Explained | Covid's lasting damage to the lungs

More than three years after the start of the pandemic, many Covid-19 survivors continue to struggle. Some, especially those who became so severely ill that they were hospitalized and unable to breathe on their own, face lasting lung damage.

To better understand the long-term impact of Covid's assault on the lungs, The New York Times spoke with three patients who were hospitalized during the pandemic’s early waves, interviewed doctors who treated them and reviewed CT scans of their lungs over time.

One patient spent time connected to a ventilator; the other two were so debilitated that they required months on a heart-lung bypass machine called ECMO. These patients were not yet vaccinated — for two, vaccines weren’t available, and the third had planned to get vaccinated but was infected before he could.

The Times analyzed hundreds of millions of data points from the patients’ scans to reconstruct their lungs in 3D. The resulting visualization offers a vivid, visceral picture of damage that can linger years after infection and irrevocably alter everyday life.

Andy Muñoz, 36, of La Porte, Texas, was a welding inspector who enjoyed kayak fishing before he contracted Covid in July 2021. He spent more than six months on an ECMO machine.

“These lungs are not capable of sustaining life” is how Dr. Howard Huang, who treated Muñoz at Houston Methodist Hospital, described a lung scan taken six weeks after Muñoz was infected. “You look at this and you wonder: Is this ever going to get better?”

A second scan, taken two months later, showed slight improvement, and the lungs appeared closer to normal size. “It’s not shriveled up as much,” Huang said.

Sixteen months after his infection, Muñoz’s lungs had recovered somewhat, but not completely.

For some patients, the lung damage was less extreme but still left its mark. Tom Kennedy, 59, a lawyer for an industrial services company, was hospitalized with Covid in November 2020.

Kennedy, who lives in Houston, was hospitalized for about 80 days. He was in intensive care for about a month and on a ventilator for about 15 days. “I remember doing everything I could to draw one more breath,” he said.

Marlene Rodríguez was 34 weeks pregnant when she contracted Covid in December 2020. Her water broke 10 days later, and doctors delivered a healthy baby by C-section. But Rodríguez’s condition worsened.

Unable to breathe, Rodríguez required two months on ECMO. She developed a pneumothorax — air trapped between the lung and chest wall — on each side. The air needed to be drained to prevent lung collapse.

“She was maximally sick,” said Dr. David Sayah, who treated her at UCLA Medical Center. Once home, Rodríguez, 32, of Atwater, California, required supplemental oxygen for 14 months, but hasn’t needed it since.

Two and a half years after her infection, Rodríguez can accomplish most daily activities, but she becomes breathless and wheezes when she carries her toddler daughter or does chores such as mopping the floor. She uses an albuterol inhaler for tiring tasks such as climbing stairs.

“She doesn’t have a lot of lung to give,” Sayah said. “She’s certainly at risk for ending up in more trouble if she does have additional respiratory issues in the future.”

Many patients who experienced such severe lung damage early in the pandemic did not recover. Many died from a combination of direct injury by the virus and storms of inflammation incited by the immune system’s attempts to battle the infection. These three patients have been able to regain lung function to varying degrees, but the differences in their experiences reflect how unpredictable Covid's impact can be.

Effects vary by how healthy people were before infection and how their immune systems responded to the virus. Rodríguez has come closer to recovering, most likely helped by her youth and previous good health.

Kennedy was overweight, had diabetes and had suffered a heart attack six weeks before his infection, factors that increased his risk for a serious outcome.

“Had I taken better care of my health before Covid,” he said, “Covid would probably have not done to me what it did.”

Muñoz was very healthy and had intended to get vaccinated, but had not managed to do so before becoming infected in the summer of 2021. Huang said that because Muñoz’s immune system was not primed by a vaccine to recognize the invading virus, it most likely reacted overzealously, causing an inflammation surge that made his illness worse.

All three patients were listed as candidates for lung transplants, an option doctors hope to avoid because patients require immunosuppressive drugs and often die within five to 10 years after transplant. Now, doctors say Kennedy and Rodríguez probably won’t need transplants, but Muñoz may need one eventually.

