[The evaluation of lung function by using forced oscillation technique for children with asthma].

BACKGROUND

Lung function measurements are useful objective indices to monitor asthma control in children. Recently, a new forced oscillation technique machine called MostGraph (Chest Co. Ltd., Tokyo, Japan) has been developed to diagnose and monitor asthma. We assessed the utility of MostGraph in asthmatic children.

METHODS

We evaluated 66 well controlled asthmatic children (11±3 yrs). For each subject, we measured respiratory function using MostGraph and spirometry and assessed the relationship between the two indices.

RESULTS

MostGraph measurements were significantly correlated with age and body height. R5 was remarkably associated with FEV1% by analyzing partial correlation that excluded the factor of height. In addition, R5-R20 and Fres were significantly related to FEV1% and MMF. Furthermore, R5-R20 and Fres were significantly associated with MMF through multiple regression analyses for MostGraph parameters, the height and spirometory parameters. We classified asthmatic children into two groups with 70% of V25 cut point. Group with V25 below 70% had higher scores for R5-R20, Fres and ALX, compared to group with V25 above 70%.

CONCLUSION

MostGraph could be effectively used for the R5-R20 and Fres lung function measurements to assess asthma control in children. The results also suggested that R5-R20 and Fres might be parameters of small airway dysfunction.