Respiratory impedance and bronchodilator response in healthy Italian preschool children

Area of Science:

• Pediatric Pulmonology
• Respiratory Physiology
• Biomedical Engineering

Background:

• Assessing lung function in preschool children is challenging.
• Normal reference values for respiratory resistance (R(rs)) and reactance (X(rs)) are crucial for diagnosing respiratory conditions.
• The forced oscillation technique (FOT) offers a non-invasive method for measuring these parameters.

Purpose of the Study:

• To establish normal reference equations for R(rs) and X(rs) in healthy Italian preschool children.
• To define normal bronchodilator response (BDR) in this population using FOT.
• To provide clinically applicable cut-off values for identifying significant BDR.

Main Methods:

• Respiratory resistance and reactance were measured in 163 healthy Italian preschool children using a commercial forced oscillation device.
• Regression analysis was used to develop reference equations considering height, weight, age, and gender.
• Bronchodilator response was assessed after salbutamol administration, with changes calculated as absolute values, percent change, and Z-score changes.

Main Results:

• Reference equations for R(rs) and X(rs) were successfully established and found to be primarily related to height.
• The coefficient of repeatability for R(rs) at 8 Hz was 1.53 hPa s L(-1) and for X(rs) at 8 Hz was 0.91 hPa s L(-1).
• Recommended Z-score cut-off values for a positive BDR were -1.88 for R(rs8) and 2.48 for X(rs8).

Conclusions:

• Reference equations for R(rs) and X(rs) were successfully established for healthy Italian preschool children using FOT.
• The study provides recommended Z-score cut-off values for a positive bronchodilator response in this population.
• These findings facilitate the objective assessment of airway obstruction and response to bronchodilators in young children.