Background: Asthma is the most common chronic disease of childhood and the leading cause of morbidity from chronic illness. The challenge was the difficulty to make diagnosis of asthma in children 5 years and younger.
Objective: To evaluate the results of pulmonary function data by impulse oscillometry in young children with recurrent wheeze, its value to diagnose asthma, and to compare IOS data with result of asthma predictive index in young children.
Methods: A case control study was conducted on 60 children enrolled from the pediatric pulmonology and allergy outpatient clinic of Al-Hussein university hospital. Forty patients (group-1), were subdivided into group A: wheezy with positive Asthma predictive index and group B: wheezy with negative API, and 20 children ( group-2): The patients were presented with recurrent attacks of wheeze suggestive clinically to be asthmatic (GINA,2018). All children were subjected to full history, physical examination, and pulmonary function by Impulse oscillometry (IOS). Absolute eosinophilic count (AEC) for patient group.
Results: This study revealed that the IOS parameters were significantly higher in patients compared to controls including pulmonary resistance (R5); respiratory reactance (X5); small airway resistance (R5-R20); Frequency (Fres) and reactance area (Ax). In patients there were a significant higher values pre than post bronchodilator as regard R5, R5-R20, Fres. and Ax. Also X5 parameter showed a significant change, being more negative pre- than post-bronchodilator, There were significant high values of IOS parameters in patients with positive API compared to those with negative API. There was positive correlation between AEC and IOS parameters post-bronchodilator. Also there was a significant association between asthma control score and asthma control using the reactance area (Ax) < 7 kPa/L.
Conclusion: Our study concluded that: IOS is helpful for diagnosis of asthma in children 5 years and younger, as it is sensitive and specific in identifying children with reversible obstruction. There was positive correlation with IOS parameter and AEC. This study showed usefulness of IOS and API to categorize the severity of the disease, and determination of asthma control using the reactance area (Ax) < 7 kPa/L. that reflects the degree of peripheral small airway obstruction.