291 RESPIRATORY MECHANICHS IN INFANTS WITH ACUTE BRONCHIOLITIS

Abstract

Objective: to determine alterations in pulmonary function tests in infants in acute phase of bronchiolitis. Subjects and methods: Partial forced expiratory flow-volume curves obtained by an inflatable jacket and end-inspiratory single occlusion test were used to determine maximal flow at Functional Residual Capacity (VmaxFRC) and total respiratory system compliance and resistance (Crs, Rrs) in 54 previously healthy infants in acute phase of bronchiolitis and in 44 healthy control infants aged 1-12 months. PEDS and PUFF systems (Medical Associates, Hatfield, Pa, USA) were used for these measurements. Results: see table. Table: age (yr); Length (cm); VmaxFRC (mL/s). (mL/cmH2O). Rrs (cmH2O/Ls). % Predicted by Tepper et al. Am Rev Respir Dis 1986;134:513-9. Mean (standard deviation). Comparision by t test for independent samples. NS: no significative. Conclusion: Important decrease in VmaxRFC and compliance with no significant increase in resistance characterizes acute phase of bronchiolitis.