Beyond Spirometry : Linking Wasted Ventilation to Exertional Dyspnea in the Initial Stages of COPD

Exertional dyspnea, a key complaint of patients with chronic obstructive pulmonary disease (COPD), ultimately reflects an increased inspiratory neural drive to breathe. In non-hypoxemic patients with largely preserved lung mechanics - as those in the initial stages of the disease - the heightened inspiratory neural drive is strongly associated with an exaggerated ventilatory response to metabolic demand. Several lines of evidence indicate that the so-called excess ventilation (high ventilation-CO2 output relationship) primarily reflects poor gas exchange efficiency, namely increased physiological dead space. Pulmonary function tests estimating the extension of the wasted ventilation and selected cardiopulmonary exercise testing variables can, therefore, shed unique light on the genesis of patients' out-of-proportion dyspnea. After a succinct overview of the basis of gas exchange efficiency in health and inefficiency in COPD, we discuss how wasted ventilation translates into exertional dyspnea in individual patients. We then outline what is currently known about the structural basis of wasted ventilation in "minor/trivial" COPD vis-à-vis the contribution of emphysema versus a potential impairment in lung perfusion across non-emphysematous lung. After summarizing some unanswered questions on the field, we propose that functional imaging be amalgamated with pulmonary function tests beyond spirometry to improve our understanding of this deeply neglected cause of exertional dyspnea. Advances in the field will depend on our ability to develop robust platforms for deeply phenotyping (structurally and functionally), the dyspneic patients showing unordinary high wasted ventilation despite relatively preserved FEV1.

Medienart:

E-Artikel

Erscheinungsjahr:

2024

Erschienen:

2024

Enthalten in:

Zur Gesamtaufnahme - volume:21

Enthalten in:

COPD - 21(2024), 1 vom: 29. Feb., Seite 2301549

Sprache:

Englisch

Beteiligte Personen:

Neder, J Alberto [VerfasserIn]
Santyr, Giles [VerfasserIn]
Zanette, Brandon [VerfasserIn]
Kirby, Miranda [VerfasserIn]
Pourafkari, Marina [VerfasserIn]
James, Matthew D [VerfasserIn]
Vincent, Sandra G [VerfasserIn]
Ferguson, Carrie [VerfasserIn]
Wang, Chu-Yi [VerfasserIn]
Domnik, Nicolle J [VerfasserIn]
Phillips, Devin B [VerfasserIn]
Porszasz, Janos [VerfasserIn]
Stringer, William W [VerfasserIn]
O'Donnell, Denis E [VerfasserIn]

Links:

Volltext

Themen:

Blood flow
Dsypnea
Emphysema
Gas exchange
Journal Article
Mild COPD
Review

Anmerkungen:

Date Completed 14.02.2024

Date Revised 14.02.2024

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1080/15412555.2023.2301549

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM368389707