Peak expiratory flow (PEF) in monitoring children with asthma

Abstract

The primary aim of this study was to investigate if there is relationship between asthma symptoms and diurnal variability in peak expiratory flow (PEF) before starting maintenance treatment with inhaled corticosteroids. The secondary aim was to evaluate the effect of one year treatment on morning peak expiratory flow and its daily variability. Forty asthmatic children, 26 boys and 14 girls, aged 6.7-17.3 years (mean age 10.3 years ) were followed two weeks before and one year after starting maintenance treatment with inhaled corticosteroids. Fourteen days before starting therapy mean asthma symptom score correlated well with mean daily PEF variability (r=0.92, p<0.001) and was inversely related to mean morning PEF (r=-0.87, p<0.001). During one year of treatment the mean morning PEF significantly increased (p<0.001) and PEF variability significantly decreased (p<0.001). At the same time there was a statistically significant negative correlation between morning PEF and its variability (r=-0.9, p<0.0001). Peak expiratory flow monitoring was introduced many years ago but it is still not widely used. Therefore, we wanted to stress the importance of PEF monitoring, especially its daily variability in asthmatic children, since it is an objective tool for assessing variable obstruction, diagnosing asthma and monitoring response to treatment.