[Comparative study of plethysmography and spirometry in asthmatic children].

The aim of the study was to evaluate the results of plethysmography in comparison to spirometry. A retrospective study of pulmonary function tests was performed in 50 asthmatic children, 6 to 15 years old, free of acute symptoms. Mild airway obstruction was found in 8 spirometries, while the other 42 were found within normal limits. In the plethysmography, obstruction was found in 27 cases, 23 without abnormalities in resistance or specific conductance. Eleven cases suggested pulmonary air trapping and/or hyperinflation. Airway obstruction was evident in 54% of plethysmographies. The difference between both studies was significant, also as well as the airway obstruction and intensity of the clinical disease. We therefore conclude that the plethysmography shows more alteration in their parameters than spirometry for the detection or suggestion of airway obstruction in asthmatic children during asymptomatic periods.