長距離或劇烈運動後的呼吸疼痛或呼吸困難、不能深呼吸等其實屬於正常現象，雖然原因還不是很明確，但是由於通常發生於天氣較冷和乾燥時，所以大部分研究人員都認為是和呼吸道的刺激有關。
我認為pengyou這個現象和(EIA) 运动性哮喘的發生有一定的關聯性，但是程度還沒有嚴重到可以診斷為EIA。
EIA的主要症狀是(運動後):
1. 咳嗽-干咳为主，容易受刺激而引发，早上和深夜較嚴重
2. 喘息
3. 呼吸短促
4. 胸部緊張感
我下面转一些文章你们看吧。
Exercise-Induced Asthma
Article Last Updated: Nov 1, 2007
AUTHOR AND EDITOR INFORMATION
Section 1 of 10  
Author: Anthony J Saglimbeni, MD, Staff Physician, Family Practice Residency, Medical Director, Center for Sports Medicine, O'Connor Hospital; Private Practice
Editors: Joseph P Garry, MD, Director of Sports Medicine
and Sports Medicine Fellowship, Associate Professor of Family Medicine
and Exercise & Sport Science, Department of Family Medicine, East Carolina University Brody School of Medicine; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine; Russell D White, MD,
Professor of Medicine, Department of Community and Family Medicine,
University of Missouri-Kansas City School of Medicine, Truman Medical
Center Lakewood; Jon B Whitehurst, MD, Clinical Instructor of
Surgery, University of Illinois College of Medicine; Partner and
Executive Board Member, Rockford Orthopedic Associates; Orthopedic
Chairman, Rockford Memorial Hospital; Craig C Young, MD,
Professor, Departments of Orthopedic Surgery and Community and Family
Medicine, Medical Director of Sports Medicine, Sports Medicine
Fellowship Director, Medical College of Wisconsin
Author and Editor Disclosure
Synonyms and related keywords:
EIA, exertional asthma, exercise-induced bronchospasm, EIB,
exercise-induced urticaria, allergic rhinitis, bronchoconstriction,
exercise-related respiratory symptoms, wheezing, chest tightness,
shortness of breath, dyspnea, difficulty breathing, aerobic exercise,
environmental factors, allergic asthma, asthmogenic agents
Background
Exercise-induced asthma (EIA) is a condition of respiratory
difficulty that is triggered by aerobic exercise and lasts several
minutes. Symptoms of EIA may resemble those of allergic asthma, or they
may be much more vague and go unrecognized, resulting in probable
underreporting of the disease. (See also the Medscape Asthma Resource Center and the eMedicine article Asthma.) Exercise-induced
urticaria, or anaphylaxis, is often presumed to be related to EIA, even
though this condition is extremely rare and unrelated. EIA is related
to histamine release.1, 2, 3
Only 500-1000 cases of exercise-induced urticaria have been reported in
the literature. In this condition, there is an early stage of
exercise-related fatigue and itchiness, followed by early onset of
urticaria and angioedema, which is initially mild.4
If progression occurs, there is choking, stridor, nausea, vomiting, and
even hypotension. A late stage that is marked by headache may also
occur. As implied by the alternative name of anaphylaxis, EIA can be
life threatening; however, this can be prevented by exercise
modification or avoidance of certain conditions (see Sport-Specific Biomechanics, below).
(See also the eMedicine articles Exercise-Induced Anaphylaxis [in the Pediatrics section], Urticaria [in the Allergy and Immunology section], and Angioedema [in the Emergency Medicine section].)
Frequency
United States
EIA affects 12-15% of the population. Ninety percent of asthmatic
individuals and 35-45% of people with allergic rhinitis experience
EIA, but even when those with rhinitis and allergic asthma are
excluded, a 3-10% incidence of EIA is seen in the general population.3 EIA seems to be more prevalent in some winter or cold-weather sports.5
Some studies have demonstrated rates as high as 35% or even 50% in
competitive-caliber figure skaters, ice hockey players, and
cross-country skiers.6, 7
Functional Anatomy
The problem in EIA occurs distal to the glottis, in the lower
airway. Bronchoconstriction is involved that is distinguishable from
laryngospasm, which can occur in other exercise-related conditions. One
such example is the condition known as vocal cord dysfunction in
which there is paradoxical narrowing of the vocal cords during
inspiration, resulting in stridor that is often misconstrued as audible
wheezing.8, 9 Normally, the vocal cords open with inspiration. (See also the eMedicine article Vocal Cord Dysfunction.)
Sport-Specific Biomechanics
EIA usually affects individuals who participate in sports that
include an aerobic component. The condition can be seen in any sport,
but EIA is much less common in predominantly anaerobic activities. This
is likely due to the role of consistent and repetitive air movement
through the airways (seen in aerobic sports), which affect airway
humidity and temperature. EIA triggers an unknown biochemical and
neurochemical pathway, resulting in the bronchospasm, which manifests
as the symptoms of the disease. Although the exact mechanism of
EIA is unknown, there are 2 predominant theories as to how the symptom
complex is triggered. One is the airway humidity theory, which suggests
that air movement through the airway results in relative drying of the
airway. This, in turn, is believed to trigger a cascade of events that
results in airway edema secondary to hyperemia and increased perfusion
in an attempt to combat the drying. The result is bronchospasm. The
other theory is based on airway cooling and assumes that the air
movement in the bronchial tree results in a decreased temperature of
the bronchi, which may also trigger a hyperemic response in an effort
to heat the airway. Again, the result is a spasm in the bronchi.
