Static and dynamic hyperinflation during severe acute exacerbations of chronic obstructive pulmonary disease

Abstract

Background

Static hyperinflation is known to be increased during moderate acute exacerbations of chronic obstructive pulmonary disease (COPD) (AECOPD), but few data exist in patients with severe exacerbations of COPD. The role of dynamic hyperinflation during exacerbations is unclear.

Methods

In a prospective, observational cohort study, we recruited patients admitted to hospital for AECOPD. The following measurements were performed upon admission and again after resolution (stable state) at least 42 days later: inspiratory capacity (IC), body plethysmography, dynamic hyperinflation by metronome-paced IC measurement, health-related quality of life and dyspnea.

Results

Forty COPD patients were included of whom 28 attended follow-up. The IC was low at admission (2.05±0.11 L) and increased again during resolution by 15.6%±23.1% or 0.28±0.08 L (mean ± standard error of the mean, p<0.01). Testing of metronome-paced changes in IC was feasible, and it decreased by 0.74±0.06 L at admission, similarly to at stable state. Clinical COPD Questionnaire score was 3.7±0.2 at admission and improved by 1.7±0.2 points (p<0.01), and the Borg dyspnea score improved by 2.2±0.5 points from 4.4±0.4 at admission (p<0.01).

Conclusion

Static hyperinflation is increased during severe AECOPD requiring hospitalization compared with stable state. We could measure metronome-paced dynamic hyperinflation during severe AECOPD but found no increase.

Keywords:

• COPD
• exacerbations of COPD
• static hyperinflation
• dynamic hyperinflation
• severe acute exacerbations of COPD
• COPD exacerbation
• chronic obstructive pulmonary disease

Acknowledgments

We thank Jantien Remmelink, Margot Klijnsma and Alice Niemeijer for the collection of data and for performing measurements. We thank Joost van den Aardweg for his support with some of the calculations. We would like to thank our complete pulmonary function team, especially Marga Star-Kroesen, Martijn Farenhorst, Margrietha Swieringavan der Veen, Yvonne Valkema-Tol, Wies Heins-Konigers and Jenny Stevens-van der Vinne for their time, flexibility and dedication to perform and schedule the pulmonary function tests during the study.

Disclosure

WHVG reports a grant for an investigator-initiated trial to University Medical Center Groningen from Novartis and an ERS short-term research fellowship, outside the submitted work. HAMK reports that his institution (University Medical Center Groningen) has received a fee per patient for recruitment in trials and a grant for investigator-initiated studies from GlaxoSmithKline, Novartis, and FLUIDDA. Additionally, his institution has received grants as well as consultancy fees from Novartis, AstraZeneca, Boehringer Ingelheim, and GlaxoSmithKline, all outside the submitted work. The authors report no other conflicts of interest in this work.