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Simplified Whole Body Plethysmography to Characterize Lung Function During Respiratory Melioidosis
Published on: February 24, 2023
Correlation of spirometry and body plethysmography during exercise-induced bronchial obstruction
Johannes Schulze1, Hans-Jürgen Smith2, Celine Eichhorn1
1Department for Children and Adolescents, Allergy, Pulmonology, and Cystic Fibrosis, University Hospital Frankfurt, Goethe University, Germany.
Background:
The exercise challenge is the gold standard for diagnosing exercise-induced bronchoconstriction (EIB). Airway obstructions appear up to 30 min after the challenge, with a maximum decrease in spirometry and a maximum increase in airway resistance. There is evidence that changes in body plethysmography parameters are more sensitive to the exercise challenge and precede those in spirometry.
Purpose:
To compare changes in body plethysmography and spirometry parameters after exercise challenges and to verify the cut-off values of sReff in EIB.
Procedures:
In 82 subjects with suspected EIB, a total of 473 lung function tests were measured at baseline and at 5, 10, 15, and 30 min after exercise challenges at different stages of bronchial obstruction.
Findings:
The maximum changes in the body plethysmography parameter sReff significantly preceded the maximum changes in the spirometry parameter FEV1 (sReff: 12.2 min ±8.8, FEV1: 15.2 min ±9.3, p < 0.005). The parameters of sReff and FEV1 had a strong negative correlation (r = -0.63, p < 0.0001) with a nonlinear, polynomial relationship. Furthermore, sReff and Reff had a strong linear correlation (r = 0.86, p < 0.001), and Reff and Rtot had a perfect linear correlation (r = 0.99, p < 0.001). Based on baseline values and on quantile regression, an increase of 0.25 kPa s in sReff was defined as significant. Using this cut-off value, FEV1 and sReff almost equally detected EIB.
Conclusion:
The changes in sReff were more sensitive and better indicated lung impairment than did the changes in FEV1, which underestimated the degree of hyperinflation.
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