Many
authors think that there may be a combination of the above 2 theories
that takes place, but the biochemical or physical pathways that mediate
these responses are unclear. Evidence may even exist to support the
idea that the resulting cascades are not the inflammatory pathways to
which we attribute allergic asthma. Likewise, certain sports and
their environments predispose individuals with asthma to experience
EIA. Sports played in cold and dry environments usually result in more
symptom manifestation for athletes with this condition. On the other
hand, when the environment is warm and humid, the incidence and
severity of EIA decrease.
History
Patients usually present complaining of exercise-related respiratory
symptoms. This complaint is much more common among children and younger
athletes but can be seen at any age. - Symptoms during or following exercise include the following1, 3:
- Chest tightness or pain
- Cough
- Shortness of breath
- Wheezing
- Underperformance or poor performance on the field of play
- Fatigue
- Prolonged recovery time
- Gastrointestinal (GI) discomfort
- Symptom denial may be seen due to the following:
- Peer pressure
- Embarrassment
- Fear of losing position on the team
- Misinterpretation as postexercise fatigue
- Contributing factors consist of the following:
- Cool temperatures
- Low-humidity environment
- Poor air quality
- High pollen counts
- Coincident respiratory infection
- Poor physical conditioning
- Exercise factors can include the following:
- Aerobic exercise appears to be much more problematic than anaerobic exercise.
- Duration of aerobic activity greater than 8-10 minutes provokes EIA.
- High-intensity aerobic exercise also provokes EIA.
- Time interval between sessions of aerobic exercise
- Refractory phase
- Starts less than 1 hour after initial aerobic exercise
- Lasts up to 3 hours
- The refractory phase results in as little as one half the degree of bronchospasm as in the first episode.
- Occurrence is unpredictable and intermittent
- The warm-up period can be used in an attempt to ensure that competition occurs during this refractory phase.
- The
mechanism is unknown but is believed to involve the following
possibilities: depletion of mast cell mediators, release of endogenous
catecholamines, and release of endogenous protective prostaglandins.
- Late-phase response
- This
phase occurs 3-9 hours after the initial exercise challenge, and unlike
the refractory phase, the late phase manifests as an increase in
symptoms, with cough, wheezing, or shortness of breath.
- This
response is much more common in children and is more likely to occur if
severe early exercise-induced bronchospasm (EIB) is present.
- This late-phase response is usually less severe than the early response.
Physical
The patient's physical examination is often unremarkable in the
clinical setting; a higher yield is obtained on the field or after an
exercise challenge.10
Exercise challenge, for the purpose of the physical examination, may be
informal. For example, the clinician may have the athlete come to the
office wearing athletic clothing and run on a treadmill or around the
parking lot for 10 minutes, which is then followed by another pulmonary
examination. - The physical examination should include the following areas:
- Skin (note any signs of atopic disease)
- Head, ears, eyes, nose, and throat (note any evidence of acute infection, chronic infection, allergic/atopic disease)
- Pharynx (note any mucus, cobblestoning, erythema)
- Nose (note the presence of enlarged turbinates, erythema, congestion)
- Sinuses (note the presence of tenderness)
- Lungs (note the presence of rales, rhonchi, wheezes, a prolonged expiratory phase)
- Heart (note the presence of murmurs, an irregular rhythm)
Causes
The causes of EIA can be divided into the categories of medical,
environmental, and drug related. Eliminating some causes can
diminish—but may not eliminate—the athlete's symptoms. EIA may also
exist without the presence of any of these causes. - Medical
- Poorly controlled asthma results in increased patient symptoms with exercise.
- Maximizing control of the patient's baseline asthma, when present, is critical in the treatment of EIA.1
- Poorly controlled allergic rhinitis also results in increased patient symptoms with exercise.
- Secretions resulting from hay fever can aggravate both allergic asthma and EIA.
- Viral, bacterial, and other forms of upper respiratory infections also aggravate the symptoms of EIA.
- Controlling the secretions of these illnesses, as with allergic rhinitis, can make the EIA symptoms much more tolerable.
- Environmental
- Excess of pollens or other allergens in the air can exacerbate the allergic and exercise-induced forms of asthma.
- Pollutants in the air are irritants to the airways and can lower the threshold for symptomatic bronchospasm.
- The
chemicals used in certain sports for environmental maintenance can
predispose individuals to wheezing and worsen EIA symptoms. These
chemicals include the following:
- Chlorination in pools
- Insecticides and pesticides used to maintain playing fields
- Fertilizers and herbicides used to maintain playing fields
- Paints and other decorative substances to enhance the appearance of playing fields
- Drugs – Asthmogenic agents include the following:
- Beta-blockers (β-blockers)
- Aspirin
- Nonsteroidal anti-inflammatory drugs (NSAIDs)
- Diuretics
- Zanamivir
Anxiety
Hyperventilation Syndrome
Vocal Cord Dysfunction
Other Problems to Be Considered
Deconditioning syndrome
Seasonal asthma (See also the eMedicine article Allergic and Environmental Asthma.)
Upper airway obstruction (See also the eMedicine article Stridor.)
Lab Studies
- In general, EIA is diagnosed clinically and may not need
any further laboratory studies, imaging, or other tests and
procedures. Laboratory evaluation is reserved for equivocal cases, for
treatment failures, and to narrow the differential diagnosis when it
seems reasonable. Therefore, consider testing to evaluate cardiac
conditions, vocal cord and upper airway obstructive conditions,
allergic conditions, and psychiatric conditions.
