Summary: The interrupter technique for measuring airway resistance is a noninvasive method reported to require minimal subject cooperation. Therefore it has a good potential for use in young children who are not able to cooperate with conventional lung function tests. The interrupter method is based on transient interruption of airflow at the mouth for a brief period during which alveolar pressure equilibrates with mouth pressure.
In order to investigate the compliance rate with the interrupter technique in preschool children and to look for associated baseline measures of RINT we performed a study in 214 children of ages from 3 months to 5 years.
There was a significant inverse correlation between baserint and age (r = -0.672, p<0.001), and standing height (r = -0.692, p<0.001) in children with recurrent wheezing. However, this was not seen in healthy children.
We concluded that the portable interrupter device is very useful in preschool children. The measurements showed that the age and standing height are inversely proportional to the baseline RINT values measured. We reported that these differences would be more apparent in children with a history of recurrent wheezing.

Key Words: Airway resistance - Children - Lung function - Preschool