Although respiratory diseases and other clinical conditions in the pediatric population are some of the main causes of morbidity and mortality in childhood,1,2 many of them have not often been evaluated by objective measures in clinical practice. There are several reasons for this in children, mainly the fact that many tests are not standardized.3 It is difficult for the subjects to understand and cooperate, there is low reproducibility, and also lack of information on certain methods among health care professionals, as part of the evaluation of many lung conditions and diseases.3