Impulse oscillometry: reference values in children 100 to 150 cm in height and 3 to 10 years of age

Area of Science:

• Pediatric Pulmonology
• Respiratory Physiology
• Biomedical Engineering

Background:

• Assessing pediatric respiratory function is crucial for diagnosing and managing lung diseases.
• The forced oscillation (Rfo) technique offers a non-invasive method for evaluating lung mechanics.
• Establishing normative reference equations is essential for interpreting Rfo measurements in children.

Purpose of the Study:

• To generate reference equations for respiratory function in North American children using the Rfo technique.
• To determine how oscillatory resistance, reactance, and resonant frequency (Fres) change with age, height, and weight.
• To assess the applicability of the Rfo technique in young children.

Main Methods:

• A prospective cross-sectional study involving 222 healthy children aged 3-10 years in Montreal, Canada.
• Measurements of resistance and reactance were taken at multiple frequencies (5-35 Hz) using an impulse oscillometer.
• Regression analysis was employed to develop predictive equations based on age, height, and body weight, stratified by gender.

Main Results:

• Standing height was identified as the sole significant predictor for all measured respiratory variables (resistance, reactance, Fres).
• Minimal variability was observed in repeated measurements within subjects, indicating high reliability.
• Coherence values were generally high (>0.9), though lower at 5 Hz and in younger children.

Conclusions:

• Respiratory resistance and Fres decrease with increasing height and age, while reactance increases.
• The Rfo technique demonstrated good acceptance among preschool-aged children, suggesting its utility in this population.
• These reference equations provide a valuable tool for assessing respiratory function in children.