Valores de referência brasileiros para a técnica de oscilações forçadas

• Autor(a) principal: Ribeiro, Fernando Carlos Vetromille
• Data de Publicação: 2015
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UERJ
• Texto Completo: http://www.bdtd.uerj.br/handle/1/8773
• topic: Forced oscillation technique; Reference values; Respiratory mechanics; Técnica de oscilações forçadas; Valores de referência; Mecânica respiratória; Valores de referência (Medicina); Mecânica respiratória; Testes de função respiratória Pulmões; Pulmões; CNPQ::CIENCIAS DA SAUDE::MEDICINA::CLINICA MEDICA::PNEUMOLOGIA

The forced oscillation technique (FOT) was first described by DuBois et al., in 1956, but was only recognized in medical practice in the 90s of the last century. However, so far, it is not completely standardized. This technique provides additional information about the ventilatory mechanics, being complementary to the other pulmonary function tests. Results are obtained requiring minimal cooperation through spontaneous breathing lasting from a few minutes. The survey provides respiratory impedance parameters for analysis of lung function, contributing data that facilitate the realization of respiratory function tests under conditions where traditional tests are not feasible. Most models to build equations of reference values for pulmonary function tests presupposes cross-sectional studies in individuals free of respiratory symptoms of any disease and nonsmokers. Strict methodological criteria require values obtained by trained operators using appropriate techniques and equipment in accordance with international standards. Furthermore, individuals studied to establish normal values should have similar characteristics to those of the reference population where equations are employed. There are already international benchmarks on grounds of sex, age and anthropometric characteristics, proposed in several international studies. In Brazil, there are no studies to define reference values for FOT. The main objective of this study was to establish reference values for FOT, using as dependent variables, among the various parameters of respiratory impedance, resistance at the intercept (R0), resistance at 6 Hz (R6), the mean reactance between 4 and 32 Hz (Xm) and dynamic compliance of the respiratory system (Cdyn). They evaluated 288 healthy subjects without respiratory symptoms and nonsmokers who came as volunteers to Biomedical Instrumentation Laboratory in State University of the Rio de Janeiro (UERJ). All subjects also underwent spirometry in order to avoid respiratory or allergic diseases. There was a statistically significant difference from all respiratory impedance parameters analyzed between men and women. Thus, different equations were derived for both genders. A multiple linear regression model using the independent variables age, height and weight was developed. The height showed the best correlation with all parameters being stronger for resistance. Age did not show significant result for the strength parameters in both genders, and only showed influence to Xm in women. The models were best fitted equations for R0 in logarithmic values and R6 in men and exponential equations for Cdyn values in men and women. Predicted values for FOT were obtained on a sample of the population and were expressed in equation form.