- A complete
blood cell count and differential ("CBC with diff") can help in
the assessment of the likelihood of infection by analysis of the
patient's white blood cells and by evaluation of the eosinophil counts
(for allergy).
- An erythrocyte sedimentation rate (ESR) result may help in the evaluation of inflammatory and infectious conditions.
- Assessing the immunoglobulin E (IgE) count helps in determining the likelihood of allergic disease.
- Skin
allergen testing or a radioallergosorbent test (RAST) can be used to
help identify specific allergens to promote patient avoidance or
immunotherapy, if indicated. Either method has been used extensively in
atopic workups. In young children, RAST testing may be preferable owing
to the relative ease of administration, but this is a less specific
test, and therefore, skin testing may be preferred in general.
(See also the Medscape articles Specific IgE Testing: Objective Evidence of Sensitization Aids Diagnosis and Treatment Decisions, Allergy Testing in Children, and Skin Testing in Asthmatics Treated With Omalizumab.) - Thyrotropin
levels can be used to help evaluate the potential of patient thyroid
dysfunction in the likelihood that anxiety is mimicking the symptoms of
asthma. (See also the eMedicine article Anxiety.)
- If
the diagnosis is uncertain, performing a nasal swab for the presence of
eosinophils is helpful in identifying the role of allergic rhinitis.
(See also the eMedicine article Rhinitis, Allergic.)
- Sputum
analysis and culture can be used to help identify the presence of
infection and treatment options for strains of resistant organisms.
Imaging Studies
- Imaging studies are often not indicated in the
evaluation of routine EIA, but they may be useful for evaluating other
possibilities in the differential diagnosis.
- Chest radiograph
- To evaluate for signs of chronic lung disease (eg, hyperexpansion, scarring, fibrosis, hilar adenopathy)
- To
evaluate for congestive heart failure and/or valvular heart disease
(eg, chamber enlargement, pulmonary edema, vascular or valvular
calcification) (See also the eMedicine article Congestive Heart Failure and Pulmonary Edema.)
- To evaluate for a foreign body
- Lateral
neck radiographs/soft-tissue penetration to evaluate the upper airway
for a foreign body or obstruction (See also the eMedicine articles Foreign Bodies of the Airway [in the Otolaryngology and Facial Plastic Surgery section] and Airway Foreign Body [in the Radiology section].)
- Echocardiography to evaluate for cardiac valvular abnormality or global contractile function
Other Tests
- Echocardiography can also be used to evaluate
dysrhythmia, cardiomegaly, or other heart disease that may manifest
during exercise.
Procedures
- Various challenge tests exist that can be used to
formalize the diagnosis of EIA. A formal diagnosis is often not
critical, clinically, but in recent years, the US Olympic Committee has
required a positive challenge test to be documented for an athlete to
qualify for the use of controlled substances that aid in ameliorating
the symptoms of EIA. This requirement has resulted in new studies that
have been used to validate some of these assessment tools, whether they
are field challenges, treadmill testing, or new techniques such as
eucapnic voluntary hyperventilation (EVH).7, 10, 11
- Treadmill exercise challenges with preexercise and postexercise pulmonary functions
- This
type of testing formalizes an aerobic challenge and provides an
objective measure of the degree of bronchospasm that results from the
exercise. The results can help the physician to clarify the diagnosis
and to enforce the treatment; the results can also be used to evaluate
success of the treatment.
- Before the exercise challenge, the
patient's baseline pulmonary function levels should be obtained
(preferably forced expiratory volume in 1 second [FEV1], forced vital capacity [FVC], or FEV1/FVC,
or, less ideally, peak expiratory flow rate [PEFR]). The exercise
challenge involves exercising the athlete on a treadmill until his or
her heart rate reaches 70-85% of the maximum predicted heart rate. This
is maintained for 6-10 minutes, at which time the exercise is stopped.
Pulmonary function levels are measured every 2-10 minutes for 15-30
minutes and then compared with the baseline measurements.
- Any
drop from the baseline that is greater than or equal to 10%, on any
postexercise measurement, indicates EIA. Severity of disease can be
classified as follows:
- Mild – Decrease of 10-20% from baseline
- Moderate – Decrease of 20-40% from baseline
- Severe – Decrease of greater than 40% from baseline
- An
informal exercise challenge can be substituted for the above procedure,
but without monitoring the heart rate, the level of work is not
reliable.
- Laryngoscopy can be performed to evaluate for foreign body or other obstruction in the upper airway.
- Postexercise
laryngoscopy can be used to evaluate for vocal cord dysfunction, a
condition often mistaken for EIA. Vocal cord dysfunction manifests as
stridor with exercise due to paradoxical contraction of the vocal cords
with inspiration; this condition can be evaluated via laryngoscopy
after an exercise challenge.
- Pulmonary function testing can be
used to evaluate baseline pulmonary function or allergic asthma and to
categorize pulmonary function as obstructive or restrictive disease.
- Bronchoprovocation
testing, as used with general asthma, methacholine, histamine, or cold
air challenges, can be used to assess asthma. However, if the results
are positive, they are indicative of asthma in general, not
specifically EIA.
- EVH is a new technique believed to be more sensitive and more accurate for diagnosing EIA.7, 11
Furthermore, EVH can be applied in a laboratory setting and altered to
mimic the environmental conditions of the sport in question.
Acute Phase
Medical Issues/Complications
Although rare, as with any asthma attack, progression of EIA can
result in status asthmaticus and even death. Treatment for this
condition should be provided immediately and the situation taken
seriously. (See also the eMedicine articles Status Asthmaticus [in the Pediatrics section] and Status Asthmaticus [in the Pulmonology section].)
