Comparison of changes in lung function measured by plethymography and IOS after bronchoprovocation

Area of Science:

• Pulmonology
• Respiratory Medicine
• Allergy and Immunology

Background:

• Lung function tests are crucial for diagnosing and managing bronchial asthma.
• Impulse oscillation system (IOS) provides an alternative method for assessing lung mechanics.
• Comparing the sensitivity of different lung function tests is essential for optimal clinical practice.

Purpose of the Study:

• To compare the sensitivity of impulse oscillation system (IOS), body plethysmography, and spirometry in detecting allergen- and methacholine-induced bronchoconstriction.
• To evaluate IOS as a potential alternative to traditional lung function tests.

Main Methods:

• Twenty-two subjects with mild allergic asthma underwent allergen inhalation challenges.
• Eight subjects underwent methacholine challenges.
• Lung function was measured using IOS, body plethysmography, and spirometry, with tests stopping at a 20% fall in FEV1.

Main Results:

• Following allergen challenges, IOS index R5-R20 was most sensitive.
• Following methacholine challenge, IOS index AX was most sensitive.
• Overall, IOS demonstrated higher sensitivity than plethysmography and spirometry in detecting induced bronchoconstriction.

Conclusions:

• Impulse oscillation system (IOS) is more sensitive than spirometry and plethysmography for detecting allergen- and methacholine-induced bronchoconstriction.
• IOS serves as a valuable alternative for measuring airway resistance and obstruction, especially in patients who find spirometry and plethysmography challenging.