Impulse oscillometry: pulmonary function assessment in preschool children

ABSTRACT

Objectives

In contrast to spirometry, which requires active participation of the individual and is challenging for the preschool age group, the impulse oscillometry system comprises a test that minimizes the degree of coordination required. The study aimed to compare the results of Impulse Oscillometry System (IOS) in children with and without respiratory symptoms.

Methods

A cross-sectional study was conducted in children aged between 3 and 6 years. A short version of the ATS-DLD-78-C questionnaire validated for Brazilian children was applied to identify two groups: children with and without respiratory symptoms. The IOS analysis was carried out measuring the following parameters in triplicate: resistance at 5 Hz (R5Hz) and 20 Hz (R20Hz), respiratory reactance at 5 Hz (X5Hz), and R5-R20Hz before and after bronchodilator application.

Results

A total of 76 preschoolers were selected, 55 (72.4%) of whom had respiratory complaints. The coefficient of variability of R5Hz was ≤17% in 70/76 (92.1%) of the children. Resistances at R5Hz and R5-R20Hz in the children with respiratory complaints reached values higher than those of children without symptoms before bronchodilation.

Conclusions

The results obtained for resistance using IOS in children with respiratory symptoms were higher in the pre-bronchodilator examination for R5Hz and R5-R20Hz compared to those of children without respiratory symptoms.

Expert opinion

Prospective investigations suggest that irreversible changes in lung function begin in infancy, before reaching school age. Pulmonary function follow-up in children with recurrent wheezing or asthma is important for confirmation of diagnosis and evaluation of the disease severity. The Impulse Oscillometry System (IOS) can be useful in assessing children’s pulmonary function since it requires minimal patient cooperation and can be successfully applied to preschool children being an alternative to individuals who have difficulty performing spirometry.

KEYWORDS:

• Pulmonary function test
• oscillometry
• child
• preschool
• airway resistance
• bronchodilators

Article highlights

• In contrast to spirometry, which requires active participation of the individual and is challenging for the preschool age group, the impulse oscillometry system comprises a test that minimizes the degree of coordination required.

• In preschoolers, pulmonary evaluation is rarely performed in clinical practice, although existing techniques have been improved, enabling the routine study of pulmonary function in these children.

• Children with respiratory symptoms show resistance values at 5 Hz, in the R5-R20 difference and 5 Hz elastance higher than children without respiratory symptoms.

• Bronchodilator response was higher in children with respiratory symptoms.

• Pulmonary function assessments are essential for diagnosis and monitoring of pulmonary diseases in preschool children.

• IOS is a tool that can help assess pulmonary function in preschool children.

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This paper was not funded.