106 Spirometric Pulmonary Function in 3- to 5-Year-Old Children

Forced expiratory maneuvers are routinely used in asthmatic children 6 years of age and older for the diagnosis and follow-up of respiratory disease.

To establish normative data for forced spirometry in healthy 3 to 5 years old children in our population.

Caucasian children aged between 3 and 5 years without acute or chronic respiratory disease were tested in 11 different daycare centers representative of the population of our region. Measurements were obtained by two respiratory therapists with pediatric experience in May and June. Each child had a maximum of 15 minutes to achieve 3 technically acceptable and reproducible efforts. Validity of the curves was determined by two pediatric respirologists and one respiratory therapist. Usual parameters, including FEV₁, FVC and PEF, were measured and analyzed in relation to sex, age, height and weight. In addition, due to the relative frequency of expiratory maneuvers lasting one second or less, the same analysis was performed for FEV_0.5 and FEV_0.75 (i.e., forced expiratory volume at 0.5 and 0.75 seconds respectively).

One hundred forty four children were tested, including 75 girls (52%) and 69 boys (48%). Twenty-three were 3 years old, 56 were 4 years old and 64 were 5 years old. In all, 127 (88%) children were able to perform at least two valid expiratory maneuvers, including 83% of the children at 3 years, 86% at 4 years and 94% at 5 years (not significantly different). Analysis using a linear regression model showed that height was the most satisfactory predictor of FEV₁ (FEV₁=–0.978+0.02×height, r=0.67), FEV_0.75 (FEV_0.75=–0.822+0.017×height, r=0.63) and FEV_0.5 (FEV_0.5=–0.568+0.014×height, r = 0.56). Similar results were obtained for the other parameters measured. Reproducibility of FEV₁ was very high, with the difference being less than 10% in all children and less than 5% in 85% of the children.

Most healthy 3 to 5 years old children in our population can perform valid forced expiratory maneuvers. Consistent with other studies, we found that height is the most important single predictor of FEV₁. This is the first study to establish normal values for FEV_0.5 and FEV_0.75. Further studies are in progress to validate the hypothesis that forced spirometry can be used to detect and follow respiratory diseases in the same age group.