Photo credit: John Minchillo/AP

Every day, the number of positive confirmed coronavirus cases rise, and the urgent call for ventilators increases.

There is perhaps no voice louder than New York Governor Andrew Cuomo. Thursday, he repeated the call for help.

"Ventilators, ventilators, ventilators," he said. "I didn't know what they were a few weeks ago, besides the cursory knowledge. I know too much about ventilators now. We're still shopping for ventilators all across the country. We need more."

About 25 percent of hospitalized COVID-19 patients in China needed beds in intensive care units. Which means they needed ventilators. The figures are about the same in New York. Louisiana, another area overwhelmed by the vicious SARS-CoV-2 virus, has needed ventilators for about 35 percent of their critically ill patients.

These machines are so crucial because of what the virus does to the lungs. Ventilators do not cure COVID-19. They take over the breathing process, giving the body time to build up defenses to fight against the virus.

Many COVID-19 patients who require ICU care, have pneumonia or other complications due to the virus, one of the more common and deadly is ARDS – acute respiratory distress syndrome.

Dr. Adam Keene is a critical care medicine and infectious disease doctor at Montefiore Hospital in the Bronx. He says the ARDS they are seeing in COVID-19 patients is unique.

"We sort of had some previews from the descriptions from China, from South Korea and from Washington,"said Keene. "This appears to be somewhat less predictable, where patients can be, seeming to be doing relatively well, maybe just needing some oxygen, through your nose or through a mask on your face, to suddenly requiring a ventilator to keep them alive."

ARDS is an inflammatory reaction oftentimes, to an infection in the lungs.

"With this COVID disease, your lung units get filled up with fluid, and you get very sick and can't deliver oxygen to your brain or other organs," said Keene.

Another issue with COVID-19 patients is they tend to need much more time on the ventilators.

"There are some disease processes that we can put you on a ventilator, get you through it and take you off quite quickly, in a day or two. But for most patients with COVID-related disease, if they need a ventilator and are going to survive, it seems like it's taking weeks or more," said Keene. "That's a problem because those are ventilators that can't be freed up. So it puts additional demands on the need for ventilators."

Governor Andrew Cuomo said Thursday ICU patients in New York have needed ventilators for 11 to 21 days.

The fluid that builds up in the lungs of COVID-19 patients deflates the alveoli, those tiny sacs that handle the gas exchange. The ventilators are crucial not only for supplying oxygen, but also because they can administer something called PEEP, positive end-expiratory pressure, which essentially props the lungs open, allowing for the exchange of oxygen and carbon dioxide.

Another method that has been found to keep critically ill COVID-19 patients alive is something called proning, where medical staff turn the patient over onto their bellies once or twice a day.

"The lung units are filled with both infected and inflammatory liquid that tends to, in most patients, be more pronounced in the back and the bottom parts of the lungs. And if it stays in that region for long periods of time, it just gets worse and worse. So when we turn a patient over, when we prone them, it's redistributing that fluid to other areas of the lungs," said Keene. "That's a very labor-intensive, particularly nursing-intensive process. It takes three to five people, well-trained to do that process. There's always some risks involved in doing it. So, you know, and it means that every time we go in, we have to gown up completely with our PPE. So it's sort of a PPE-intensive process as well."

As the nation grapples with a shortage of ventilators, New York State is prepared to experiment with splitting one ventilator between two patients, something that is only ever done in dire situations. Keene says it is not ideal for COVID-19 patients.

"I think that in the past, this has been used in very limited scenarios like in mass trauma events where you run out of ventilators very quickly and there has been some success with it. It's quite complicated and very labor intensive to take care of two patients on one ventilator because, unless their lungs are exactly the same and they're in exactly the same clinical settings, they may need some different settings," said Keene.

It could though be an option for non-COVID-19 patients also in need of intensive care. 

"When we get to the point, which we seem to be reaching, where we're running out of ventilators, we could potentially use it on other patients with other disease processes," said Keene. Like two patients who may need ventilators after a stroke, but are not being treated primarily for lung injury.

While hospitals in heavily affected areas like New York are making the necessary space for more beds, Keene says ventilators are the most crucial piece of equipment needed in this pandemic, other than protective gear, which limits the spread of the virus.

"We may have a bed available for a patient at one of these expanded rooms, but not have a ventilator to keep them alive," said Keene. "That's a horrible thing and something that certainly in the U.S. I don't think most practitioners have faced. In less developed countries, this happens all the time. But it's something that sort of always was thought would be unacceptable in the United States, although we knew that there would always be a potential for something like this to happen."