Repeatability and bronchodilator reversibility of lung function in young children

Area of Science:

• Pediatric Pulmonology
• Respiratory Physiology

Background:

• Assessing lung function repeatability is vital for interpreting changes in children's respiratory health.
• Understanding variability helps differentiate disease progression, treatment effects, and normal fluctuations.

Purpose of the Study:

• To evaluate the short-term repeatability of multiple-breath washout indices and specific airway resistance in healthy children and those with stable wheeze.
• To determine the suitability of these lung function measures for assessing bronchodilator reversibility in pediatric populations.

Main Methods:

• Measurements included lung clearance index, conductive ventilation inhomogeneity (Scond), and specific airway resistance (sRaw).
• Tests were conducted at baseline and 20 minutes post-bronchodilator (salbutamol) in 28 healthy children and 62 wheezing children.
• Repeatability was assessed by comparing baseline variability and bronchodilator response.

Main Results:

• Baseline variability for multiple-breath washout indices and sRaw did not significantly differ between healthy children and wheezers.
• Significant bronchodilator reversibility was observed for Scond only in wheezers (16%) and for sRaw in both wheezers (37%) and healthy controls (20%).
• Some participants showed increased multiple-breath washout indices post-bronchodilator.

Conclusions:

• Lung clearance index and sRaw exhibit low baseline variability in both healthy and diseased subjects.
• Multiple-breath washout indices and sRaw are not ideal for assessing bronchodilator reversibility in young children with stable wheeze.
• These findings aid in interpreting therapeutic intervention effects on pediatric respiratory diseases.