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"Reactance inversion" at low frequencies in a child undergoing treatment of a cystic fibrosis exacerbation

Julian Lewis Allen1, Clement L Ren2, Joseph McDonough1

  • 1Division of Pulmonary Medicine The Children's Hospital of Philadelphia Philadelphia PA USA.

Pediatric Investigation
|August 28, 2020
PubMed

Insights

Impulse oscillometry (IOS) revealed improved respiratory mechanics in a child with cystic fibrosis (CF) after treatment. A novel finding of "reactance inversion" was observed in this young patient.

Area of Science:

  • Pediatric Pulmonology
  • Respiratory Physiology
  • Medical Technology

Background:

  • Impulse oscillometry (IOS) assesses respiratory system mechanics using pressure and flow waveforms.
  • IOS is valuable for young children unable to perform spirometry.

Observation:

  • A case study of a 6-year-old child with cystic fibrosis (CF) is presented.
  • The child showed clinical and radiological improvement after antibiotic therapy and CFTR modulator treatment.
  • Impulse oscillometry (IOS) was used to measure changes in respiratory system mechanics.

Findings:

  • Respiratory system mechanics improved following treatment in the pediatric CF patient.
  • A novel finding termed "reactance inversion" (lower reactance at low vs. high frequencies) was observed.
  • Reactance inversion may suggest parallel pathway inhomogeneities or intrabreath airway inertance changes.

Implications:

  • Reactance inversion might be a specific indicator in young children with CF and airway obstruction.
  • Further research is needed to confirm the prevalence and device specificity of reactance inversion.
  • This finding could enhance the diagnostic utility of IOS in pediatric lung diseases like asthma and CF.
Abstract

Keywords:
Cystic fibrosisExacerbationImpulse oscillometryReactanceReactance inversion

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