Promoting the inclusion of vital-capacity data in the bronchodilator response

Abstract

Helmi Ben Saad Laboratory of Physiology, Faculty of Medicine of Sousse, University of Sousse, TunisiaI read with interest the manuscript of Torén et al1 asking for a change in the interpreting way of the reversibility test. The authors have opted for a difference between the predicted normal values after and before bronchodilation (ABD, BBD, respectively).1 They have included three spirometric data (forced expiratory volume in the first second [FEV1], forced vital capacity [FVC] and slow vital capacity [SVC]), and they have proposed three thresholds to be significant at 9, 4 and 6%, respectively, for FEV1, FVC and SVC. Such papers are encouraged since vital-capacity (FVC and SVC) data are still “neglected” by the Global Obstructive Lung Disease (GOLD).2 Moreover, in the GOLD 2017 Report, it was clearly stated that “assessing the degree of reversibility of airflow limitation does not aid the diagnosis of COPD, differentiate COPD from asthma, or predict the long-term response to treatment.”Author replyKjell TorénSection of Occupational and Environmental Medicine, University of Gothenburg, Gothenburg, SwedenWe appreciate the comments by Dr Ben Saad and take the opportunity to add a few remarks: 1) The difference between the values after bronchodilatation (% predicted normal) minus the value before bronchodilatation (% predicted normal) is rather insensitive to the particular reference equation applied to calculate the predicted normal. 2) The final conclusion by Dr Ben Saad that forced vital capacity and slow vital capacity should be included when assessing the effect of bronchodilatation is quite in line with our opinion.View original paper by Torén et al

Keywords

• FVC
• SVC
• Reversibility test
• chronic obstructive pulmonary disease