ABS47: Flow and volume responses after bronchodilation in mild to severe COPD

To investigate the relationship between the severity of COPD and responses in terms of changes in exhaled flow and volume during routine bronchodilator reversibility testing. Study We used data from the “Stichting Huisartsen Laboratorium” (SHL) Breda, a regional diagnostic centre that provides a range of diagnostic and health care services for GPs in the South-Western part of the Netherlands. Patients aged =40 years diagnosed as COPD by a respiratory consultant of the SHL were categorized according to disease severity using GOLD criteria. Spirometric tests were performed by trained lung function technicians using SpiroPerfect® PC based spirometers. Cross-sectional univariate analysis of the association between the GOLD stages and the forced expiratory volume in 1 sec (FEV1) and vital capacity (VC) response after bronchodilator testing. 887 patients (63.5% males) with a diagnosis of COPD were analysed, 227 GOLD I, 547 GOLD II, 113 GOLD III/IV. Mean age was higher for each successive GOLD-stage (62.0; 63.5 resp. 65.6 years, p < 0.05). Mean FEV1 % predicted was 68.8 (SD 16.2). FEV1 response decreased with increasing GOLD stage (p = 0.015): GOLD I 0.193 litres (SD 0.199), GOLD II 0.187 (SD 0.173), GOLD III/IV 0.140 (SD 0.168). In contrast, VC responses increased as the disease was more severe (p = 0.010): GOLD I 0.149 (SD 0.199), GOLD II 0.199 (SD 0.266), GOLD III/IV 0.232 (SD 0.343) litres. Response on bronchodilator in terms of flow (FEV1) decreased as GOLD stage was more severe, whereas the volume (VC) response increased along with the severity of COPD. Conflict of interest and funding None. Funding: Boehringer Ingelheim.