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Exercise-Induced Bronchospasm
Jonathan P. Parsons, MD, MSc
Associate Professor of Internal Medicine
Division of Pulmonary and Critical Care Medicine
Associate Director, The Ohio State University Asthma Center
Learning Objectives
Be able to define exercise-induced bronchospasm (EIB)
Discuss the epidemiology/public health burden of EIB
Explain the pathophysiology of EIB
Describe the typical clinical presentation of EIB
Discuss the diagnostic challenges in patients with EIB
Outline the treatment of EIB
At the end of the module, you will know the following:
Bronchospasm
Normal Bronchiole Bronchiole during EIB attack
Smooth muscle hypertrophy
Narrow airway lumenNormal
airway lumen
Normal smooth muscle layer
Definition of EIB
EIB is simply defined as airway narrowing or bronchospasm that occurs in association with exercise.
EIB is specifically and objectively defined as a decline in lung function of > 10% from baseline after appropriate testing
EIB can occur during exercise, but happens more commonly after an exercise session is over
Prevalence of EIB in patients with asthma
Exercise is one of the most common triggers of bronchospasm in patients with chronic asthma
80-90% of patients with chronic asthma will experience EIB
4%14%
3%3%3%3%4%
6%6%7%
9%9%10%
12%16%
19%19%
31%32%
0% 20% 40% 60%
Not SureOther
PollutionEmotions
StressCold air
Mold/mildewAllergies
Fumes or odorsPerfume
ChemicalsGrass
Tobacco smokeViruses or colds
AnimalsDust (mites)
PollenWeather changes
Exercise
Common triggers of bronchospasm in patients with asthma
Parsons JP et al. Allergy Asthma Proc. 2011 Nov-Dec;32(6):431-7.
Prevalence of EIB in general population
EIB also occurs in up to 10-15% of the general population without chronic asthma.
These are patients whose sole trigger of bronchospasm is exercise.
“but I don’t have asthma” “you can still
have EIB”
Prevalence in Athletes
There is a significant prevalence of EIB in athletes • Studies have reported prevalence rates ranging from
10-50% depending on population studied
Some studies suggest that certain sports may have higher relative risk of EIB• cold weather sports (i.e. cross-country skiing)• high-aerobic demand sports (i.e. soccer, distance
running)• sports with environmental exposures (i.e. chlorine
fumes in swimming, poor air quality in ice rinks)
39%46%
26%
0%
20%
40%
60%
80%
100%
TOTAL Adult Child
Burden of EIB
Parsons JP et al. Allergy Asthma Proc. 2011 Nov-Dec;32(6):431-7.
Do you avoid physical activity due to EIB?
% t
hat
answ
ered
yes
Survey population: 1000 adults and 500 children with asthma
Burden of EIB
6%9%
6% 5%
19%
13%
25%21% 19%
52%
0%
20%
40%
60%
80%
100%
Isolated or alone Fearful Depressed Embarrassed Frustrated
EIB negative EIB positive
% t
hat
answ
ered
yes
Parsons JP et al. Allergy Asthma Proc. 2011 Nov-Dec;32(6):431-7.
Health Limits Activities: A Lot or Some
52% 52%
44% 42%
20% 19%16% 17%
0%
20%
40%
60%
80%
100%
Sports & recreation Outdoor activities, like biking or hiking
Going to the gym or exercising
Normal physical exertion
EIB-positive EIB-negative
Parsons JP et al. Allergy Asthma Proc. 2011 Nov-Dec;32(6):431-7.
Parsons JP et al. Allergy Asthma Proc. 2011 Nov-Dec;32(6):431-7.
Pathophysiology of EIB
Elsevier, Inc.
