Coronavirus: Ventilators, Explained By Milwaukee Respiratory Experts

Apr 9, 2020

State officials say there are about 1,200 ventilators across Wisconsin and the state has plans to acquire  as many as 10,000 more. The aim is to provide breathing assistance for some patients with serious COVID-19 symptoms.

This week, it was even announced that the Foxconn corporation may start making the machines at its manufacturing facility being built in Racine County.

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Here's how ventilators work: They pump a mixture of air and oxygen to a patient’s lungs through a tube into the windpipe, or through a facial mask. The machine also helps remove carbon dioxide from the body.

Dwayne Schlund heads the respiratory therapy program at Milwaukee Area Technical College. He says ventilators, or as he calls them vents, vary.

“Right now, we’re using every vent possible. But ideally, we’d want critical care type of vents because they have more modes and more settings to be able to treat these patients with COVID-19. Because some of them have very sick lungs, we need all the bells and whistles we can get,” Schlund told WUWM.

Schlund says it’s not just the oxygen mix that needs controlling. Other factors include the pressure of the air going in, the patient’s breathing rate, and air volume.

MATC ventilators being prepped to loan to Milwaukee-area hospitals during the coronavirus pandemic.
Credit Courtesy of Dwayne Schlund

He says health care teams help decide the right settings, but a respiratory therapist manages the machine hour by hour.

“It is intense, but that is what they’re trained to do," Schlund said. "Every single respiratory therapist that is trained, is trained in critical care. They all go into the ICU as students to train, and they all work in the ICU once they’ve graduated.’’

MATC recently loaned a few ventilators to area hospitals, including Froedtert, where Dr. Thomas Carver is the medical director of the Surgical Intensive Care Unit. Carver says the machines have long been used for patients undergoing surgery or in intensive care for diseases like pneumonia. 

With infections like COVID-19, he says the lungs become inflamed.

“And when they get inflamed, they don’t work as well. And in fact, the body can’t compensate anymore. You can breathe only so fast. You can only pull in so much oxygen,” Carver said.

Carver cautions that ventilators do not save every COVID-19 patient.

“One, your low oxygen levels can lead to problems. But also, the body’s response to the virus can lead to problems and that can cause kidney failure. It can cause the heart to stop working, and people can develop multiple organ system failure, and that’s primarily why people die,” Carver explained.

Despite the limits on the effectiveness of mechanical ventilators, Madison.com reported this week that “a group of state doctors and bioethicists is preparing guidelines for which patients should get ventilators if there aren’t enough for everyone” during the expected COVID-19 peak later this month.

During this pandemic, WUWM's Bubbler Talk is focusing on the coronavirus and its impact on the Milwaukee area. If you have a question, submit it below.

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