[Assessment of reversibility in airway obstruction].

In the medical literature there have been described some methods to determine bronchodilator response. They are different because of the required percentage increase in FEV1 and /or FVC and the way of expressing results -as the percent of predicted or initial value. This study on 38 subjects evaluated that there is better bronchodilator responses when the results are presented as the percentage of the initial value compared with the predicted value. The intensity of improvement in FEV1 depends on the baseline airway obstruction. There are more meaningful responses in subjects with 'poor' initial value when using the criteria of change in FEV1 as a percentage of initial value. About 10% of positive responses are misunderstood as 'poor' when it was considered improvement only in FEV1 (they are positive with reference only to FVC).