Peak Expiratory Flow Rate: A Useful Tool for Early Detection of Airway Obstruction in School Children

Peak expiratory flow rate (PEFR) is an effort-dependent parameter, emerging from the large airways within about 100-120 msec of the start of forced expiration. It measures the degree of obstruction in the airways. A child from an asthmatic family, having significantly low PEFR values than its height and age matched peers, can be considered under impending asthma category.

The present study was proposed to detect early stages of airway obstruction in school going children.

Observational study conceived in the department of Physiology, AIIMS, Jodhpur, Rajasthan.

Hundred students of age group 7-15 years participated in the study. A family history for presence/absence of asthmatic symptoms was taken from all subjects. After anthropometric examination, PEFR values were recorded in standing position, using the Mini Wright Peak Flow meter after demonstrating them the right procedure. Three measurements were taken and the highest reading was recorded.

Fisher’s exact test was done to calculate the two tailed ‘P’ value, Odd’s ratio and relative risk.

Thirty-one Percent children with family history of airway obstruction showed PEFR values below 80% of the predicted value, while 5.74% who were not having any family history of asthma, also showed values below 80% of the predicted value. With Fisher’s exact test, the two tailed ‘P’ value was 0.0155 (significant).

The results of this study support the vital role of PEFR related to changes in airflow, which eventually can result in early identification of children with airway obstruction.