Intra-breath oscillometry has been proposed as a more sensitive measure of airway obstruction and respiratory mechanics compared to conventional spectral oscillometry outcomes in children with recurrent wheeze. It is unknown whether intra-breath oscillometry detects airway obstruction in children born preterm. We aimed to assess intra-breath and spectral oscillometry measures in preterm and term-born children.
Spectral and intra-breath oscillometry was measured using the tremoflo device (Thorasys Inc. Montreal, QC) before and after 400 µg salbutamol in children born very preterm (<32 weeks gestation) and at term (>37 weeks gestation); aged 6-12 years.
Oscillometry was measured at a mean age of 10.6 years in 20 term-born and 65 preterm-born children, of whom 15 had a neonatal diagnosis of bronchopulmonary dysplasia. At baseline, spectral oscillometry measures (R5, X5 and AX) were significantly different between preterm- and term-born children, however intra-breath outcomes (∆R10, ∆X10) were not (Table 1). A significant bronchodilator response (-32% or greater change in R5) was present in 20/65 (30.7%) preterm-born children and 4/20 (20.0%) term-born children (p>0.05).
Spectral oscillometry differentiated preterm from term-born children, whereas intra-breath measures did not.