Spirometric values in healthy preschool children

Introduction. Spirometry is the most commonly used test to evaluate lung function. Foreign reference standards are currently available for preschool children. Objectives: 1. To measure spirometric variables in healthy Chilean preschool children, 2. To compare these results with predictive ones according to GLI (Global Lung Initiative), Eigen (USA) and Franca (Brazil), and 3. If there is a significant difference with these, to develop reference equations. Subjects and Method: Questionnaires were distributed to parents in several schools and kindergartens in Santiago. Children with a history of prematurity, asthmatic symptoms, chronic lung disease (including asthma), and chronic non-respiratory disease were excluded. Spirometry was performed according to ATS/ERS 2007 guidelines, with MedGraphics equipment, USA. Family and environmental background, weight and height were recorded, as well as values obtained in forced vital capacity (FVC), forced expiratory volume in 0.5, 0.75 and 1 second (FEV0.5, FEV0.75, and FEV1, respectively). Results: 276 spirometries were performed, 202 met acceptability criteria, 112 girls, average age 5.01 +/- 0.57 years, height 108.7 +/- 5.6 cm. When comparing by gender, there was only a significant difference in FVC, which was higher in boys. The average values obtained in the total group were: FVC 1.22 +/- 0.22 liters, FEV1 1.16 +/- 0.18 liters, FEV0.75 1.07 +/- 0.17 liters. These parameters were higher in percentage than the predictive ones according to GLI, Eigen, and Franca, except FVC with Eigen, therefore, predictive equations were developed. Conclusions: Spirometric values of preschoolers living in Santiago were higher than foreign reference values. We proposed these reference standards to be used in our country.