Most coronavirus patients who go on ventilators won't survive. But those who do can face long-term trauma.

• For the sickest COVID-19 patients, getting on a ventilator to help them breathe can be a life-saving process.
• The machines require sedation, and prevent patients from moving, communicating, or going to the bathroom on their own.
• Some patients who survive can experience longer-term physical complications including from organ failure that came up while the patient was on a ventilator, delirium, and, in COVID-19, the potential for long-term lung damage.
• Often, patients find the lasting mental-health toll from facing death and feeling helpless can be the most bothersome and difficult-to-treat consequence.
• Visit Business Insider's homepage for more stories.

When Rebecca Trahan heard New York Gov. Andrew Cuomo mention ventilators as the state was looking to increase its supply, she started to panic.

Trahan, 57, a creative director who lives in Harlem, knows what it's like to be on a ventilator, a machine used to help people breathe in times when they can't fully on their own.

"It's all coming back to me," Trahan told Business Insider.

In 2011, Trahan underwent triple bypass surgery after a spontaneous coronary artery dissection. When she woke up from surgery, she was on a ventilator. The experience was disorienting. She couldn't speak, she was strapped down, she didn't know what time it was, and she wasn't sure what would come next.

She didn't know if she was getting better. She didn't know if she'd always be living on a ventilator, a reality she wasn't interested in.

When the ventilator was removed a few days later, she was groggy and the room she was in felt different than before. "Nothing really made sense," Trahan said.

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Trahan's experience is one that many more people are set to face as they come off the breathing machines used in severe cases of COVID-19, the disease caused by the novel coronavirus. And while they are the lucky ones — most patients with COVID-19 who are put on ventilators don't survive — the experience can leave physical, and especially emotional, scars.

Once on a ventilator, patients can't communicate or move

A ventilator is a medical devices that essentially takes over a patient's breathing in "a very specific way," Dr. Burton Bentley II, CEO of Elite Medical Experts, previously told Insider.

Being put on a ventilator requires healthcare professionals to sedate the patient and insert a tube in their airway that connects to a machine. The machine then pushes air into the lungs and removes it.

The machines are used "when people lose their own ability to have normal respiration, they are too fatigued, or their lungs are impaired because they're full of fluid, or they can't in their own power oxygenate themselves at an effective level," Bentley said.

Once on a ventilator, patients can't communicate or move around, and thus can't perform basic daily functions like eating and going to the bathroom on their own.

Sometimes, patients' lungs resist the machine, and they have to be put in a medically induced coma.

The Associated Press reported in April that New York City officials said 80% of patients on ventilators there had died. "The longer you are on a ventilator, the less likely that you will ever come off that ventilator," Cuomo said in an April briefing.

Surviving time on a ventilator sometimes leads to complications, and lung function might not fully recover in COVID-19 patients

The complications associated with coming off a ventilator can differ based on how long a patient was on the machine.

Patients with severe cases of COVID-19 can also experience failures of other organs, such as their kidneys, and these can have long-term consequences. [ok?]

"Coming off a ventilator is the beginning of the end," Dr. Patrick Maher, a pulmonary medicine doctor with Mount Sinai who's been treating COVID-19 patients in the hospital's intensive care units, told Business Insider.

The heavy doses of sedation and blood pressure medications used to keep patients stable on the ventilators as their lungs recover can come with side effects. One is delirium, doctors told Business Insider in April. It's not easy to be sedated for that long.

After getting off the ventilator, patients won't go home right away. They might stay in the ICU for a few days more, then be transferred elsewhere in the hospital first.

How long it takes COVID-19 patients to get back to fully functioning on their own, Maher said, depends on how sick patients were and what their health was like before coming down with COVID-19.

Lung function in COVID-19 patients with severe forms of the illness might not recover completely, Business Insider's Morgan McFall-Johnsen previously reported.

In Trahan's case, she was able to come off the ventilator and started working to recover as fast as possible from her heart surgery. Soon, the marathoner was back to running.

Being on a ventilator can lead to long-term mood and cognitive changes

The weight of Trahan's emotional experience being on the ventilator — facing life-or-death questions, having something else breathe for her and not being able to talk — didn't hit her until her body had recovered, she said. Doctors and friends couldn't understand, assuming that because she had recovered physically, she was completely fine.

But, she remembered thinking, "I'm having trouble living," she said.

Dr. Craig Weinert, a pulmonologist and critical-care physician at the University of Minnesota who's studied mental health outcomes of ICU patients, told Business Insider that it's common for ventilator patients to find the psychological effects are more pronounced than the physical ones — and to be surprised by that.

"What they don't understand is all the other stuff that comes with it," including general physical weakness, brain fog, and poor mood — a cluster of symptoms researchers have dubbed post-intensive care syndrome, or PICS.

The syndrome can be especially common among patients on ventilators since the treatment, by nature, means they were near death.

"It really cements in people's minds: You know what? I could have died," Weinert said.

The experience can also be psychologically damaging because "your whole world shrinks down to your bed," he said. You can't talk, feed yourself, or go the bathroom on you're own; you don't know day from night; and you're surrounded by professionals whose presence reminds you that you could die at any moment.

Plus, the sedation medications can have their own long-term mental-health effects, although it's still not clear to doctors and researchers if or how they should adjust doses to help prevent those.

Experiencing symptoms of PICS is upsetting to patients not only because they're unexpected, but also because unless it reaches the point of a diagnosable mental illness, like depression, anxiety, or post-traumatic stress disorder, there's no clear treatment. And, Weinert said, it can lasts for months or even a lifetime.

For Trahan, being on a ventilator is haunting her now since she lives in one of the centers of the coronavirus pandemic. She's having an especially hard time not leaving her apartment to volunteer and help her community. But Trahan lives with heart failure, which puts her at high risk for severe illness caused by the COVID-19 virus.

"This would be something tough for me to survive," Trahan said.