Consultations
On the playing field, consultation is rarely available and is not
needed in the acute EIA attack; however, access to the emergency
medical system should be readily available.
Other Treatment
Treatment of the athlete who is experiencing an acute attack of EIA
is the same as in any asthma attack situation and includes the
following: - Immediately remove the patient from competition or play.
- Provide immediate administration of a rapid onset, short-acting β2-agonist
(eg, albuterol); this has the highest therapeutic yield. The usual dose
is 2 puffs of albuterol via a metered dose inhaler (MDI).
- If
the patient's response is not satisfactory, transportation to an
emergency facility should be initiated because the EIA attack may
escalate.
- If available, the use of a spacer device can help to
transport the medication to the area of greatest need, especially when
an athlete is distracted in the midst of competition or anxious from
dyspnea and unable to concentrate.
- If the initial
treatment fails or is unavailable, immediate transfer of the patient to
an acute care facility should occur. Subcutaneous epinephrine can be
administered in such life-threatening situations.
Recovery Phase
Medical Issues/Complications
If the initial response to treatment was adequate, patient
observation and monitoring need to continue for several hours in case
of a relapse.
Consultations
If patient relapse is immediate, transportation to an emergency facility should be initiated.
Other Treatment (injection, manipulation, etc)
If mild, residual symptoms persist in the patient after relief of
the acute symptoms, a repeat administration of albuterol is advisable;
the recommended dosing interval is 4 hours.
Maintenance Phase
Medical Issues/Complications
Long-term treatment of EIA is prevention of the condition (see Medication).1
Other Treatment
Nonpharmacologic measures can also be taken in the treatment of EIA.
- Sports
selection – It can be helpful to guide an athlete toward the
performance of sports in environments that are less likely to cause
bronchospasm. If the athlete has a choice, he or she can choose a time
or place to exercise where the air is warmer and the humidity is
higher. Likewise, a flexible athlete can change sports to be more
active in these sorts of environments (eg, changing from running to
swimming automatically increases the humidity of the environment). As
indicated earlier, focusing on sports with less prolonged aerobic
demands (eg, sprinting, weight lifting, baseball, football) is better
tolerated by affected athletes.
- Breathing and warm-up techniques:
- Altering
breathing techniques – A change from predominant mouth breathing to
nasal breathing can result in less bronchospasm with the performance of
an activity because the inhaled air is both warmed and humidified.
- The
coordination and timing of competition with medication use can also
maximize exercise performance with regard to bronchospasm. To minimize
the likelihood of bronchospasms, the athlete can time the warm-up so
that the competition coincides with a refractory phase. This is most
likely to occur by initiating a 15-30 minute warm-up followed by a
15-minute rest period, at which time the medication is administered.
This entire period should be timed to result in commencement of the
competition 15-30 minutes after medication administration.
The optimal treatment for EIA
is to prevent the onset of symptoms. After controlling the patient's
underlying and contributing factors (eg, respiratory infection,
allergy, allergic asthma), a combination of drugs can be used to
prevent EIA.1 The basis of treatment is with preexercise short-acting β2-agonist administration.1 A role also exists for long-acting β2-agonists and mast cell stabilizers. Antileukotriene drugs have been shown to be effective as well.12, 13
Traditional asthma medications (eg, corticosteroids, theophylline) have
less of a role in the treatment of pure EIA. There is ongoing
investigation regarding other agents (eg, heparin, calcium-channel
blockers, diuretics).
Drug Category: Beta2-agonists
These agents are used for prophylactic bronchodilation to prevent
the onset of symptoms with exercise and have been shown to have a 90%
efficacy.
| Drug Name | Albuterol (Proventil, Ventolin) |
|---|
| Description | DOC and first-line agent. β2-agonist for bronchospasm that is refractory to epinephrine. Relaxes bronchial smooth muscle by action on β2-receptors with little effect on cardiac muscle contractility. |
|---|
| Adult Dose | 2 puffs via metered dose inhaler 15-30 min preexercise |
|---|
| Pediatric Dose | 1-2 puffs via metered dose inhaler 15-30 min preexercise |
|---|
| Contraindications | Documented hypersensitivity; tachyarrhythmias; hypokalemia |
|---|
| Interactions | Caution with other sympathomimetics, MAOIs, tricyclic antidepressants, other agents that decrease potassium |
|---|
| Pregnancy | C
- Fetal risk revealed in studies in animals but not established or not
studied in humans; may use if benefits outweigh risk to fetus
|
|---|
| Precautions | May cause jitteriness and tachycardia; caution with hypokalemia from repetitive and frequent use |
|---|
| Drug Name | Salmeterol (Serevent) |
|---|
| Description | By
relaxing the smooth muscles of the bronchioles in conditions that are
associated with bronchitis, emphysema, asthma, or bronchiectasis,
salmeterol can relieve bronchospasms. Effect may also facilitate
expectoration.
