CHRIS KOUTURES, MD

GENERAL PEDIATRICS

FELLOWSHIP TRAINED PRIMARY CARE SPORTS MEDICINE

 

EXERCISE-INDUCED BRONCHOSPASM

 

First recorded reference?

            Perhaps in Fable Literature- namely “The Three Little Pigs”

            “I’m going to huff, and puff, and blow your house down”

 

More recently…

            Incidence of EIB is on the rise- reasons are uncertain.

            Most quoted statistic- 12% of US Athletes in 1984 Olympics

            Had EIB, many of whom won medals.

 

What is exercise-induced bronchospasm?

                An obstructive disease of the middle-small caliber bronchi and bronchioles characterized by transient bronchospasm that follows 5-12 minutes of strenuous (>80% maximum heart rate for age) and peaks within 6-8 minutes after onset of symptoms. Significant impairment in athletic performance can occur due to coughing, wheezing, and chest tightness. Left untreated, the symptoms resolve gradually within 30-60 minutes.

 

What causes EIB?

EIB is more apt to occur following short periods of intense exercise- however, symptoms are known to follow exercise durations of up to 30 minutes. More vigorous, high-intensity exercise increases the respiratory rate from resting values of 12-16 breaths/ minute to 60-80 breaths/minute and can raise minute ventilation from 8 liters/minute to 140 liters/minute of inspired air. These increased demands reduce the ability of the nose and mouth to warm and humidify incoming air to body temperature and 100% saturation. Thus, the bronchi and lungs must give up warmth and water to contribute to this warming and humidification process.

 

While the exact pathophysiologic mechanisms are unknown, the following theories attempt to link these events with the clinical symptoms:

1) Respiratory heat loss leads to bronchial vascular dilation, resulting in airway obstruction

2) Respiratory water loss leads to increase pulmonary tissue osmolarity

3) Rapid breathing causes airway irritation with subsequent release of bronchospastic chemical mediators

4) Post-exercise rebound rewarming of airway tissues leads to bronchial swelling

 

                There are reports of a late-phase bronchospasm which may occur 4-12 hours after the initial activity and symptoms. These later symptoms are similar to those seen in asthmatics who are sensitive to allergens, and may represent the later-phase actions of inflammatory mediators. However, the exact role of inflammatory mediators, known to make common asthma worse, is unclear in EIB.  Epidiomiologic studies have not confirmed a high incidence of these late-phase reactions, but do be careful with athletes participating in “all-day” tournaments or in those who have “long” bus rides home after practice or competition.

 

BOTTOM LINE:

A)       THE SMALL AIRWAYS CONTRACT= BRONCHOSPASM

B)       THE SMALL AIRWAYS SWELL AND HAVE INCREASED MUCUS= OBSTRUCTION

EVEN MORE BASIC BOTTOM-LINE (GOOD FOR EXPLAINING TO PATIENTS AND FAMILIES)

                INSTEAD OF BREATHING THROUGH A TOILET PAPER ROLL, IMAGINE BREATING THROUGH A STRAW FILLED WITH PUDDING…..

 

 

500 S. Anaheim Hills Road, Suite 140              16300 Sand Canyon, Suite 100

Anaheim Hills, CA 92807                                              Irvine, CA 92620

(714) 974-2220                                                   (949) 754-1344

Which athletes may have EIB or be at risk for EIB (and who may not but says they do)?

 

            The athlete with a defined history of asthma may be a clear example of the purported 3-12% of pediatric and adolescent athletes who have EIB. However- there is much controversy regarding identifying and diagnosing individuals with this disorder.

           

A)       Many athletes are reluctant to report symptoms out of ignorance or fear of being labeled- thus in some circles, EIB is considered to be vastly under-reported.

B)       Many athletes have heard anecdotal reports of performance-enhancement with asthma medications, or may not “want to be left out”- thus in other arenas, EIB is considered to be over-reported.

 

A quick review of both the past medical history and observations made during exercise can help identify (or exclude) less obvious individuals.

 

The pre-participation history and exam can identify certain risk factors:

1)       90% of people with asthma experience symptoms during exercise and many consider exercise a major trigger for their disease. Recent reports indicate that the presence of EIB suggests insufficient baseline asthma control.

2)       35-40% of people with allergic rhinitis experience EIB.

