Can bronchoconstriction and bronchodilatation in horses be detected using electrical impedance tomography?
- Journal Article
Summary
The research article explores if Electrical Impedance Tomography (EIT) can detect lung changes due to bronchoconstriction and bronchodilatation in horses after tests using histamine and drug treatments.
Research Objective
The goal of this study was to verify if EIT, a diagnostic technique that creates images based on changes in impedance (resistance to electrical current), could detect changes in airflow in horses’ lungs prompted by a histamine challenge and subsequent treatment with a bronchodilator.
Methodology
- The researchers caused bronchoconstriction in 17 healthy, sedated horses by administering histamine in stages.
- EIT variables were recorded before any treatment (baseline), after nebulization with saline as a control, at the histamine concentration that caused bronchoconstriction, and 2 and 10 minutes after Albuterol (a bronchodilator) administration.
- The study introduced new EIT flow variables specifically designed to evaluate changes in airflow.
- A multiple linear regression analysis was utilized to examine how EIT variables explained changes in airflow variability.
Findings
- As bronchoconstriction took effect, some EIT variables such as peak inspiratory flow (PIF), peak expiratory EIT flow (PEF), and slope of the global expiratory flow-volume curve (FV) were found to increase markedly. Furthermore, FV normalized to Tidal Volume (VT), another EIT variable, was found to decrease.
- All changes reverted to their baseline values ten minutes after Albuterol administration, suggesting successful bronchodilation.
- Interestingly, the total impedance change (a surrogate measure for tidal volume) saw no changes.
- Using multivariable analysis, the study found that a combination of PIF and PEF accounted for 51% of the variance in the change in airflow, underlining their potential as significant indicators of bronchoconstriction.
Conclusion
The research concluded that changes in airflow as a result of histamine-induced bronchoconstriction and subsequent Albuterol-induced bronchodilatation could indeed be observed using EIT through the application of specific variables. This underscores EIT’s potential as a non-invasive and valuable diagnostic tool for veterinary respiratory medicine.
Cite This Article
Publication
Researcher Affiliations
- School of Veterinary Medicine, Murdoch University, Perth, Australia.
- Systems and Computer Engineering, Carleton University, Ottawa, Canada.
- School of Veterinary Medicine, Murdoch University, Perth, Australia.
- School of Veterinary Medicine, Murdoch University, Perth, Australia.
- School of Veterinary Medicine, Murdoch University, Perth, Australia.
MeSH Terms
- Animals
- Bronchoconstriction
- Electric Impedance
- Horses
- Lung
- Tidal Volume
- Tomography, X-Ray Computed
Conflict of Interest Statement
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