Adverse effects are more likely to occur when
this agent is administered at high or more frequent doses than
recommended; the incidence of side effects is then higher. |
|---|
| Adult Dose | 2 puffs via metered dose inhaler 30-45 min preexercise or bid |
|---|
| Pediatric Dose | 1-2 puffs via metered dose inhaler 30-45 min preexercise or bid |
|---|
| Contraindications | Documented hypersensitivity; tachyarrhythmias; hypokalemia |
|---|
| Interactions | Caution with other sympathomimetics, MAOIs, tricyclic antidepressants |
|---|
| Pregnancy | C
- Fetal risk revealed in studies in animals but not established or not
studied in humans; may use if benefits outweigh risk to fetus
|
|---|
| Precautions | Educate patient that this agent is not to be used as a rescue treatment for acute bronchospasm; long-acting β2-agonists may cause more tachyphylaxis than short-acting agents. |
|---|
Drug Category: Mast cell stabilizers
These agents are 70-80% effective in preventing bronchospasm during
exercise. An additive effect is noted when used in combination with
albuterol.
| Drug Name | Cromolyn sodium (Intal, Nasalcrom) |
|---|
| Description | First- or second-line agent in the prevention of EIA. |
|---|
| Adult Dose | 2 puffs via metered dose inhaler 30-45 min preexercise |
|---|
| Pediatric Dose | 1-2 puffs via metered dose inhaler 30-45 min preexercise |
|---|
| Contraindications | Documented hypersensitivity |
|---|
| Interactions | None reported |
|---|
| Pregnancy | B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals
|
|---|
| Precautions | Educate
patient that this agent is not to be used as a rescue treatment for
acute bronchospasm; avoid use with isoproterenol during pregnancy. |
|---|
Drug Category: Inhaled corticosteroids
These agents provide no bronchodilatory effect but are useful in controlling the underlying inflammation of allergic asthma.
| Drug Name | Flunisolide (AeroBid Oral Aerosol Inhaler, Nasalide Nasal Aerosol) |
|---|
| Description | Decreases
inflammation by suppressing migration of polymorphonuclear leukocytes
and reversing capillary permeability. Does not depress the
hypothalamus. Considered a third-line agent. |
|---|
| Adult Dose | 2-4 inhalations qd/qid; varies with preparation |
|---|
| Pediatric Dose | <6 years: Some preparations are contraindicated
>6 years: 1-4 inhalations qd/qid; varies with preparations |
|---|
| Contraindications | Documented hypersensitivity |
|---|
| Interactions | None reported |
|---|
| Pregnancy | C
- Fetal risk revealed in studies in animals but not established or not
studied in humans; may use if benefits outweigh risk to fetus
|
|---|
| Precautions | Educate patient that this agent is not to be used as a rescue treatment for acute bronchospasm. |
|---|
| Drug Name | Triamcinolone acetonide (Azmacort) |
|---|
| Description | Decreases
inflammation by suppressing migration of polymorphonuclear leukocytes
and reversing capillary permeability. Considered a third-line agent. |
|---|
| Adult Dose | 2-4 inhalations qd/qid; varies with preparation |
|---|
| Pediatric Dose | <6 years: Some preparations are contraindicated
>6 years: 1-4 inhalations qd/bid/tid/qid; varies with preparations |
|---|
| Contraindications | Documented hypersensitivity |
|---|
| Interactions | None reported |
|---|
| Pregnancy | C
- Fetal risk revealed in studies in animals but not established or not
studied in humans; may use if benefits outweigh risk to fetus
|
|---|
| Precautions | Educate patient that this agent is not to be used as a rescue treatment for acute bronchospasm; do not exceed recommended doses. |
|---|
| Drug Name | Beclomethasone dipropionate (Beclovent, Beconase, Vancenase, Vanceril) |
|---|
| Description | Inhibits
bronchoconstriction mechanisms; produces direct smooth muscle
relaxation; may decrease number and activity of inflammatory cells, in
turn decreasing airway hyperresponsiveness. Considered a third-line
agent. |
|---|
| Adult Dose | 2-4 inhalations qd/qid; varies with preparation |
|---|
| Pediatric Dose | <6 years: Some preparations are contraindicated
>6 years: 1-4 inhalations qd/qid; varies with preparations |
|---|
| Contraindications | Documented hypersensitivity, bronchospasm, status asthmaticus, other types of acute episodes of asthma |
|---|
| Interactions | Coadministration with ketoconazole may increase plasma levels but do not appear to be clinically significant |
|---|
| Pregnancy | C
- Fetal risk revealed in studies in animals but not established or not
studied in humans; may use if benefits outweigh risk to fetus
|
|---|
| Precautions | Educate patient that this agent is not to be used as a rescue treatment for acute bronchospasm. |
|---|
Drug Category: Xanthine derivatives
Xanthine derivatives have been used in allergic asthma for their
bronchodilatory and anti-inflammatory properties; however, these agents
have multiple side effects. Therefore, monitoring for nontoxic levels
is necessary.
| Drug Name | Theophylline (Aminophylline, Theo-24, Theolair) |
|---|
| Description | Potentiates
exogenous catecholamines, stimulates endogenous catecholamine release
and diaphragmatic muscular relaxation, which in turn stimulates
bronchodilation.
