Identification of new spirometric indices predicting severe COPD

Abstract

Introduction: Grading the severity of COPD is based traditionally on the forced expiratory volume in the first second FEV1 (%).

Objectives: To identify new spirometric indices in addition to FEV1 (%) predicting severe COPD.

Methods: This was a retrospective study conducted at the functional exploration department of Sfax Tunisia including patients with COPD. COPD was defined as a FEV1s/Forced vital capacity (FVC) ratio < 70% after a BD. The severity of COPD was assessed basing on the FEV1 (%) post (BD). Thus, COPD is severe if FEV1 (%) post (BD)<50 %. The forced expiratory time (FET), the forced vital capacity (FVC), the forced expiratory volume FEV 3 were recorded. Analyses were performed using the SPSS 20 software. A p < 0.05 was significant.

Results: One hundred and forty-five patients were included. The mean age (years) was respectively 65.43 ± 9,7. The COPD was severe in 44.1 % (G1). Compared to non-severe COPD (G2), the G1 had significantly lower FEV 3(l), lower FVC (l) /FET and lower FVC (%) /FET before and after BD. The mean of FVC(l)/FET before BD in G1 and G2 were respectively 0.30 ± 0,12 and 0.43 ± 0,15. In addition, there was a strong significant correlation between these ratios and the FEV 1 (%) (r > 0.6, p<0.05).

Conclusion: The FVC /FET ratios seem to be useful to predict severe COPD