Caroline Sisson, MMS, PA-C: Updates in Pulmonary Function Testing

A 2021 update to guidelines for pulmonary function testing (PFTs) from the European Respiratory Society (ERS) and American Thoracic Society (ATS) helped to provide a modern approach to prioritizing measures including spirometry, lung volume and diffusing capacity.¹ As one expert explained, the uptake of new recommendations may still be slow—but there’s evidenced blueprints on how to adequately gauge lung function today.

In an interview with HCPLive during the American Academy of Physician Associates (AAPA) 2024 Conference & Expo in Houston, TX, this week, Caroline Sisson, MMS, PA-C, pulmonary physician assistant and department vice chair at the Wake Forest University School of Medicine, discussed the lag from her colleagues to fully adopt the 2021 ERS-ATS guidelines. One contributing issue to the matter is other organizations continuing with their own conflicting recommendations still.

“For example, the COPD GOLD guidelines still use present-predicted to assess severity of obstruction, which is not in line with what the ERS-ATS is using,” Sisson said. “So, there's some conflicting guidance out there, and I would want to talk about what the advantages and disadvantages are to those different sets of guidelines, and why that is.”

Sisson additionally highlighted the new guideline’s move away from race-based medicine’s involvement in spirometry interpretations—an outmoded practice that’s conflicted with evidence-based strategies for some time.

Regarding utility of PFTs, Sisson emphasized the value of contextualizing data results with available imagery of pulmonary function per the flow volume look mapped out by spirometry.

“I think that's kind of the lowest common denominator, is if we're looking at values to make something fit,” Sisson said. “But we can get a lot more information by looking at the picture and understanding like physiologically, why it looks the way that it does, and to put that in the context of a disease, in the context of a history and physical exam—or basically the patient's story—to come up with the right diagnosis.”

Indeed, Sisson advocated for continual contextualization of test results with one another: combining spirometry and lung volume results, or diffusing capacity of the lungs for carbon monoxide (DLC) to help depicts status of the alveolar membrane. These strategies can add color to a perceived black-and-white diagnostic strategy.

“How do I put together this whole picture, to get an understanding of how people's airways are behaving, of how well they're able to diffuse oxygen in the actual alveolar space—to put together the whole picture, because the reality is a lot of patients have more than 1 disease state happening at the same time,” Sisson explained. “When we know all of these different components, I can have a more holistic picture of what's going on and how I can best help them.”

Sisson additionally provided perspective on the impact of advancing targeted pulmonary therapies with regard to refined testing and monitoring, as well as the involvement of patient-reported outcomes relative to PFTs.

“I will say there are times where I do think we need to have discussions with patients about how aggressive do you want to be—do you want to keep doing this test, are you happy with where you are?” she said. “Because it's also an added cost to the patient. It's extra time if there's a different appointment that they have to go to.”

References

1. ^{Stanojevic S, Kaminsky DA, Miller MR, et al. ERS/ATS technical standard on interpretive strategies for routine lung function tests. Eur Respir J. 2022;60(1):2101499. Published 2022 Jul 13. doi:10.1183/13993003.01499-2021}