Abstract:
Introduction: The European Respiratory Society Oscillometry
Taskforce identified that clinical correlates of bronchodilator
responses are needed to advance oscillometry in clinical practice. The
understanding of bronchodilator-induced oscillometry changes in preterm
lung disease is poor. Here we describe a comparison of bronchodilator
assessments performed using oscillometry and spirometry in a population
born very preterm and explore the relationship between
bronchodilator-induced changes in respiratory function and clinical
outcomes.
Methods: Participants aged 6-23 born ≤32 (N=288; 132 with
bronchopulmonary dysplasia) and ≥37 weeks’ gestation (N=76, term-born
controls) performed spirometry and oscillometry. A significant
bronchodilator response (BDR) to 400mcg salbutamol was classified
according to published criteria.
Results: A BDR was identified in 30.9% (n=85) of preterm-born
individuals via spirometry and/or oscillometry, with poor agreement
between spirometry and oscillometry definitions (k=0.26; 95%CI 0.18 to
0.40, p<0.001). Those born preterm with a BDR by oscillometry
but not spirometry had increased wheeze (33% vs 11%, p=0.010) and
baseline resistance (Rrs5 z-score mean difference (MD)=
0.86, 95%CI 0.07 to 1.65, p=0.025), but similar spirometry to the group
without a BDR (FEV1 z-score MD= -0.01, 95%CI -0.66 to
0.68, p>0.999). Oscillometry was more feasible than
spirometry (95% vs 85% (FEV1), 69% (FVC),
p<0.001), however being born preterm did not affect test
feasibility.
Conclusion: In the preterm population, oscillometry is a
feasible and clinically useful supportive test to assess the airway
response to inhaled salbutamol. Changes measured by oscillometry reflect
related but distinct physiological changes to that measured by
spirometry and thus these tests should not be used interchangeably.