Medicina Pulmonar e Respiratória

Relationship between Lung Functions and Extend of Emphysema in Patients with Chronic Obstructive Pulmonary Disease

Abstract

Muzaffer Sariaydin, Nejat Altintas and Ozgur ince

Background: To investigate whether the extent of emphysema, visually confirmed by high resolution computed tomography (HRCT) in patients with COPD were associated with different indices of lung functions.

Methods: Eighty-two patients with COPD underwent HRCT scanning; visual assessment of HRCT scan was used in the calculation of extent of emphysematous

Destruction: The patients were clinically stable at the time of the evaluation. All subjects were smokers or past smokers who had smoked>10 pack-years.

Results: The mean visual emphysema score in all patients was 2.21 ± 1.11. While the mean emphysema score in patients with COPD GOLD (Global Initiative for Chronic Obstructive Lung Disease) stage 3 was 2.88 ± 1.03, it was 1.54 ± 1.16 in COPD GOLD stage 2 (p<0.001). There was a significant correlation between the emphysema score and the numbers of pack/years smoked (R=0.58, p<0.001). The visual emphysema score was inversely correlated with the FEV1(r =-0.56, p<0.0001), FVC (r=-0.38, p=0.001), FEV1/FVC (r=-0.43, p<0.001), PEF(r=-0.44, p<0,001) and with the Carbon monoxide diffusing capacity divided by the alveolar volume (DLCO/VA) (r=-0.50, p<0.001). In our study population, patients had a limited expression of the disease as represented by low scores in Saint George Respiratory Questionnaire (SGRQ), and there was no correlation between emphysema score and SGRQ.

Conclusions: HRCT visual scores correlated with functional indices of airflow obstruction and impaired lung diffusing capacity in patients with stable COPD of varying severity, the presence of pulmonary emphysemais best represented by the FEV1 and DLCO/VA.