When Asthma and COPD Intersect

Though pure asthma and pure emphysema or chronic obstructive pulmonary disorder (COPD) are more common, sometimes the conditions overlap, says Marianne Frieri, M.D., Ph.D.

The root of both conditions is inflammation. “In emphysema, it’s more the smaller airways we call the alveoli, and in asthma it’s more the upper bronchial airways,” Frieri says. “But even in asthma, the small airways can be affected.”

A pulmonologist could help distinguish between the conditions, as could spirometry, Frieri says.

Though the treatments for COPD, emphysema and asthma are fundamentally different, the medications are often the same. An inhaled steroid and a bronchodilator combination, such as Advair, is commonly used to treat both, Frieri says.

Even though the medications are similar, the responses might be different. “If we measure an asthmatic before and after a bronchodilator, we expect to see a 15-20 percent increase in what they’re getting out in one second,” says Carol Proctor, RRT, RPFT, AE-C. “We may not see that with emphysema, but that doesn’t mean the patient is not getting the benefit from that. The emphysema is considered fixed, irreversible, whereas the asthma is a reversible process.”

When someone has overlapping asthma and COPD, using oxygen might complicate treatment. “That’s one more thing that’s going down into your nose that can transmit bacteria that you have to be careful with,” Proctor explains. “It dries the airways, and if you dry the airways, then you’re leaving them more open to things.”

Proctor says that the rapid cooling and drying of the airways can cause bronchospasm. “If we’re cooling their airways with oxygen, we can create a twitch right there for somebody that’s already sensitive.”

Education for patients with an overlapping condition is more intensive than in asthma alone. Proctor says she goes into how emphysema destroys the surface that absorbs oxygen and the associated capillary beds.

“If you look at a model of the airways for asthma and for chronic obstructive pulmonary disease, there are a lot of similarities,” Proctor says. “There’s swelling, there’s mucus, sometimes this twitch of the muscles in the airways. In addition, with emphysema because of the hyperaeration and the hyperinflation generally in the apical areas, there’s a distortion of airways, much like a Chinese finger torture, where they’ve been sort of pulled out of place and narrowed. So, you have that narrowing in addition to any narrowing because of inflammation or mucus or bronchospasm.”

This article originally appeared in the Respiratory Management April 2008 issue of HME Business.

About the Author

Elisha Bury is the editor of Respiratory Management.

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