3)       Family members with asthma or difficulty exercising due to respiratory limitations.

4)       Athletes with atopic skin disease are at high risk for EIB- especially during flares.

 

 

Once activity has begun, the following situations either during or after activity, may also suggest the presence of EIB.

1)       Athletes who have coughing, wheezing, dyspnea, or chest pain/tightness with exercise- especially out of proportion to level of exertion or in greater magnitude than that of their peers.

2)       Above symptoms that vary with season or outdoor (ambient) temperature- especially cold weather. Particular high-risk sports include ice skating and hockey.

3)       Athletes who complain of decreased or limited endurance, or    

        appear “out of shape” despite appropriate conditioning.

4)       Athletes who have multiple URI’s or require multiple antibiotic

        courses during the competitive season.   

5)       Be wary of swimming- once though to be a more “ideal” sport for

EIB, many swimmers now reporting symptoms.

Thought possibly due to chemicals used in modern pools?

 

 

How does one work-up an athlete with possible EIB?

 

1.       Believe the history

a.       Therapeutic trial of empiric medication

OR

2.       Further testing.

a.       Pulmonary Function Tests

b.      Exercise challenge

c.       Provocative challenge

 

 

 

 

 

Pulmonary Function Testing

1. Formal Spirometry

2. Hand-held Peak Flow Meter

Formal spirometry can measure FEV1 (forced expiratory volume in one second)- the most accurate measure of small airway caliber. However, this requires an office/clinical setting and cannot be used for repeated measures on the athletic field. Thus, the “poor-man’s” spirometer- the peak flow meter- is used to measure PEFR (peak expiratory flow rate). This hand-held device is easy to carry and can be used to help assess on-going pulmonary status.

 

Whether using FEV1 or PEFR, a baseline peak flow reading <80% of predicted (based on sex, race, and height) or actual personal best with >15% improvement after using a bronchodilator is consistent with the diagnosis of asthma.

 

Exercise Challenge Test

 

Combining PFT’s and exercise can make an objective diagnosis of EIB. Start with a baseling set of PFT’s, then perform a bout of exercise. This exercise bout can be as simple as informal “running the parking lot” at the clinic or actually performing a formal work-out. 

A formal work-out consists of 80% maximum heart rate (220-patient age in years) for 6-8 minutes.

The athlete then measures pulmonary function 5-10 minutes after activity.

For some athletes, having them measure peak flows before and after a practice/game session can act as an exercise challenge test.

A decrease in FEV1 of 10-15% or a decrease in the PEFR of 15-20% are both diagnostic of EIB.

 

Provocative Challenge Test

 

Operates on the same principles as the exercise challenge test, except that medication known to increase heart rate and respiratory rate is used in place of exercise. Rarely used.

           

 

How do I manage an athlete with exercise-induced asthma?

            There are several components to the management of an athlete with EIB, and like any good sport, this requires a team effort between the athlete, parent, coach, and medical personnel.

ANOTHER BOTTOM LINE: DON’T LET ASTHMA LIMIT PARTICIPATION!!!

OPTIMAL GOAL- PARTICIPATION IN SPORT FREE OF INTERFERENCE FROM EIB SYMPTOMS

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

BASIC TENETS

 

GET IN SHAPE: Increased physical conditioning reduces the requirements for medications and has been shown to decrease the incidence of asthma attacks. Aerobic exercise improves cardiac output and muscle tissue oxygenation at lower overall respiratory rates.

GET WARMED-UP: Experience has shown that in a second exercise challenge done within 1-2 hours after an initial exercise bout, less than half the original degree of obstruction occurs- this is due to the refractory period. There is no “universal” warm-up that will consistently induce the refractory state. The best recommendation is a brief, intense period of exercise of about 15 minutes duration, then a rest period of another 15-30 minutes before the desired activity may take advantage of this refractory period.

STAY WARM: Exercising in warm, humid environments or breathing through the nose rather than the mouth helps warm. filter, and humidify inspired air.

STAY SMART:  Be wary of conditions which make worsen symptoms- such as URI symptoms, cold weather, days with high allergen counts, and particular intense or emotional practices or games.  Air pollution and smog can also exacerbate EIB, thus some athletes may have to adjust activity on particularly bad days. Athletes with frequent EIB bouts should not exercise alone.