In some ways, these patients have made better progress than doctors would have predicted. “We’re seeing examples where people do improve, even though they started out with a terrible-looking CT,” Huang said. But they’re unlikely to recover fully. “I don’t think anybody gets off completely scot-free if they’re that sick with Covid,” he said.

In addition to lung scans, doctors use several measures to evaluate respiratory function. A six-minute walk test evaluates patients’ cardiovascular health and fitness, tracking the distance patients walk and the way their lungs and heart respond. In March 2022, Muñoz walked 656 feet, slightly more than one-tenth of a mile, in six minutes. A year later, he walked over 1,443 feet.

Kennedy’s six-minute walk distance had increased to 2,024 feet in April, from 1,489 feet in May 2021. But his oxygen levels still dipped after walking for several minutes in the April test.

Another measure is called forced vital capacity, which is the volume of air a person can exhale after taking a deep breath. Although all three patients have gradually improved on this measure, none have returned to the normal range of 80 per cent of total lung capacity.

Muñoz’s forced vital capacity has increased to about 43 per cent from 29 per cent. Kennedy’s has increased to 59 per cent from about 38 per cent. Rodríguez’s has increased to 55 per cent from 39 per cent.

These numbers, and even the most detailed lung scans, tell only part of the story of infection and recovery. Muñoz’s girlfriend, Melissa Raymundo, said that early on, medical staff indicated that his chances of survival were low and discussed with her the possibility of letting him die. “Nobody thought he was going to make it,” she said.

Muñoz missed months with his two young sons. He remembers saying good night to them in a call from the hospital just before being connected to ECMO. “I woke up three months later,” he said.

During those months, doctors kept him heavily sedated so he wouldn’t move and disrupt the lifesaving machine. It took months longer to wean him from the sedatives and for his lungs to become strong enough to breathe on their own.

Nearly two years after his infection, he cannot work and needs round-the-clock oxygen at home. He has developed pulmonary high blood pressure, a serious condition of high blood pressure in blood vessels leading from the heart to the lungs.

“Breathing is still pretty hard,” he said. “But I’m home, I’m with my boys.”

“Most important, you’re alive,” Raymundo said.

Kennedy choked back tears as he recounted being in the hospital.

“I remember telling my wife to tell my children that I loved them,” he said. And he recalled being on the ventilator while his wife, Gayle, read aloud from one of his favorite books, “The Screwtape Letters.” While hospitalized, he experienced delirium, hallucinating that he had been kidnapped.

He has gradually returned to his job as general counsel of USA DeBusk, which provides services for oil and chemical companies. He works from home because he is continually tethered to a bulky oxygen machine with tubing that he calls “this leash that tugs at my nose.”

He said, “I don’t like it one bit, but it’s a lot better than where I thought I was headed.” Over time, the amount of oxygen he needs has diminished and, with a portable tank, he can play golf.

“I get tired, I feel bad a lot, but that’s just my new normal,” Kennedy said. He feels grateful.

“Whatever is the final stage before you die, that’s where I was,” he said. “But now I’m just in the group that deals with people that have really bad lungs.”

Rodríguez didn’t meet her newborn daughter, Vianney, until she was removed from the ECMO machine, 2 1/2 months after the baby was born.

She briefly returned to work as a receptionist at a plant nursery, but after getting laid off and trying another job, she and her husband, José, who has a chronic medical condition, decided, for health and financial reasons, to move in with his parents. Now, she spends her days caring for her three young children.

“I don’t feel the same as how I used to,” she said. She becomes winded when lifting heavy items or doing vigorous activities, and a second COVID infection recently has increased her fatigue and shortness of breath. She has experienced back pain and takes anxiety medication.

Still, it’s “one of the most remarkable recoveries,” Sayah said. “I don’t mean to imply that she’s recovered normal lung function, but when the expectation was that this person would for sure die without a lung transplant, to go from death to living at home without supplemental oxygen is a huge sort of success.”

Today, with coronavirus vaccines, antiviral treatments and other developments, doctors say they encounter few patients who are so severely afflicted. But they worry about those who wrestle with COVID’s enduring effects.

“People think that it’s kind of a one-and-done thing, like you can get over it like a common cold,” Huang said. “We’re left with a population of people like this that are kind of in this limbo state.”

This article originally appeared in The New York Times.