For bronchodilation, near-toxic (>20 mg/dL) levels are usually required. |
|---|
| Adult Dose | 5.6 mg/kg loading dose (based on aminophylline) IV over 20 min, followed by maintenance infusion of 0.1-1.1 mg/kg/h |
|---|
| Pediatric Dose | 6
weeks to 6 months: 0.5 mg/kg/h loading dose IV in first 12 h (based on
aminophylline), followed thereafter by maintenance infusion of 12
mg/kg/d; may administer continuous infusion by dividing total daily
dose by 24 h
6 months to 1 year of age: 0.6-0.7 mg/kg/h, loading
dose IV in first 12 h, followed by maintenance infusion of 15 mg/kg/d;
may administer as continuous infusion, as above
>1 year: Administer as in adults |
|---|
| Contraindications | Documented
hypersensitivity; patients with uncontrolled arrhythmias, peptic
ulcers, hyperthyroidism, and uncontrolled seizure disorders |
|---|
| Interactions | Aminoglutethimide,
barbiturates, carbamazepine, ketoconazole, loop diuretics, charcoal,
hydantoins, phenobarbital, phenytoin, rifampin, isoniazid, and
sympathomimetics may decrease effects of theophylline; theophylline
effects may increase with allopurinol, β-blockers,
ciprofloxacin, corticosteroids, disulfiram, quinolones, thyroid
hormones, ephedrine, carbamazepine, cimetidine, erythromycin,
macrolides, propranolol, and interferon. |
|---|
| Pregnancy | C
- Fetal risk revealed in studies in animals but not established or not
studied in humans; may use if benefits outweigh risk to fetus
|
|---|
| Precautions | Caution
in patients with peptic ulcer disease, hypertension, tachyarrhythmias,
hyperthyroidism, and compromised cardiac function; do not inject IV
solution >25 mg/min; patients with pulmonary edema or liver
dysfunction are at greater risk of toxicity because of reduced drug
clearance. |
|---|
Drug Category: Leukotriene receptor antagonists
Leukotriene receptor antagonists can be used as adjuncts in cases
of incompletely controlled EIA with the use of other agents; however,
leukotriene receptor antagonists should be reserved for more frequent
and persistent cases of EIA rather than for intermittent cases.
Leukotriene receptor antagonists should not to be used alone for the
treatment of EIA.
| Drug Name | Zafirlukast (Accolate) |
|---|
| Description | Inhibits
effects by the leukotriene receptor, which has been associated with
asthma, including airway edema, smooth muscle contraction, and cellular
activity associated with the symptoms. Third-line agent and used as
adjunct only. |
|---|
| Adult Dose | 20 mg PO bid |
|---|
| Pediatric Dose | 10 mg PO bid |
|---|
| Contraindications | Documented hypersensitivity |
|---|
| Interactions | Erythromycin
and theophylline decrease serum levels; aspirin increases levels of
zafirlukast; zafirlukast increases toxicity of warfarin. |
|---|
| Pregnancy | B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals
|
|---|
| Precautions | Educate
patient that this agent is not to be used as a rescue treatment for
acute bronchospasm; may cause liver inflammation; not for use as
monotherapy in the management of EIB |
|---|
| Drug Name | Montelukast (Singulair) |
|---|
| Description | Inhibits
the leukotriene receptor effects associated with asthma, including
airway edema, smooth muscle contraction, and cellular activity
associated with the symptoms. Third-line agent and used as an adjunct
only. European studies have suggested an improvement in gas exchange
versus β2-agonist medication. |
|---|
| Adult Dose | 10 mg PO at least 2 h before exercise; do not repeat dose within 24 h |
|---|
| Pediatric Dose | <15 years: Not established; some pediatric subspecialists recommend 5 mg PO qd
>15 years: Administer as in adults |
|---|
| Contraindications | Documented hypersensitivity |
|---|
| Interactions | Phenobarbital and rifampin reduce effects. |
|---|
| Pregnancy | B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals
|
|---|
| Precautions | Not
indicated to reverse acute asthma attacks; not for use as monotherapy
in the management of EIB; use appropriate short-acting, inhaled β2-agonist
for exacerbations; if already taking montelukast daily (eg, chronic
asthma, allergic rhinitis), do not take an additional dose to prevent
EIB; administration for chronic asthma has not been established to
prevent acute EIB; chewable tab contains phenylalanine: caution in
patients with phenylketonuria |
|---|
| Drug Name | Zileuton (Zyflo) |
|---|
| Description | Inhibits
leukotriene formation, which in turn decreases neutrophil and
eosinophil migration, neutrophil and monocyte aggregation, leukocyte
adhesion, capillary permeability, and smooth muscle contractions.
Third-line therapy and used as an adjunct only. |
|---|
| Adult Dose | 600 mg PO qid |
|---|
| Pediatric Dose | Not established |
|---|
| Contraindications | Documented
hypersensitivity; patients with active liver disease or transaminase
elevation greater than or equal to 3 times the upper limit of the
normal value |
|---|
| Interactions | Monitor drugs that are metabolized by cytochrome p3A4; potentiates theophylline, warfarin, and propranolol |
|---|
| Pregnancy | C
- Fetal risk revealed in studies in animals but not established or not
studied in humans; may use if benefits outweigh risk to fetus
|
|---|
| Precautions | Educate patient that this agent is not to be used as a rescue treatment for acute bronchospasm; monitor liver enzymes. |
|---|
Drug Category: Adrenergic agonists
Adrenergic agonists are used in the emergency treatment of
life-threatening situations, when β-agonists are unavailable or
treatment with β-agonists has failed.
