome, patients will always need them, especially now.
"If a patient is unable to breathe, nothing short of a ventilator will succeed," Osler said. "Some temporizing measures are available, such as nasal oxygen supplementation and continuous positive airway pressure (CPAP), but none of these are a replacement for the ventilator. … For a patient in true ventilatory failure, a ventilator is really the only solution."
