Sports Medicine

Mario Cesar Moreira de Araujo, MD & Marcelo Riccio Facio, MD

Medstudents' Homepage

Exercise Induced Bronchoconstriction (EIB) - Part 2



Less-Tolerated Sports

1. scuba diving
2. cross country skiing
3. ice hockey
4. basketball
5. field hockey
6. soccer

Cold weather events, such as skiing and ice hockey or long-distance, non-stop activities like basketball, field hockey or soccer are more likely to aggravate airways. In general, short duration activities with built-in rest periods are less likely to cause asthma symptoms than endurance-type activities with sustained exertion; i.e. interval training consisting of short periods of exercise for 5-7 minutes, as in gymnastics or games for example, with intervening periods of relaxation or rest (but without complete recovery) is usually preferred to endurance. The rest interval may need to be lengthened for children who need more time to recover.

Any continuous exercise that is less than 4-6 minutes in duration should not invoke EIB. However, it is important to remember that in the majority of children with asthma or EIB, pretreatment with proper drugs may allow them to participate in any activity they choose.

Following an initial warm-up, a work load should be chosen that can be tolerated for 10-15 minutes. With improved tolerance to exercise, the stress should be gradually increased and prolonged to approximately 60minutes or the length of the lesson. This could be swimming, running or games depending on the nature of the physical education lesson. The intensity of exercise should start at low level and gradually increase to develop exercise tolerance. Learning a new sport or replacing one activity for another activity may be an option.

Symptoms of EIB

EIB is often overlooked by parents, physicians,and coaches. It should be diagnosed early for an adequate intervention , if not athletes continues to have Symptoms and very soon they may be limit to practice sports.

Common signs and Symptoms found in EIB :

Wheezing, shortness of breath on exertion, chest tightness, cough after a jogging or playing, chest congestion, chest discomfort or pain, feels out of shape or winded, tires easily, problems occurs while running but not while swimming, dizziness, stomach-ache, and frequent colds.

Three Stages Have Been Identified in EIB

1. Early Phase : It is the most severe stage and may occurs during exercise but most frequently begins after 6 - 8 min. of vigorous exercise. The peak of bronchoconstriction is around the tenth minute and it lasts 30 - 60 min.
2. Refractory Period (Grace Period) : In about 50% of patients with EIB , there is a period which little or no bronchoconstriction is present. This phase occurs after the initial bout of EIB and lasts for 30-90 min. If the athlete was well informed by physician , he can take advantage of this phase for best results.
3. Late Phase : Symptoms can occur again, beginning 12-16 hours after exercise and resolve within 24 hours. This phase is a less severe stage and it may or may not occur.

Diagnosing EIB

The clinical diagnoses is the most important to identify EIB. The occurrence of the Symptoms listed above is the first glue to identify the disease . A careful physical examination of the upper and lower respiratory tracts is very important , although it often could be normal , due to episodic nature of EIB. Inflammatory process found in airways can be suggestive of EIB.

Pulmonary function testing is essential to EIB diagnoses.FEV1 and FEV1/FVC values below 80% of predictive value indicate obstructive airways disease. However , many patients have Symptoms of EIB, but a normal resting pulmonary function test, so bronchoprovocation test and Exercise challenge test are necessaries. In general, bronchoprovocation testing is more sensitive than exercise challenge , but this are much more specific for EIB than that. It is advisable to have a good sensitivity and specificity that booth were made.

.In exercise challenge testing a postexercise decreases of 10% to 20% in FEV1 indicate mild EIA, 20% to 40 % moderate and more than 40% severe.

Treatment of EIB

1) Nonpharmacologic interventions

The goal of EIB management is to allow patients to participate fully in athletic activities without difficulty. At table 1 are listed the goals of nonpharmacologic intervention:

Table 1

Activity Modification
  • Increase physical conditioning
  • Short bursts of activity
  • Warm up activities , to take advantage of refractory period
    • Improvement in ambient air conditions
  • Avoid exercises on dry and cold air
  • Wear a face mask when outdoors conditions are cold and dry
  • Breath through the nose rather than the mouse to warm and humidify the air
    • Patient education
  • Be aware of the condition that exacerbated the disease
  • Appropriate use of medications

    • 2) Pharmacologic interventions

    Several classes of drugs with bronchodilating and anti-inflammatory characteristics are used to treat EIB.