| Drug Name | Epinephrine (Adrenalin, Bronitin, EpiPen, Primatene Mist) |
|---|
| Description | Has α-agonist
effects that include increased peripheral vascular resistance, reversed
peripheral vasodilatation, systemic hypotension, and vascular
permeability. β-agonist
effects of epinephrine include bronchodilation, chronotropic cardiac
activity, and positive inotropic effects. Indicated in the emergency
treatment of bronchospasm. |
|---|
| Adult Dose | 0.2-1 mg SC q4h prn |
|---|
| Pediatric Dose | 0.01 mg/kg SC q4h prn; not to exceed 0.5 mg |
|---|
| Contraindications | Documented
hypersensitivity; cardiac arrhythmias; angle-closure glaucoma; local
anesthesia in areas such as fingers or toes because vasoconstriction
may produce sloughing of tissue; during labor (may delay second stage
of labor) |
|---|
| Interactions | May potentiate the pressor effects of tricyclic antidepressants, furazolidone, antihistamines, levothyroxine, β-blockers, and guanethidine; epinephrine may be antagonized by nitrites and α-blockers; should avoid digitalis and other arrhythmia-producing agents |
|---|
| Pregnancy | C
- Fetal risk revealed in studies in animals but not established or not
studied in humans; may use if benefits outweigh risk to fetus
|
|---|
| Precautions | Caution
in elderly patients and in patients with prostatic hypertrophy,
hypertension, cardiovascular disease, diabetes mellitus,
hyperthyroidism, and cerebrovascular insufficiency; rapid IV infusions
may cause death from cerebrovascular hemorrhage or cardiac arrhythmias |
|---|
Return to Play
The severity of an EIA attack varies greatly. Although cases of
respiratory arrest and even death have been reported, the usual
scenario is of a mild respiratory difficulty during play, which either
spontaneously resolves or immediately responds to inhaled albuterol.
Oftentimes, the athlete self-medicates and never leaves play or alerts
the trainer or doctor. Although no clear-cut guidelines exist, a player
who is removed from play for an asthma attack should be kept out of
play until his or her respiration has normalized. This should occur
within 5-10 minutes of medication administration. The athlete should be
monitored closely for signs of relapse over the next several hours. If
the symptoms do not completely resolve with sideline medication, the
athlete should not return to play and should be referred for further
treatment. Depending on the severity of the patient's symptoms, this
may require transportation via ambulance.
Complications
Complications of an untreated asthma attack include status
asthmaticus, respiratory failure, and even death. More commonly, an
anxiety attack can be precipitated secondary to dyspnea.
Prevention
The optimal treatment of EIA is to prevent the onset of symptoms. See the Medication section for a discussion of drugs used to prevent EIA.
Prognosis
The prognosis is excellent for athletes with asthma. With proper
interventions, most symptoms can be prevented, and performance should
not be limited by EIA if this condition is treated properly. Newly
diagnosed young athletes need to be educated that this condition should
not be perceived as an insurmountable disability. Using examples of the
numerous elite athletes (eg, Jackie Joyner-Kersee [perhaps the world's
greatest athlete]; Amy Van Dyken [Olympic swimmer]; Jerome Bettis
[former running back for the Pittsburgh Steelers]) with this condition
can help young impressionable athletes continue in their endeavors
without fear of failure or medical distress.
Education
Patient education is a critical part of the treatment of EIA. Once
the diagnosis is made, athletes should be encouraged to continue in
their activities with the reassurance that proper treatment can allow
for an unhampered performance for most individuals. In addition to
reassurance, it is also important to teach individuals to recognize the
signs of an impending attack. Once recognized, individuals should be
taught to remove themselves from the aggravating activity and initiate
treatment as necessary. This includes education about the proper choice
of agents to abort an acute attack (ie, albuterol), but not cromolyn,
salmeterol, or an inhaled steroid. Teaching the proper mechanics of
inhalant medication administration is also important, along with, if
needed, teaching and demonstrating the proper use of a spacer device to
the patient; without the proper mechanics in using such devices, the
medication does not reach the area of pathology and does not benefit
the athlete. For excellent patient education resources, visit eMedicine's Asthma Center. Also, see eMedicine's patient education articles Asthma, Asthma FAQs, and Exercise-Induced Asthma.
Medical/Legal Pitfalls
- Downplaying of symptoms: The common pitfalls occur with
downplaying of symptoms or patient complaints. Education of the
coaching staff is crucial because coaches need to know that shortness
of breath in athletes does not always indicate poor conditioning and
that the consequences of ignoring an asthma attack can be serious.
- Missed
diagnosis: The physician, trainer, or other medical staff must always
consider bronchospasm in athletes with the previously described
complaints. A high index of suspicion diminishes the possibility of
missed diagnoses. A thorough knowledge of the differential diagnosis
(see Differentials) and how to work up the possibilities are also important (see Workup).
Special Concerns
- Pregnancy: Although most of the commonly used drugs are
in pregnancy category C, these agents are often used for asthma, which
is a common condition of pregnancy.
- Pediatric population: Many
of the agents used for asthma are not indicated for children younger
than 2 years; other agents are not indicated for children younger than
6 years. However, these medications have been used successfully for
decades in the management of childhood asthma and should be used for
children with EIA.
- Other/general: The highly driven,
high-performing adolescent athlete, especially the female athlete, is
at high risk for vocal cord dysfunction. This condition can be confused
with EIA but does not respond to the same treatment. Professionals
caring for athletes must keep a high index of suspicion for vocal cord
dysfunction. (See also the eMedicine article Vocal Cord Dysfunction.)
- National Heart, Lung,and Blood Institute, National Asthma Education and Prevention Program. Expert Panel Report 3:Guidelines for the Diagnosis and Management of Asthma: Full Report 2007. Bethesda, Md: NHLBI; August 2007. Publication no. 07-4051. [Full Text].
- Anderson SD. How does exercise cause asthma attacks?. Curr Opin Allergy Clin Immunol. Feb 2006;6(1):37-42. [Medline].
- Hough DO, Dec KL. Exercise-induced asthma and anaphylaxis. Sports Med. Sep 1994;18(3):162-72. [Medline].
- Beaudouin E, Renaudin JM, Morisset M, et al. Food-dependent exercise-induced anaphylaxis--update and current data. Allerg Immunol (Paris). Feb 2006;38(2):45-51. [Medline].
