Spirometric and exhaled nitric oxide reference values in preschool children from the community of Navarra.

BACKGROUND AND OBJECTIVE: Preschool children can perform quality, reproducible spirometric maneuvers, provided appropriate equipment is used and specially trained nursing staff training are available. However, use of spirometry for the diagnosis and follow-up of preschool children with respiratory diseases remains limited in clinical practice, because consensus on test quality and acceptability criteria and reference data are lacking. We initiated the present study with the aim of developing reference equations, since tables of normal values for this age group are not available in our area. PATIENTS AND METHODS: The study population comprised healthy preschool children in our community. Normal values for exhaled nitric oxide in this age range were assessed. Regression equations were constructed using univariate and multivariate models. RESULTS: A total of 114 healthy preschool children aged 3 to 6 years were enrolled. According to the criteria of the American Thoracic Society/European Respiratory Society, 60 children were able to perform acceptable and reproducible spirometric maneuvers. The best correlations were observed for the untransformed linear regression model that included height. The correlation coefficients for forced vital capacity (FVC), forced expiratory volume in the first second (FEV1), and FEV0.5 were 0.89, 0.88, and 0.86, respectively. The regression equations for the calculation of reference values were as follows: FVC = -2.6 + 0.036 x height, cm FEV1 = -2.04 + 0.029 x height, cm FEV0.5 = -1.53 + 0.022 x height, cm. We obtained fraction of inhaled nitric oxygen (FeNO) values for 56 children. The mean (SD) value was 11 (4.9) ppb. CONCLUSIONS: Most preschool children in our area were able to perform quality spirometry maneuvers. We obtained regression equations that allowed us to calculate the reference ranges in our population and the distribution of normal FeNO values.

[Spirometry quality in preschool children]. / Calidad de la espirometría en preescolares.

BACKGROUND: Carrying out quality spirometric maneuvers in preschool children in both the diagnosis and follow-up of respiratory diseases continues to be very scarce. This is due to several reasons, including a lack of consensus on quality criteria and the acceptability of the test. The purpose of this study is therefore to obtain reference norms from a population of healthy preschool children from the Autonomous Community of Navarre (Spain). METHOD: A total of 114 healthy preschool children aged between 3 and 7 years of age, without prior experience in carrying out lung function tests, were included. RESULTS: A total of 76 were able to realize at least two acceptable spirometric maneuvers, and 60 of them maneuvers that were acceptable and reproducible, according to ATS/ERS criteria. This represents a global success percentage of 59%. The most common failing was premature and brusque termination of the spirometric maneuver, followed by an inadequate peak in breathing. CONCLUSIONS: Over half of the preschool children were able to realize quality spirometric maneuvers. Our data make it possible to recommend the proposed quality criteria as being suitable for routine use, and to encourage the use of spirometry in regular clinical practice within the setting of specialized care.