Novo parâmentro para equações de referência de VEF1 e CVF em crianças e adolescentes: a circunferência do braço como variável independente

• Ano de defesa: 2013
• Autor(a) principal: Sarah Costa Drumond
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; UFMG
• Palavras-chave em Português: Equações de referência; Função pulmonar; Criança e adolescente; Estado nutricional; Volume expiratório forçado; Espirometria; Medidas de volume pulmonar; Valores de referência; Pulmão; Circunferência braquial; Criança; Adolescente; Pediatria
• Link de acesso: http://hdl.handle.net/1843/BUBD-9E3FC2

Spirometry is a test that evaluates lung function by measuring the volume of air inspired or expired in function of time. This examination is important in diagnosing and monitoring respiratory diseases. The pulmonary function tests are often interpreted based on the comparison of measured values with reference values derived from healthy individuals with no chest deformities. Most reference equations for spirometry uses the age and height as independent variables. Other uses weight. However, due to the impossibility of measuring the weight and height in certain groups of patients such as those with certain neuromuscular diseases, the analysis of lung function becomes impaired. Faced with the need to create equations which fitted the lung function of children and adolescents with these limitations, considering a sample of 243 children and adolescents were estimated and validated predictive equations for forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) FVC maneuvers using age and arm circumference as independent variables. This measure reflects the nutritional status and is an alternative recommended by the World Health Organization (WHO) for patients whose medical conditions do not allow to obtain the height and arm span. Statistical analysis was based initially on measures of central tendency and variability of all the variables observed. To evaluate the association between performance spirometric and anthropometric measurements, we used the coefficient of linear correlation and paired samples Student t test to allow comparison between the values predicted by the equations of reference and measured with use the spirometer. The development of predictive equations for FVC and FEV1 was based on the setting of linear regression models, methodology also used to validate these equations. In all statistical tests, was considered a 5% level of significance. Comparison of FEV1 and FVC, calculated by the equations proposed in this study, with the values predicted by HSU et al. and Polgar and Promadhat showed significant differences for children and adolescents, demonstrating that these equations are shown limited use when applied to the sample used in this study. The FVC predicted by Mallozi and the equation proposed in this study did not differ from measured values in children. In relation to FEV1, only the proposed equation showed this positive outcome. This study contributed to the construction of an equation that uses an alternative arm circumference and age as independent variables and validated it, allowing thereby the safe interpretation of spirometric assessment in patients in situations where it is not possible to evaluate the weight, height and armspan.