Reliability of translaryngeal airway resistance measurements during maximal exercise

Abstract

Objective: Exercised induced laryngeal obstruction (EILO) is an important cause of exertional dyspnea. The diagnosis rests on visual judgement of relative changes of the laryngeal inlet during continuous laryngoscopy exercise (CLE) tests, but we lack objective measures that reflect functional consequences. We aimed to investigate repeatability and normal values of trans-laryngeal airway resistance measured at maximal intensity exercise.Methods: Thirty-one healthy non-smokers without exercise related breathing problems were recruited. Participants performed two CLE tests enabling verified positioning of two pressure sensors, one at the tip of the epiglottis (supraglottic) and one by the fifth tracheal ring (subglottic). Airway pressure and flow data were continuously collected breath-by-breath and used to calculate trans-laryngeal resistance at peak exercise. Laryngeal obstruction was assessed according to a standardised CLE-score system.Results: Data from 26 participants (16 females) with two successful tests and equal CLE scores on both test-sessions were included in the trans-laryngeal resistance repeatability analyses. The coefficient of repeatability (CR) was 0.62 cmH2O·L−1·s−1, corresponding to a CR% of 21%. Mean (sd) trans-laryngeal airway resistance (cmH2O·L−1·s−1) in participants with no laryngeal obstruction (n=15) was 2.88 (0.50) in females and 2.18 (0.50) in males. Higher CLE scores correlated with higher trans-laryngeal resistance in females (r=0.81, p<0.001).Conclusions: This study establishes trans-laryngeal airway resistance obtained during exercise as a reliable parameter in respiratory medicine, opening the door for more informed treatment decisions and future research on the role of the larynx in health and disease.

Laryngeal response to high-intensity exercise in healthy athletes

“…In the future, measuring translaryngeal resistance may be of assistance in diagnostic evaluations, as it provides an objective functional measure, contrasting the solely visual impression provided by the CLE test. 6 23 …”

“… 4 While the pathophysiology is poorly understood, the increased airflow induced by the high-volume ventilation required to perform exercise, somehow triggers the paradoxical adduction we can observe in the laryngoscope. 6 There is currently consensus that we should distinguish between EILO with predominantly glottic and supraglottic obstruction, as these might represent different phenotypes. 5 7 Some few studies have suggested how the larynx normally should respond to exercise in non-athletes.…”

Prevalence and impact of exercise-induced laryngeal obstruction in asthma: a study protocol for a cross-sectional and longitudinal study

“…Similarly, Christensen et al found laryngeal obstruction in 7.6% of their invited adolescents and young adults 7. To further complicate this topic, the cut-off for what should be considered pathological laryngeal adduction has not been settled,17 and various degrees of laryngeal adduction have repeatedly been reported in individuals who do not necessarily complain of respiratory problems during exercise 18 19…”