    I. Beta agonists. These are the drugs of choice for preventing EIB. The short acting agents (albuterol, bitolterol mesylate, metaproterenol sulphate) are the most effective to prevent to prevent the attacks in 80% to 95% of patients. They should be used inhaled and have a rapid onset of action, usually within 5 min., having maximal bronchodilator effect usually within 15 min. So , short acting agents should be administered 15 min. before exercise. Salmetarol , a long acting agent has been shown to protect against EIB for 12 hours in 55% of patients. However , it has his onset of action slower than short acting agents, and it is never to be used as a rescue medication.
    II. Cromolyn sodium. Its anti-inflammatory effects prevent EIB in 70%-80% of patients. It is most effective in patients with normal pulmonary function tests and are very useful , associated with beta agonists, in patients who don’t respond to single-medication therapy.
    III. Corticosteroids. Administrated through an inhaler improve asthma Symptoms by reducing airway inflammation and bronchial hyperreavtivity. They don’t have any immediate bronchodilator effect and are not effective if used alone just prior to exercise. They should be used as a maintenance therapy to control EIB. Such use can improve the effectiveness of pre-exercise beta agonist in preventing or decreasing the severity of EIB. Inhaled dosages of less than 400g daily have a low incidence of side effects . When side effects occur , the most common are oropharyngeal candidiasis and dysphonia.
    IV. Oral theophyllin has been widely used in the treatment of asthma for decades. Its bronchodilator effects are directly related to plasma concentration, and theophyllin may also have some anti-inflammatory effects . Theophyllin is not a first-line agent in the prevention and treatment of EIB-it is generally used for patients who do not respond well to inhaled beta agonists. Theophyllin would be a third choice behind beta agonists and cromolyn for patients under age 12, and would rank behind beta agonists, cromolyn or nedocromil, and perhaps ipratropium bromide in those over age 12. Theophyllin may be given either in rapid-release form 1 to 2 hours before exercise or regularly in the sustained-release form for prophylaxis. Even in rapid-release form, theophyllin’s long onset of action (approximately 90 minutes) limits its use in an athletic setting . Factors influencing serum concentration and the possible effect on classroom concentration in children make theophyllin less desirable than other options in most patients. As with cromolyn sodium, the combination of theophyllin and a beta agonist may be additive in the prevention of EIB , though concerns have been raised regarding increased incidence of side effects when these two agents are used together .
    V. Ipratropium bromide is a derivative of atropine and has bronchodilator effects. The inhaled drug is used in some patients with EIB who are unable to tolerate or who do not respond well to beta agonists. It may also be used in combination with beta agonists or cromolyn sodium. If cromolyn or nedocromil combined with a beta agonist do not adequately control bronchospasm, a trial of ipratropium bromide would be recommended. The drug has a slower onset of action than beta agonists, and its use in EIB is limited: When used alone, the drug is effective in only 30% to 40% of patients and requires nearly normal baseline pulmonary function to be effective . When combined with a beta agonist, ipratropium bromide may be a helpful adjunct in adults who have moderate-to-severe asthma. Though some studies have reported effective prophylaxis of EIB with ipratropium bromide, others have not found it to be effective .
    VI. Other agents that have been used in the treatment of EIB include antihistamines and calcium channel blockers. Antihistamines decrease bronchospasm in some individuals but will not prevent EIB. However, they can improve nasal function, allowing the patient to breathe better through his or her nose. The calcium channel blockers nifedipine and verapamil hydrochloride have been shown to inhibit mast cell mediator release and prevent symptoms of EIB in a select group of patients ; however, data are insufficient to recommend them for EIB control.

    Recent studies report that leukotriene inhibitors and heparin relieve EIB. The clinical effectiveness and use of these medicines will become more apparent after further trials.

    Value of Exercise

    · Increased exercise tolerance · Improved self esteem · Increased confidence · Improved psychological and physical well-being

    Regular physical education, while not a cure for asthma, increases fitness and if undertaken appropriately, can result in less troublesome EIB. The inability to participate in athletic programs and/or recreational sports can be a handicap for children and adults alike.

    For years it was thought that asthmatics could not and should not take part in team sports and vigorous activities. We now know that this is not correct. Exercise improves a child’s self esteem, confidence, psychological and physical well-being; most children with well controlled asthma can participate in regular physical activities and exercise programs with minimal difficulties.

    Today, with proper detection and treatment, those affected by asthma can be capable of exercise that’s beneficial to both their physical health as well as their emotional well-being.Children will have different levels of tolerance to exercise; individual teaching and education can be done so children learn to pace themselves in order to participate at their appropriate levels.

    Even with optimal conditions, however, highly strenuous exercise can provoke EIB in some individuals; obviously there is no substitute for good judgement.

    The “Situation”: Vicious Cycle of Inactivity

    A vicious cycle is often seen in people with breathing problems. Children with asthma may feel breathless, or show other signs of asthma, at lower levels of activity than children with normal lungs. To avoid this sensation the child reduces his or her level of activity, which leads to a greater degree of deconditioning, which in turn increases breathlessness at even lower levels of activity. The cycle continues until one is left with a population of inactive, unfit children who become teenagers and then adults. They may become too embarrassed to begin exercising again.

    Regular exercise is especially critical for children and teens with asthma.Many habits are well-formed by the time people reach their early teens. Children may learn to avoid outdoor play, sports, and other physical activities that produce symptoms. Untreated asthma and EIB can limit normal activities; this may result in lasting physical and psychological effects including poor self-image. Because of their decreased participation, for example, children with asthma may be considered lazy.

    Bibliography

    1. Sports Medicine for Primary Care, Willian E. Moats
    2. Goodman, The Pharmacological Basis of Therapeutics, Ninth Edition, Goodman & Gilman’s
    3. The Medical Clinics of North America, Vol 78, Num 2 , Gray I. Wadler.
    4. REVIEW ARTICLES: CURRENT CONCEPTS: EXERCISE-INDUCED ASTHMA New England Journal of Medicine,Volume 330 Number 19, May 12, 1994
    5.Diagnosis and Management of Exercise-Induced Asthma by Ned T. Rupp, MEd, MD THE PHYSICIAN AND SPORTS MEDICINE - VOL 24 - NO. 1 - JANUARY 96

    If you have suggestions or comments send an e-mail to Mário César Moreira de Araujo

    Back to Sports Medicine

    Back to SPECIALTIES

    Back to MEDSTUDENTS HOMEPAGE