Exercise-Induced Laryngeal Obstruction (EILO) while breathing cold air

Abstract

Introduction: Exercise-induced laryngeal obstruction (EILO) is important to consider when investigating patients with exercise-induced dyspnea. The gold standard in EILO-diagnostics is the Continuous Laryngoscopy Exercise test (CLE test), visualizing laryngeal response patterns during a standardized treadmill exercise test with increasing workload until maximal effort. Although literature reports more symptoms of EILO during exercise in cold air, compared to room air, no studies have systematically investigated a potential difference. Aims: To evaluate a potential difference in laryngeal obstruction when breathing cold air compared to room air, among young adults (suspected of EILO. Methods: In this randomized crossover design, nine patients (29.8 (21-38) years (mean (range)) suspected of having EILO were included. They performed, in random order, two standard CLE tests, one while breathing cold air (-15°C) and one while breathing room air (20-22°C). The degree of laryngeal closure was scored using standard CLE score at moderate and maximal effort on glottic, and supraglottic level. A higher CLE score indicates more laryngeal closure. Results: There was no difference in the CLE sum score (0.1(-0.7-0.5) (mean difference (95%confidence interval (CI)). When breathing cold air during the CLE tests, the mean difference in test duration were 15 seconds shorter (2-28 (95%CI)), and the supraglottic closure at moderate effort was higher at an identical workload (0.6 (0.2-1) (mean difference (95%CI)), compared to when breathing room air. Conclusion: Breathing cold air compared to room air did not influence the CLE sum score. The patients ran for a shorter period when breathing cold air, and supraglottic obstruction was more prominent at moderate effort. More extensive studies with more patients are needed.