Abstract
Background: Dynamic hyperinflation (DH) is a key mechanism related with dyspnea and exercise intolerance in COPD patients. Quantitative computed tomography (CT) measurements strongly correlate with physiologic measurements of airway obstruction; however nothing is known about its relationship with physiological assessment of DH.
Aims: Compare the effects of metronome-paced hyperventilation (MPH) on lung volumes evaluated by spirometry and CT densitovolumetry (CTd) in patients with moderate COPD (50%≤FEV1<80%pred).
Methods: 16 patients with COPD (60.7±10.7 yr; FEV<sub style="text-align: justify;">1= 70±7% pred) after a 1-wk wash-out period using only short acting BD as rescue medication performed spirometry and CTd before and after MPH (respiratory rate twice the baseline rate for 30s).
Results: Patients ranged from normal to slightly/moderately hyperinflated at rest (TLC: 109±14; FRC: 121±24; and RV: 125±36 % predicted). After MPH, inspiratory capacity (IC) significantly reduced, indicating DH. Nevertheless, CTd measurements did not change significantly
.
Conclusions: In the present sample, quantitative CT measurements were insensitive to detect DH in patients with moderate COPD.
- © 2014 ERS