Spirometry - a tool for diagnosing exercise induced laryngeal obstruction (EILO)?

Introduction Exercise Induced Inspiratory Symptoms (EIIS) are often confused with those of asthma, and increasingly recognized as a problem in otherwise healthy young people. EIIS is often associated with Exercise Induced Laryngeal Obstruction (EILO), involving supraglottic adduction in a majority. Flattened or truncated maximal inspiratory flow volume loops (MIFVL) have been suggested as indicative of EILO, thus a laryngeal obstruction should be expected during this procedure. Aim Study to what extent supraglottic laryngoscopic findings obtained at MIFVL maneuvers at rest correspond with similar findings during continuous laryngoscopy exercise (CLE) test. Methods Video recordings from 2012-2013 were analyzed for supraglottic laryngeal adduction during MIFVL maneuvers and CLE-tests, applying Maat-score1 (mild, moderate, severe). Results 189/198 CLE-test recordings were technically adequate, 111/189 were considered positive with moderate or severe supraglottic adduction. MIFVL maneuvers at rest resulted in no or mild supraglottic adduction in 143 (76%) patients, of whom 70 scored worse during CLE test with moderate or severe supraglottic adduction. MIFVL procedures resulted in moderate or severe supraglottic adduction in 46 patients, of whom 5 scored lower during CLE test with no or mild supraglottic adduction. In patients with moderate or severe supraglottic adduction during CLE-test, only 37% had similar findings during MIFVL procedures. Conclusion Correlations between supraglottic adduction at MIFVL maneuvers and during CLE tests were poor. Thus, spirometry should be used with caution as a diagnostic tool in relation to EIIS and EILO. 1 Maat RC et.al. Eur Arch Otorhinolaryngol 2009 .