Pulmonary function impairment in patients with combined pulmonary fibrosis and emphysema with and without airflow obstruction

Abstract

BackgroundThe syndrome of combined pulmonary fibrosis and emphysema (CPFE) is a recently described entity associating upper-lobe emphysema and lower-lobe fibrosis. We sought to evaluate differences in pulmonary function between CPFE patients with and without airflow obstruction.Subjects and methodsThirty-one CPFE patients were divided into two groups according to the presence or absence of irreversible airflow obstruction based on spirometry (forced expiratory volume in 1 second/forced vital capacity <70% following inhalation of a β2-agonist) as follows: CPFE patients with airflow obstruction (CPFE OB+ group, n=11), and CPFE patients without airflow obstruction (CPFE OB− group, n=20). Pulmonary function, including respiratory impedance evaluated using impulse oscillometry and dynamic hyperinflation following metronome-paced incremental hyperventilation, was retrospectively analyzed in comparison with that observed in 49 chronic obstructive pulmonary disease (COPD) patients (n=49).ResultsIn imaging findings, low-attenuation-area scores on chest high-resolution computed tomography, representing the degree of emphysema, were significantly lower in the CPFE OB− group than in the CPFE OB+ and COPD groups. In contrast, the severity of pulmonary fibrosis was greater in the CPFE OB− group than in the CPFE OB+ group. In pulmonary function, lung hyperinflation was not apparent in the CPFE OB− group. Impairment of diffusion capacity was severe in both the CPFE OB− and CPFE OB+ groups. Impulse oscillometry showed that respiratory resistance was not apparent in the CPFE OB− group compared with the COPD group, and that easy collapsibility of small airways during expiration of tidal breath was not apparent in the CPFE OB+ group compared with the COPD group. Dynamic hyperinflation following metronome-paced incremental hyperventilation was significantly greater in the COPD group than in the CPFE OB− group, and also tended to be greater in the CPFE OB+ group than in the CPFE OB− group.ConclusionThe mechanisms underlying impairment of physiological function may differ among CPFE OB+ patients, CPFE OB− patients, and COPD patients. CPFE is a heterogeneous disease, and may have distinct phenotypes physiologically and radiologically.

Is the Metronome-Paced Tachypnea Test (MPT) Ready for Clinical Use? Accuracy of the MPT in a Prospective and Clinical Study

“…Therefore, in a group, the mean DH measured with MPT and CPET is interchangeable. Together with the studies of Lahaije et al [8] and Calligaro et al [3], it can be concluded that studies investigating the effect of therapy on DH [2, 3], the coherence of DH with other parameters [15], or the development of DH over time in a group with COPD patients [1, 7] can be simplified by measuring with MPT instead of using the more labor-intensive CPET. On an individual level, MPT should be used cautiously to determine, if a subject is a (non-) hyperinflator.…”

The Preoperative Composite Physiologic Index May Predict Mortality in Lung Cancer Patients with Combined Pulmonary Fibrosis and Emphysema

“…Emphysema and pulmonary fibrosis were evaluated using chest HRCT as previously described [3,21,22]. Briefly, emphysema was scored visually in the bilateral upper, middle, and lower lung fields according to the methods of Goddard et al [23].…”

“…The severity of emphysema was graded in accordance with the sum of the scores of the 6 dimensions, as follows: grade 0, total score = 0; grade 1, total score = 1-6; grade 2, total score = 7-12; grade 3, total score = 13-18; and grade 4, total score = 19-24 [24,25]. The detection of significant pulmonary fibrosis on HRCT, defined as the presence of honeycombing, reticular opacity, ground-glass opacity, consolidation, traction bronchiectasis, peribronchovascular interstitial thickening, and architectural distortion, was performed visually as previously described [1,3,21,22]. The extent of pulmonary fibrosis was scored visually to grade the severity as previously described [26].…”

Physiology of the lung in idiopathic pulmonary fibrosis

“…Some, but not all, patients with CPFE present with airway obstruction and hyperinflation [104]. Impulse oscillometry showed that the expiratory increase in the reactance of the respiratory system at low frequency (5 Hz), which indicates expiratory collapse of the distal airways, was much lower in CPFE than in COPD [104], consistent with the lack of dynamic hyperinflation in CPFE [104]. It is not known whether lung compliance is affected in CPFE to the same extent as in IPF without emphysema.…”