EVALUAREA RĂSPUNSULUI BRONHODILATATOR UTILIZÂND TEHNICA.

Background: Respiratory function exploration is difficult in children, especially in younger ages, because of the lack of cooperation for forced expiratory manoeuvres. The interrupter technique is particularly attractive in a pediatric setting as it requires only passive cooperation from the child. Objectives: Assessing the sensitivity and specificity of this method for detecting bronchodilator responsiveness in asthmatic children. Methods: The study was conducted in children with asthma, able to perform forced expiratory maneuvers. Baseline and postbronchodilator volumes and flows by spirometry and airway resistance by the interrupter technique were measured. The measurements were made at baseline and after inhaled salbutamol 400 μg . Children were divided in 2 groups according to the presence (group 1) or absence (group 2) of significant bronchodilator reversibility based on the spirometry. The correlation between Rocc and volumes and flows was then calculated in the two groups. Results: Of the 54 children 10 cases showed significant bronchial reversibility in spirometry. Baseline Rocc, but not postbronchodilator Rocc, was significantly higher in group 1 vs. group 2 (0.89 ± 0.20 kPa/L/s vs. 0.63 ± 0.18 kPa/L/s, p < 0,0001; 0.66 ± 0.21 kPa/L/s vs. 0.55 ± 0.16 kPa/L/s, p = 0,067, respectively). Rocc's changes after bronchodilator (?Rocc, expressed as percentage of change from baseline value) in the 2 groups were -19.22 ± 23.53% in group 1, and -10.31 ± 18.87% in group 2 (p = 0.06). The optimal ?Rocc cutoff value given by receiver operating characteristic curves to discriminate between children with the presence or absence of significant reversibility in FEV1 yielded 50.0% sensitivity and 86.4% specificity (cutoff value -25%, area under the curve 0.692). Conclusion: Rocc measurements allow reliable evaluation of bronchodilator responsiveness in asthmatic children and could be used as an alternative method to the spirometry when it is not feasible. [ABSTRACT FROM AUTHOR]