➤ The major trigger for bronchoconstriction in a vulnerable subject is
either water loss during periods of high ventilation or the addition of
an osmotically active agent.
➤ Exercise itself is not needed to cause bronchoconstriction, just the
creation of a hyperosmolar environment.
• The hyperosmolar environment leads to mast cell degranulation with release of
mediators, predominately leukotrienes, but also including histamine, tryptase, and
prostaglandins. In addition, eosinophils can also be activated, producing further
mediators, including leukotrienes.
➤ The water content of the inspired air, the level achieved and
maintained during exercise, or both are the major determinants of
exercise-induced bronchoconstriction (EIB).
➤ EIB is frequently documented with asthma and reflects insufficient
control of underlying asthma.
➤ Elite athletes have a higher prevalence of EIB than seen in the general
population, varying with the intensity of exercise and the environment.
➤ Summary Statement (SS)1: In asthmatic patients EIB can indicate lack
of control of the underlying asthma. Therefore treat the uncontrolled
asthma to get control of EIB. (S-D)
➤ SS2: A diagnosis of EIB should be confirmed by demonstration of
airways reversibility or challenge in association with a history consistent
with EIB because self-reported symptoms are not adequate. (S-B)
➤ SS3: Evaluate EIB in elite athletes by using objective testing. (S-B)
➤ SS4: Perform a standardized bronchoprovocation (exercise or a
surrogate) challenge to diagnose EIB because the prevalence of EIB
will vary with the type of challenge and the conditions under which the
challenge is performed. (S-A)
➤ SS5: In subjects with no current clinical history of asthma, use an
indirect ungraded challenge (eg, exercise challenge or surrogate
testing, such as with EVH) for assessing EIB in the recreational or elite
athlete who has normal lung function. (S-D)
Key Points
Diagnosis
