Exercise Induced Laryngeal Obstruction  

Randomised Control Trial

Exercise Induced Laryngeal Obstruction Randomised Control Trial

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Background for study


Traditionally the larynx has not been given very much attention in the research of respiratory problems. As a consequence, a lot of people are getting misdiagnosed with conditions such as asthma when the problem actually lies in the throat. 

In 2006, Bergen ILO group was the first to publish a method to test the larynx during exercise. This resulted in the patented Continuous Laryngoscopy Exercise (CLE)-test. With this, we were able to describe a previously unobserved problem: an apparently normal larynx could close partially or almost completely during exercise and cause severe breathing problems.

EILO in adolescents

EILO is gaining more and more recognition as a cause for breathing problems, especially in young people.

Studies show a prevalence of 5-7% in unselected adolescents, and an even higher rate in athletes. 

However, there is currently an unfortunate lack of well-designed randomised controlled studies in this area of respiratory medicine.

Study design

We will test 4 different approaches to conservative treatment in a randomised controlled design in 350 patients consecutively diagnosed with EILO at Haukeland University Hospital. The CLE-test will be used to examine the patients. The findings will be used to diagnose and subtype EILO, and to assess changes in the larynx at peak exercise before versus after interventions. 

Patients failing to improve from conservative treatment, and who otherwise qualify for surgical intervention, will be offered surgical treatment. They will be randomised into two different surgical approaches or to a “wait-and-see” control group. Trans-laryngeal resistance will be measured before and after as a secondary numerical objective outcome measure.

CLE continous laryngeal exercise test

Course of study

WestPaed Research
Universitetet i Bergen
Helse Bergen Haukeland Universitetssjukehus