Longitudinal evaluation of pulmonary function in preschool children with asthma using oscillometry

• DOI: 10.22533/at.ed.14423280310

• Palavras-chave: Sons respiratórios, asma, testes respiratórios, oscilometria

• Keywords: Respiratory sounds, asthma, respiratory tests, oscillometry.

• Abstract:

  Introduction: The Impulse Oscillometry System(IOS) is useful for evaluation of pulmonary function in children, since it does not require their active collaboration. Objective: to assess pulmonary function in preschool children diagnosed with asthma attending a specialized clinic and to re-evaluate them 12 months later. Method: The pulmonary function of children with asthma(aged 3 to 6 years) was evaluated using IOS at the admission of the study and after 12 months of follow-up. Total resistance at 5Hz(R5), central resistance at 20Hz(R20), the difference between these(R5-R20), reactance at 5Hz(X5) and the reactance area(AX) were measured before and after inhalation of bronchodilator. A reduction of 40%, 50% and 80% or greater for R5, X5 and AX respectively was deemed to constitute a positive response. Results: All the children(n=58) performed the pulmonary function evaluation correctly. There was no difference between R5 and X5(percentage of predicted) at the outset of the study and that registered at the end. In the first year, 24% and 36% of the children presented abnormal values of R5 and X5, respectively; and, in the second year, the figures were 29% and 53%. In six children R5 was increased on both visits and in 14 X5 was abnormal. Bronchodilator response was not frequent and changes were most observed in X5. Conclusion: Early abnormalities in pulmonary function can be observed in almost half preschoolers with asthma in spite of specialized care and treatment. This demonstrates the need for long-term specialized treatment, including monitoring of pulmonary function, and clinical follow-up in these patients.