Variability of peak flow in wheezy children

Area of Science:

• Pediatric Pulmonology
• Respiratory Physiology

Background:

• Asthma diagnosis in children relies on identifying variable airflow obstruction.
• Peak expiratory flow (PEF) variability is a key indicator of asthma severity and control.
• Previous studies on PEF variability primarily focused on adult asthmatic populations.

Purpose of the Study:

• To assess peak flow variability in a population sample of wheezy children.
• To compare PEF variability in children with previously reported data in adults.
• To evaluate the utility of peak flow diaries in demonstrating airflow obstruction in pediatric asthma.

Main Methods:

• A 12-day peak flow diary study was conducted in 63 wheezy children (aged 9-11 years).
• PEF recordings were taken three times daily: morning, after school, and bedtime.
• Cosinor analysis was used to determine daily rhythm and amplitude of PEF variability.

Main Results:

• 89% of children experienced symptoms during the study period.
• Mean daily PEF amplitude was 17% of the mean daily value (range 4-48%), with cosinor analysis showing 12% (range 1-53%).
• The lowest point of the daily rhythm occurred between midnight and 8 am in 65% of children, but was statistically significant in only 22%.

Conclusions:

• PEF variability in these wheezy children was lower than previously reported in adult asthmatics.
• A peak flow diary alone may have limited value in demonstrating the variable airflow obstruction characteristic of childhood asthma.
• Further research may be needed to establish optimal methods for assessing airflow obstruction in pediatric asthma.