Respiratory reactance in children aged three to five years with postinfectious bronchiolitis obliterans is higher than in those with asthma.

AIM

We investigated airway function in preschoolers with postinfectious bronchiolitis obliterans (PIBO) using impulse oscillometry (IOS).

METHODS

This study enrolled 182 children aged three to five years: 12 with PIBO, 135 with asthma and 35 nonatopic controls. Respiratory resistance and reactance were assessed using IOS.

RESULTS

The percentage predicted (% predicted) of prebronchodilator respiratory resistance at 5 Hz was significantly higher in children with PIBO (177.9 ± 118.4%) than the asthma (126.1 ± 30.5%, p = 0.013) or control (121.1 ± 21.8%, p = 0.014) groups. After bronchodilator use, children with PIBO did not reach the values of Rrs5% predicted in the asthma and control groups. Respiratory reactance (Xrs5% predicted) in children with PIBO (337.1 ± 478.5%) was significantly higher than both asthma (130.0 ± 80.0%, p = 0.004) and control (105.1 ± 30.8%, p < 0.001) groups before bronchodilator use and significantly higher than the two groups after bronchodilator use (p = 0.010 and p = 0.004, respectively). The changes in Rrs5 and Xrs5 were not significantly different between the children with PIBO and asthma.

CONCLUSION

Measuring Rrs5 and Xrs5 before and after bronchodilator use may help to discriminate PIBO from asthma in children aged three to five years with chronic or recurrent respiratory symptoms.