What's the Link Between ARDS and COVID-19?

As of March 2022, the Centers for Disease Control and Prevention (CDC) states that most individuals who become infected with COVID-19 will experience mild symptoms. However, others may require hospitalization, and for some patients, COVID-19 can be deadly.

One life-threatening complication that can arise is acute respiratory distress syndrome, commonly referred to as ARDS. Research from a February 2021 study published in Scientific Reports listed ARDS as one of the risk factors for an increased probability of in-hospital death among COVID-19 patients.

What Exactly Is ARDS?

The American Lung Association (ALA) says ARDS is a rapidly progressive disease that can occur in critically ill patients—most notably, in those diagnosed with severe illness resulting from COVID-19.

"ARDS is manifested as rapid and progressive shortness of breath," Shervin Takyar, MD, PhD, a Yale Medicine pulmonologist, told Health. Per the ALA, along with severe shortness of breath, those with ARDS often have severe cough and fever. Fast heart rate and rapid breathing show up in patients with ARDS as well, along with chest pain, particularly during inhaling. Further, ARDS is sometimes initially diagnosed as pneumonia or pulmonary edema (fluid in the lungs from heart disease).

The disease can be caused by direct injuries to the lungs (pneumonia, aspiration, near drowning, or smoke inhalation) or indirect injuries (sepsis, blood transfusions, or medication reactions). Many people still won't develop ARDS even with those injuries. However, some risk factors according to the National Heart, Lung, and Blood Institute—like smoking history, air pollution exposure, and infections—can increase a person's risk of developing the disease.

How Is ARDS Treated and What Are the Complications?

In most cases of ARDS, patients will have to be supported by supplemental oxygen and mechanical ventilation soon after the start of their symptoms, said Dr. Takyar. When their blood oxygen levels remain low, patients may be flipped into a "prone" position to get more oxygen into their blood, says the ALA.

Proning is literally turning people over on their bellies, instead of having them on their back on a ventilator, Jeanne Marrazzo, MD, professor of medicine in the infectious diseases division at the University of Alabama at Birmingham, explained during an April 2020 media briefing sponsored by the Infectious Diseases Society of America. "And when you do that in a cycle, you get better oxygenation, and the outcomes are incredible," said Dr. Marrazzo.

In some cases, if inflammation and fluid in the lungs persist, some ARDS patients will develop scarring of the lungs (the fibrotic stage of ARDS). In others, the lung or lungs can eventually pop and deflate, leading to pneumothorax or a collapsed lung.

According to the American Thoracic Society, ARDS can be fatal for approximately 40% of those diagnosed with the disease—even with considerable treatment. In those who recover, lung function gradually improves over six months to a year, and even then, they're left with significant scarring and lower than normal lung volumes. Those who survive ARDS can also go on to suffer from anxiety, depression, and PTSD from the impaired quality of life and lung function, Gregory P. Cosgrove, MD, Vice President of Clinical Development at Pliant Therapeutics, told Health.

How Does COVID-19 Lead to ARDS?

Essentially, the connection between ARDS and COVID-19 concerns how COVID-19 affects a person's breathing.

Similar to many other viruses, coronaviruses—including SARS-CoV-2—can infect and damage the lung cells, setting the stage for the occurrence of ARDS, explained Dr. Takyar. "It is thought that the infection-induced damage and inflammation cause a malfunction of the lung vasculature [the pulmonary vessels within the lungs]," said Dr. Takyar. When that happens, the exchange of oxygen within the body is impaired. Among viruses, the ones that cause pneumonia (like COVID-19) are more likely to cause ARDS.

When patients are in the late stages of COVID-19 infection—after severe damage has already been done to their lungs—their body will try to fight off the virus by sending immune cells to the lungs, which is what ultimately causes the inflammatory reaction, explained Dr. Takyar. In fact, ARDS in COVID-19 "seems to be less directly due to the virus itself and more related to inflammation, or the body's response to the virus," added Jaimie Meyer, MD, a Yale Medicine infectious disease specialist.

The literature surrounding ARDS and COVID-19 has noted that the two often go hand-in-hand. Researchers from a March 2021 study in Nature Reviews Microbiology indicated that older COVID-19 patients who also had critical pre-existing medical issues were likely to develop ARDS. Another December 2021 study published in Pneumonia said that both lung failure and ARDS were the most prominent lung-related issues for COVID-19 patients.

Researchers additionally considered ARDS to be "a serious complication of COVID-19" in a January 2022 study from Viruses. They found that 3.6% of COVID-19 hospitalized patients ended up having ARDS, and 88.8% of those patients died from ARDS-related issues.

Even if you have one or more ARDS risk factors, getting a COVID-19 vaccine is one way to lower the chance of developing ARDS, as vaccination can prevent an increased severity level of a COVID-19 infection. Still, if you or someone who has contracted COVID-19 experiences breathing troubles, seek emergency medical attention right away.

The information in this story is accurate as of press time. However, as the situation surrounding COVID-19 continues to evolve, it's possible that some data have changed since publication. While Health is trying to keep our stories as up-to-date as possible, we also encourage readers to stay informed on news and recommendations for their own communities by using the CDC, WHO, and their local public health department as resources.