Pathophysiology of EIB
There is strong evidence that
mediators from mast cells and eosinophils are
released into the airways during EIB
This mediator release is
hypothesized to be the predominant
cause of EIB
Pathophysiology of EIB
Exercise-Induced Bronchospasm
020406080
100120140
0 10 20 30 40 50 60 70
Time (min)
% B
asel
ine
Air
flow
Peak bronchospasm
Bronchodilation
Airflow in EIB
EIB (+)
EIB (-) Exercise
Typical clinical presentation
Presenting Symptoms of EIB
Common
• Cough• Shortness of
breath• Fatigue• Chest tightness• Wheezing
More subtle
• Poor performance for conditioning level
• Avoidance of activity
• Symptoms in specific environments
Mild impairment of performance
Severe bronchospasm/risk of
respiratory failure
Diagnostic challenges in EIB
High index of suspicion required as symptoms can be subtle and non-specific
Symptoms of EIB are frequently mistaken as normal manifestations of exercise.
Many patients are very poor perceivers of symptoms of bronchospasm
Competitive athletes are often stubborn
Objective confirmation of suspected EIB is essential.
Parsons JP et al. Med Sci Sports Exerc. 2007
Diagnosis of EIB
Spirometry
Commonly will be normal
Normal spirometry at rest does not
rule out EIB
Electrocardiogram (ECG)
Wolff-Parkinson-White
Long QT
Chamber enlargement
Bronchoprovocation Testing
Eucapnic Voluntary
Hyperventilation (EVH) testing
Exercise Challenge
Eucapnic Voluntary Hyperventilation (EVH)
Preferred test to document need for bronchodilators during competition for Olympians.
More sensitive and specific in some studies than other methods of bronchoprovocation.
Involves breathing a 5% CO2 gas mixture 30 times per minute for 6 minutes.• Increased CO2 prevents
• Syncope• Further bronchoconstriction
Anderson, SD et al. JACI. 111:45-50, 2003.Holzer, K. et al. Clin.J.Sport Med. 14:134-138, 2004.
Mannix, ET et al Chest. 115:649-653, 1999.
EVH Testing
Anderson, S. D et. Br J Sports Med. 35:344-347, 2001.
At the completion of 6 minutes of hyperventilation, spirometry is performed at 3, 5, 10, 15, and 20 minute intervals after EVH.
A positive response is a decline of > 10% from baseline lung function at any time-point after EVH.
EVH equipment
EVH test
Exercise Challenge
Several studies have shown that EVH is superior to lab- or field-based exercise challenge for diagnosis of EIB• However, exercise testing is
widely available• Probably your next best test
currently available if no EVH• Important to assess serial
spirometry up to 20 minutes after the exercise session
Mannix et al. 1999.. Chest 115(3):649-653.Holzer, K., and P. Brukner. 2004.. Clin.J.Sport Med. 14(3):134-138.
Anderson et al. Med Sci Sports Exerc. 40(9):1567-1572
Treatment of EIB
First-line therapy is prophylactic use of short-acting bronchodilators such as albuterol shortly before exercise.• Two to four puffs taken 15 minutes before
exercise provides about 4 hours of relief
• 80% effective
Treatment of EIB
Inhaled corticosteroids are effective.• daily medicine• used for 4 weeks or more before effects seen
Montelukast (a leukotriene modifier taken orally) also has been shown to be effective in treating EIB• Must be taken 2 hours prior to exercise
Treatment of EIB
Adequate warm-up prior to exercise allows athletes to often take advantage of the “refractory period.”• interval in which a relative reduction in bronchospasm
occurs. • begins 30-90 minutes after exercise is initiated and
may be due to:• release of catecholamines• depletion of inflammatory mediators
• Present in 50% of patients with EIB• Unable to predict who will have refractory period or the
degree of protection
Non-Pharmacologic Approaches
Face mask• The wearing of a face mask during activities in dry, cold air allows
the air to be warmed up and humidified.
Avoidance of allergen• Athletes with allergies should avoid exposure to allergens as
much as possible.
Nutritional approach• omega-3 polyunsaturated fatty acids • antioxidant intake • sodium restricted diet
• Very preliminary data
Exercise Induced Bronchospasm
Thank you!
I hope that I was able to teach the subject clearly.
If you have any questions, write to me: [email protected]
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