Cut-off values to evaluate exercise-induced asthma in eucapnic voluntary hyperventilation test for children.

Area of Science:

• Pediatric Pulmonology
• Diagnostic Testing
• Respiratory Medicine

Background:

• Exercise-induced bronchoconstriction (EIB) is common in children.
• Eucapnic voluntary hyperventilation (EVH) is a diagnostic tool for EIB.
• Limited data exist on EVH feasibility and efficacy in pediatric populations.

Purpose of the Study:

• To assess the feasibility of EVH testing in children aged 10-16 years.
• To determine optimal diagnostic cut-off values for EVH testing in children.
• To identify factors influencing EVH testing outcomes in pediatric patients.

Main Methods:

• 134 children (10-16 years) with exercise-induced dyspnea and 100 healthy controls underwent 6-minute EVH testing.
• Feasibility was determined by achieving ≥70% of target minute ventilation (30 x FEV1).
• Bronchoconstriction was defined by a fall in FEV1 (≥8%, 10%, 12%, 15%, or 20%); patient characteristics were correlated with outcomes.

Main Results:

• 98% of children achieved ≥70% of target ventilation, indicating high feasibility.
• Children with exercise-induced dyspnea showed significantly higher FEV1 fall percentages compared to controls.
• Healthy controls and boys achieved higher ventilation rates during testing.

Conclusions:

• EVH testing is feasible and diagnostically valuable for exercise-induced dyspnea in children (10-16 years).
• A minimum 10% fall in FEV1 is a recommended diagnostic cut-off.
• Disease status is an important factor influencing EVH test results.