There is no medical justification for exempting respiratory patients from compulsory face mask regulations, and doing so places this already vulnerable population at greater risk for COVID-19, a global group of pulmonary specialists said.

Beginning in May, the Spanish government mandated face masks in open- and closed-space public places, but the mandate exempted people with respiratory problems, “or those who cannot wear masks for other health reasons.”

Weighing in on this and other medical exemptions for respiratory patients, a European Respiratory Society (ERS) committee concluded that there is no evidence that masks harm anyone, including those with asthma, chronic obstructive pulmonary disease (COPD), or other respiratory diseases.

“It must be strongly stated that such exemption is not evidence based, and it may carry increased risk of personal infection to the estimated 544.9 million people worldwide suffering a chronic respiratory disease,” Joan Soriano, MD, PhD, of Madrid’s Hospital La Princesa, and colleagues wrote in a European Respiratory Journal research letter.

A new study from the U.S., appearing in the Annals of the American Thoracic Society, appears to bolster the ERS group’s conclusion.

When Michael Campos, MD, of the University of Miami and Miami VA Medical Center, and colleagues examined exhaled carbon dioxide levels in healthy volunteers and patients with COPD, they found little difference in exhaled CO₂ when masks were and were not worn.

Among COPD patients with severe disease performing routine 6-minute walk (6MW) tests to assess their need for supplemental oxygen, wearing a surgical mask was not associated with greater CO₂ retention or other significant changes in gas exchange.

Campos told MedPage Today that the political debate surrounding mask mandates led to his research.

“I watched a West Palm Beach hearing where people were claiming masks kill people and telling the council it was a crime against humanity to mandate masks,” he said, “I thought to myself, ‘There must be data showing this is not true.\'”

But a search of the literature turned up little, other than a few studies showing prolonged use of N95 masks to be associated with elevated exhaled CO₂ levels.

His study involved 15 healthy volunteer physicians without lung conditions (median age 31.3 years, 60% men) and 15 U.S. veterans with severe COPD (median age 71.6, FEV₁ 44.0% ± 22.2%, all men). Baseline measures on room air without a mask were performed followed by continuous monitoring when the participants were wearing a mask. This was followed by 6MW tests while wearing surgical masks.

Among the COPD patients at 5 and 30 minutes, no clinically significant changes in end-tidal CO₂ and oxygen saturation were observed at any point in the at-rest measures. During the 6MW tests, oxygenation decreased “as expected” and two participants needed oxygen, but the gas exchange measures on average didn’t show “major” changes. In particular, there was no important effect on CO₂ retention, the group said.

Campos told MedPage Today that, while he would not recommend the use of N95 masks for patients with respiratory disease, the use of surgical masks or cloth masks with at least two layers of cloth should be encouraged.

“It is especially important that people with respiratory diseases wear a mask because if these people get COVID they can get into real trouble,” he said.

The ERS writing group noted that while masks have been shown to protect against COVID-19, they are not the only intervention needed to stop the pandemic.

“The second waves [of COVID-19] being experienced globally, despite widespread masking, confirm masks are insufficient interventions,” they wrote. “With all likelihood, it is about a large number of issues, not just masks.”

While not perfect, mask use has been shown to be an important component in the effort to reduce infection and minimize “societal and economic disruption,” they wrote, adding that having asthma, COPD, and other chronic respiratory diseases should not impede mask use “unless the person is in active acute respiratory distress, in which case going out in public is not advised.”

“It is crucial for patients with respiratory conditions to wear face masks when they are in public spaces where social distancing cannot be applied easily,” they concluded.