Bronchial provocation testing does not detect exercise-induced laryngeal obstruction

Abstract

Inspiratory flow parameters obtained during bronchoprovocation tests did not reliably detect EILO. It remains that CLE is an important and key investigation modality in establishing a secure diagnosis of EILO.

Diagnosis of concomitant inducible laryngeal obstruction and asthma

“…19 Direct provocation challenge with histamine or methacholine has traditionally been considered to be more sensitive but less specific for asthma diagnosis. 42 The inclusion of mannitol provocation testing combined with laryngoscopy in our protocol doubled the detection rate for ILO. Other measurements obtained during bronchial provocation challenge testing, such as the mean decrease in forced inspiratory flow (%FIF 50 ) has not been found to be a reliable method of detecting (exercise induced) ILO.…”

Mechanisms, measurement and management of exertional dyspnoea in asthma

“…EILO can mimic asthma symptoms in individuals without asthma and is concurrently present in 4.8-14% of individuals with asthma, particularly in females [68,69]. Importantly, the description of dyspnoea (difficulty on inspiration), methacholine challenge and inspiratory obstruction on flow-volume loops do not accurately identify those with EILO from those without EILO, and this condition is ideally diagnosed with laryngoscopy during exercise [69].…”

“…It is also important to recognise that the studies discussed above provided no data on the reproducibility or consistency of dyspnoea descriptors in individual patients for a given stimulus. Furthermore, these dyspnoea descriptors may not be specific for asthma and could reflect concurrent laryngeal dysfunction, hyperventilation or dysfunctional breathing [69,72]. Dyspnoea quantification (using the Borg or VAS) during incremental or constant work rate cycle exercise testing may not reproduce the type of effort or correlate with symptoms encountered during activities in daily life.…”

Heredity of supraglottic exercise-induced laryngeal obstruction

“…An experienced specialist, who did not take part in performing the tests, scored the degree of EILO as none, mild, moderate or severe, using the scoring system developed by Maat and colleagues [17]. Several studies, including our previous work and the present study classify moderate and severe grades of EILO as clinically significant, and consider mild supraglottic EILO to be a variant of normal [3,7,9,10].…”

“…In recent years, the emergence of exercise laryngoscopy [4] has led to a better understanding of laryngeal movement during exercise, and inspiratory supraglottic collapse on exertion has been established as a common cause of exertional breathlessness [5] that is correlated with exercise intensity [6]. Both glottic and supraglottic inspiratory closure are more commonly seen in females and most often in adolescents or young adults [7][8][9][10][11]. This predominance has yet to be explained; however, gender differences in larynx size/growth and consequently higher "Bernoulli forces" in females for a given respiratory demand could be a contributing factor [5].…”