[Evaluation of systematic pulmonary function testing for asthma in children aged three to five years].

UNLABELLED: Pulmonary function testing is not usually done in the preschool child, despite the recent data showing early deterioration in airway function in asthma.

METHODS: We evaluated feasibility and clinical interest of flow-volume loop by forced expiratory maneuver and measure of airway resistance by interrupter technique (interrupter resistance), before and after inhalation of salbutamol, in 75 children aged three to five years seen in the ambulatory setting for asthma.

RESULTS: Feasibility rate (92%) and reproducibility rate (91%) of those techniques were good, so that 84% of the cases could be exploited (63 children of 75). We found few significant associations between clinical parameters and flow-volume loop. We found a significant association between elevated interrupter resistance at basis and night-symptoms (P = 0.03), between diminished interrupter resistance after salbutamol and exercise-symptoms (P = 0.03), symptoms in the ambulatory setting (P = 0.02) and absence of inhaled corticosteroid treatment (P = 0.046). Pulmonary function testing resulted in treatment modification in 14% of cases.

CONCLUSION: Our study shows that flow-volume loop and measure of airway resistance by interrupter technique can be done with a good reproducibility in the preschool child. Interrupter resistance appears to be better correlated than flow-volume loop with usually evaluated clinical parameters.