1. 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

2. Learning Objectives
At the end of the module, you will know the following:
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
the diagnostic challenges in patients with EIB
Outline
the treatment of EIB

3. Bronchospasm Normal smooth muscle layer Smooth muscle hypertrophy
Narrow
airway lumen
Normal
airway lumen
Normal Bronchiole Bronchiole during EIB attack

4. 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

5. 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

6. Common triggers of bronchospasm in patients with asthma
Parsons JP et al. Allergy Asthma Proc Nov-Dec;32(6):431-7.

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”

8. 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)

9. Burden of EIB Do you avoid physical activity due to EIB?
% that answered yes
Survey population: adults and 500 children with asthma
Parsons JP et al. Allergy Asthma Proc Nov-Dec;32(6):431-7.

10. Burden of EIB % that answered yes
Parsons JP et al. Allergy Asthma Proc Nov-Dec;32(6):431-7.

11. Health Limits Activities: A Lot or Some
Parsons JP et al. Allergy Asthma Proc Nov-Dec;32(6):431-7.
Parsons JP et al. Allergy Asthma Proc Nov-Dec;32(6):431-7.

12. Pathophysiology of EIB
Elsevier, Inc.

13. 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

14. Pathophysiology of EIB

15. Typical clinical presentation
Bronchodilation
EIB (+)
EIB (-)
Exercise
Peak
bronchospasm
Airflow in EIB

16. 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

17. 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

18. 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

19. 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: , 2004.
Mannix, ET et al Chest. 115: , 1999.

20. EVH Testing
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.
Anderson, S. D et. Br J Sports Med. 35: , 2001.

21. EVH equipment

22. EVH test

23. 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 Chest 115(3):
Holzer, K., and P. Brukner Clin.J.Sport Med. 14(3):
Anderson et al. Med Sci Sports Exerc. 40(9):

24. 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

25. 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

26. 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 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

27. 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

28. Exercise Induced Bronchospasm

29. Thank you! I hope that I was able to teach the subject clearly.
If you have any questions, write to me:

30. Survey
We would appreciate your feedback on this module. Click on the button below to complete a brief survey. Your responses and comments will be shared with the module’s author, the LSI EdTech team, and LSI curriculum leaders. We will use your feedback to improve future versions of the module. The survey is both optional and anonymous and should take less than 5 minutes to complete.
Survey