Asthma (Diagnosis)
Conditions
Keywords
lung function testing, oscillometry, asthma
Brief summary
Oscillometry is a pulmonary function testing technique suited for children because it does not require specific respiratory maneuvers like spirometry. Oscillometry provides a measure of respiratory impedance (Zrs) that is underestimated when the oscillatory signal is applied at the subject's mouth particularly during bronchoconstriction induced by an exercise challenge test (ECT). This limitation may be overcome by calculating respiratory admittance (Ars), the inverse of respiratory impedance during an ECT.
Detailed description
Oscillometry is a pulmonary function testing technique that is well suited to children who have difficulty cooperating with conventional tests such as spirometry, as it is performed during spontaneous breathing and does not require specific respiratory maneuvers. In contrast, spirometry requires a deep inspiration followed by a forced and complete expiration. Oscillometry provides a measure of respiratory impedance, which is the complex sum of respiratory resistance (Rrs) and respiratory reactance (Xrs). However, when the oscillatory signal is applied directly at the subject's airway opening, part of the flow signal may be lost due to cheek wall vibrations, resulting in an underestimation of Rrs. This underestimation may be more pronounced during bronchoconstriction, such as that induced by an exercise challenge test (ECT). This limitation may be overcome by calculating respiratory admittance (Ars), the inverse of respiratory impedance. When calculating the response to ECT, cheek wall admittance is cancelled out, potentially allowing a more accurate assessment of changes in respiratory mechanics during an ECT. The hypothesis was that calculating Ars provides a more accurate assessment of changes in airway mechanics during an ECT.
Interventions
None listed
Sponsors
Central Hospital, Nancy, France
Study design
Observational model
COHORT
Time perspective
RETROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
5 Years to 16 Years
Healthy volunteers
No
Inclusion criteria
* Children aged 5 to 16 years * Children addressed by the pediatric pulmonologist to an exercise challenge test between January 2023 and April 2026 * Children with interpretable and reproducible oscillometric measurements * Children with interpretable and reproducible spirometric measurements
Exclusion criteria
* Children who performed only spirometric measurements * Children who performed only oscillometric measurements * Children whose oscillometric and spirometric measurements are non-interpretable * Children whose oscillometric and spirometric measurements are non-reproducible
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Diagnostic performance of Ars | Through study completion, an average of 1 month | Area under the ROC curves (AUC) for response to exercise challenge of Ars (computed from oscillometric parameters) compared with AUC of respiratory resistance to identify children with a positive challenge test and children with a negative challenge test |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Sensitivity of Ars | Through study completion, an average of 1 month | Sensitivity of the response to exercise challenge of Ars (computed from oscillometric parameters) compared with the sensitivity of respiratory resistance to identify children with a positive challenge test |
| Specificity of Ars | Through study completion, an average of 1 month | Specificity of the response to exercise challenge of Ars (computed from oscillometric parameters) compared with the specificity of respiratory resistance to identify children with a positive challenge test |
Contacts
CONTACTIulia Ioan, MD PhD
Outcome results
None listed