LEARN PEAK FLOWS:  Particularly useful in athletes who has asthma attacks outside of exercise, can also be used during times of URI’s to determine severity of illness and possible modifications to exercise.

GREEN ZONE (80-100% PEAK FLOW)

NO CHANGE IN ACTIVITY OR MEDICATION

YELLOW ZONE (60-80% PEAK FLOW)

REDUCE EXERCISE OR INCREASE MEDICATION

RED ZONE (<60% PEAK FLOW)

NO EXERCISE, CONSULT MEDICAL PROFESSIONAL

 

 

MEDICAL MANAGEMENT

 

FIRST-LINE: INHALED, SHORT-ACTING BETA-AGONISTS

            (ALBUTEROL, PROVENTIL, PIRBUTEROL, METAPROTERENOL)

 

When used properly, have been shown to reduce EIB symptoms in 80% of athletes for up to 4-6 hours.

            *Rapid onset of action (usually within 5 minutes) with maximal bronchodilation in 15 minutes

            *To take advantage of refractory period, dose as follows:

                        Take 2 puffs

                        15 minute warm-up period

                        15-30 minutes break (stretching, team meeting)

                        Intense, formal part of activity

            *Thus, athletes with EIB might have to incorporate their own “early warm-up”

            *On-demand 2 puff dosing can be used during activity for symptoms flares

            *Should bring this inhaler to all practices and games- let others know of its location

            *More frequent use (more than every 2-4 hours or more than 3 times/day) requires

             further evaluation.

 

 

 

 

 

 

SECOND-LINE: TWO OPTIONS

 

A.      MAST-CELL STABILIZERS

(Intal, Cromolyn, Nedocromil)

Best used in athletes who have little/no baseline symptoms, a single exercise session during the day, and no trouble outside of sport.

Recent research indicates a benefit to combining short-acting beta-agonists with inhaled mast-cell stabilizers. This medication is usually indicated in scheduled daily doses for control of chronic asthma, but two or four puffs in conjunction with the beta-agonist right before exercise can reduces bronchial narrowing in cases of extreme minute ventilation.

 

B.      LEUKOTRIENE ANTAGONISTS

(Singulair, Accolade)

Newer products indicated in athletes with baseline asthma, symptoms outside of activity, and in those athletes with “spontaneous play” or multiple exercise sessions in a given day.

Used on a prophylactic basis once or twice a day- doesn’t obviate need for short-acting beta agonists- confers greater symptom control and time missed from activities. Personal experience: benefit seen within 1-2 weeks, results can be fairly dramatic and no side effects noted.

 

            THIRD-LINE: MULTIPLE OPTIONS

1)       Long-acting beta-agonists (Salmuterol): 30-60 minute onset of action limits use in cases of acute need. Duration of action is 12 hours, thus can be beneficial to those who plan to exercise for prolonged periods or for several hours after treatment. Also has been shown to benefit individuals who are “dependent” on short-acting beta-agonists- can reduce use of these agents.

2)       Inhaled/oral corticosteroids (numerous): Inhaled agents used for daily control of inflammation- more apt to be recommended for athletes who have baseline symptoms at rest. Oral agents used for burst 3-5 day dosing in times of acute illness.

Side note: when recommending corticosteroids- explain to the athlete and family the distinction between them and anabolic steroids. Many athletes are conditioned that steroids are illegal and “bad” for them…

            

IMPORTANT INFORMATION FOR NCAA AND USOC/IOC CALIBER ATHLETES

BETA AGONISTS: some studies suggest that certain drugs in this class may act as anabolic agents for skeletal muscle enhancement. These effects are limited to a few drugs- all banned- the most notable is clenbuterol. As for albuterol and other agents, the limits are as follows:

                NCAA: Permits most beta-agonists only in inhaled dosage formulations which produce minimal blood concentrations.

                USOC/IOC: Permits maximum of two beta-agonists per athlete upon medical notification prior to competition and only in inhaled formulations.

CORTICOSTEROIDS

                NCAA: No restrictions

                USOC/IOC: oral corticosteroids are banned, while inhaled corticosteroids are permitted with prior medical notification.

OVER-THE-COUNTER: There are several OTC multi-ingredient anti-asthma medications, some of which are banned (Primatene mist, for example). Closely check the status of all meds before use.

RULE-OF-THUMB: Document medical indications and doses for all medications- especially around elite competitions that may require drug testing.