Related Experiment Videos
Bronchodilator response in 3-6.5 years old healthy and stable asthmatic children
J Hellinckx1, K De Boeck, J Bande-Knops
1Dept of Pediatrics, University Hospital Gasthuisberg, Leuven, Belgium.
Insights
This study found no significant difference in bronchodilator response using impulse oscillation system measurements between healthy and asthmatic preschool children. A 40% change in respiratory system resistance at 5 Hz is proposed as a positive response cutoff.
Area of Science:
- Pediatric Pulmonology
- Respiratory Physiology
Background:
- Limited data exist on bronchodilator response in preschool children.
- Assessing lung function and asthma in young children presents unique challenges.
Purpose of the Study:
- To investigate baseline lung function and bronchodilator response in healthy and asthmatic children under 7 years old.
- To evaluate the utility of impulse oscillation system (IOS) in this age group.
Main Methods:
- 281 preschool children (2.7-6.6 years) underwent IOS measurements of respiratory system resistance (Rrs) and reactance (Xrs) at multiple frequencies.
- Measurements were taken pre- and post-inhalation of 200 mcg salbutamol.
- 34 children were diagnosed with asthma based on a validated questionnaire.
Main Results:
- No significant differences were observed in baseline IOS parameters or post-bronchodilator changes between healthy and asthmatic children.
- Significant scatter was noted in the measurements.
- A 40% decrease in Rrs at 5 Hz was identified as a potential cutoff for a positive bronchodilator response.
Conclusions:
- Impulse oscillation system measurements did not differentiate between healthy and asthmatic preschool children in this cohort.
- Further research is needed to establish robust diagnostic criteria for pediatric asthma using IOS.
- A 40% reduction in Rrs at 5 Hz may serve as a threshold for bronchodilator responsiveness in young children.
Abstract:
Few data are available on the bronchodilator response in preschool children. This study was set up to study baseline lung function and bronchodilator responses in healthy and asthmatic children younger than 7 yrs old. In 281 preschool children attending kindergarten (age range 2.7-6.6 yrs old) respiratory system resistance (Rrs) and reactance (Xrs) by impulse oscillation system at 5, 10, 15, 20, 25 and 35 Hz as well as resonance frequency (f0) were measured before and 20 min after 200 microg inhaled salbutamol by a metered-dose inhaler connected to a spacer device. Thirty-four of them were diagnosed as asthmatics based on a validated standardized questionnaire. The mean Rrs (+/-SD) at 5 Hz (Rrs,5) was 1.03 (+/-0.24) kPa x L(-1) x s for healthy children and 1.09 (+/-0.26) kPa x L(-1) x s for stable asthmatics. The mean change in Rrs,5 after salbutamol was -0.13 (+/-0.20) kPa x L(-1) x s for the healthy children and -0.09 (+/-0.25) kPa x L(-1) x s for the asthmatic group. The scatter for the measurements was striking. Neither baseline values of impulse oscillation nor its changes after bronchodilator administration was significantly different between healthy and stable asthmatic children. A change in respiratory system resistance at 5 Hz of 40% is to be considered the cut-off for a " positive" bronchodilator response.