Critérios de reprodutibilidade e pressões respiratórias máximas: comparação entre as recomendações nacional e internacional

Abstract

The assessment of maximal respiratory pressures (MRP) is the most widely non-invasive method used in the clinical practice to evaluate the respiratory muscle strength. It consists in the measurement of inspiratory (MIP) and expiratory (MEP) maximum pressures, performed against an occluded airway. In order to ensure the selection of maximal efforts, some reproducibility criteria have been suggested. It can be highlighted the ones proposed by the American Thoracic Society (ATS) and European Respiratory Society (ERS), and by the Brazilian Thoracic Association (SBPT), both from 2002. However, there were found no studies in the literature that confronted these two reproducibility criteria. The objectives of the present study were to assess the number of maneuvers required to achieve maximum performance and to compare the pressure values selected from the use of the reproducibility criteria proposed by the ATS/ERS and by SBPT. Ninety-nine healthy subjects, with normal ventilatory function, from both sexes, were evaluated. They were selected from the internal and external community of the Federal University of Minas Gerais (UFMG). The volunteers underwent MRP assessments, respecting the recommendations proposed by the ATS/ERS and by the SBPT, registering the pressure values selected, and the number of measures needed to satisfy each reproducibility criterion. For statistical analysis, it was used the mean and the standard deviation for sample characterization, followed by paired Student's t test and Wilcoxon test, according to the normality of the data. The results showed that a greater number of maneuvers were required to achieve the reproducibility criterion proposed by SBPT, for both MIP and MEP measures. Also, the use of this criterion resulted in the selection of higher pressure values. It can be concluded that the use of the reproducibility criterion proposed by the SBPT resulted in the selection of pressure values closer to the individual’s maximal capacity.