Airflow through the supraglottis during inspiration.

Area of Science:

• Sports Medicine
• Respiratory Physiology
• Biomedical Engineering

Background:

• Exercise-induced laryngeal obstruction (EILO) is a condition causing airway narrowing during physical activity.
• Supraglottic closure is the most frequent type of laryngeal obstruction observed in athletes.
• Understanding the biomechanics of EILO is crucial for developing effective interventions.

Purpose of the Study:

• To investigate the airflow dynamics and pressure distribution within the larynx during high-intensity exercise.
• To model the air-induced loads on the supraglottis and their role in laryngeal collapse.
• To elucidate the relationship between inspiratory flow rates and pressure differentials in the hypopharynx and supraglottis.

Main Methods:

• Development of a computational fluid dynamics (CFD) model of the human larynx.
• Simulation of inspiratory airflow at various high-intensity exercise-related flow rates.
• Analysis of airflow velocity, pressure, and wall-induced loads on the supraglottic region.

Main Results:

• Positive wall pressure was observed in the hypopharynx at high flow rates.
• Posterior supraglottic wall pressures transitioned from positive to negative.
• Significant pressure differentials were identified across the supraglottis at elevated inspiratory flow rates.

Conclusions:

• High inspiratory flow rates during intense exercise can generate critical pressure differentials within the larynx.
• These pressure differentials are a likely contributing factor to supraglottic collapse in EILO.
• CFD modeling provides valuable insights into the mechanisms underlying exercise-induced laryngeal obstruction.