- Stensrud T, Berntsen S, Carlsen KH. Exercise capacity and exercise-induced bronchoconstriction (EIB) in a cold environment. Respir Med. Jul 2007;101(7):1529-36. [Medline].
- Butcher JD. Exercise-induced asthma in the competitive cold weather athlete. Curr Sports Med Rep. Dec 2006;5(6):284-8. [Medline].
- Dickinson JW, Whyte GP, McConnell
AK, Harries MG. Screening elite winter athletes for exercise induced
asthma: a comparison of three challenge methods. Br J Sports Med. Feb 2006;40(2):179-82; discussion 179-82. [Medline].
- Wilson JJ, Wilson EM. Practical management: vocal cord dysfunction in athletes. Clin J Sport Med. Jul 2006;16(4):357-60. [Medline].
- Kenn K. [Vocal Cord Dysfunction--what do we really know? A review] [German]. Pneumologie. Jul 2007;61(7):431-9. [Medline].
- Kaplan TA. Exercise challenge for exercise-induced bronchospasm: confirming presence, evaluating control. Phys Sports Med. 1995;23(8):47-57.
- Rundell KW, Anderson SD, Spiering
BA, Judelson DA. Field exercise vs laboratory eucapnic voluntary
hyperventilation to identify airway hyperresponsiveness in elite cold
weather athletes. Chest. Mar 2004;125(3):909-15. [Medline]. [Full Text].
- Storms W. Update on montelukast and
its role in the treatment of asthma, allergic rhinitis and
exercise-induced bronchoconstriction. Expert Opin Pharmacother. Sep 2007;8(13):2173-87. [Medline].
- Steinshamn S, Sandsund M, Sue-Chu
M, Bjermer L. Effects of montelukast and salmeterol on physical
performance and exercise economy in adult asthmatics with
exercise-induced bronchoconstriction. Chest. Oct 2004;126(4):1154-60. [Medline]. [Full Text].
- Beuther DA, Martin RJ. Efficacy of a heat exchanger mask in cold exercise-induced asthma. Chest. May 2006;129(5):1188-93. [Medline]. [Full Text].
- Knöpfli BH, Luke-Zeitoun M, von
Duvillard SP, et al. High incidence of exercise-induced
bronchoconstriction in triathletes of the Swiss national team. Br J Sports Med. Aug 2007;41(8):486-91; discussion 491. [Medline].
- Koh MS, Tee A, Lasserson TJ, Irving
LB. Inhaled corticosteroids compared to placebo for prevention of
exercise induced bronchoconstriction. Cochrane Database Syst Rev. 2007;3:CD002739. [Medline].
- Lacroix VJ. Exercise-induced asthma. Phys Sports Med. 1999;27(12):75-92.
- McFadden ER Jr, Gilbert IA. Exercise-induced asthma. N Engl J Med. May 12 1994;330(19):1362-7. [Medline].
- National Asthma Education and Prevention Program. Expert Panel Report: Guidelines for the Diagnosis and Management of Asthma - Update on Selected Topics 2002. Bethesda,
Md: National Institutes of Health and National Heart, Lung, and Blood
Institute; June 2003. NIH publication no. 02-5074. [Full Text].
- Parsons JP, Kaeding C, Phillips G, ET AL. Prevalence of exercise-induced bronchospasm in a cohort of varsity college athletes. Med Sci Sports Exerc. Sep 2007;39(9):1487-92. [Medline].
- Smith BW, MacKnight JM. Pulmonary. In: Safran MR, McKeag DB, Van Camp SP, eds. Manual of Sports Medicine. Vol 1. Philadelphia, Pa: Lippincott-Raven; 1998:244-9.
- Storms WW. Asthma associated with exercise. Immunol Allergy Clin North Am. Feb 2005;25(1):31-43. [Medline].
运动性哮喘可发生在任何年龄，在儿童和成人的哮喘患者中都很常见。它可影响儿童的玩耍和游戏，影响所有年龄组患者的体育运动质量，影响他们的生活和工
作。运动性哮喘的临床表现和其它形式的急性哮喘没有差别，只是发作的时间短暂。在大多数哮喘患者，除了气流梗阻外运动还可引起短暂的肺过度膨胀和低氧血
症。运动性哮喘不同于其它哮喘的一个特点是，运动激发后先引起支气管扩张，而后诱发支气管收缩，其它诱发因素只引起支气管收缩。
运动性哮喘是否为哮喘的一种类型还有争议。一般而言，支气管哮喘的特征是气道炎症和支气管平滑肌痉挛，但运动性哮喘主要是支气管平滑肌痉挛引起的。因
此，某些学者喜欢称其为运动性支气管痉挛，而不称为运动性哮喘。现在人们认为，运动性哮喘是哮喘患者反应性增高的气道对剧烈运动后过度通气刺激的反应。高
反应性的气道过度通气后失水和降温，使支气管黏膜上皮表面的液体渗透压升高，诱发了支气管痉挛，引起哮喘。因此将运动看成是一种哮喘的激发因素。大多数的
哮喘患者运动后都出现不同程度的运动性哮喘。但在临床上确实有一部分患者，运动是惟一的激发因素。大约有40％的变应性鼻炎的儿童没有临床哮喘的表现，但
表现为运动性哮喘。因此，有人认为运动性哮喘是支气管哮喘的一种特殊类型。
运动性哮喘是支气管哮喘中的一个特殊类型，它的发病一般认为在气道炎症和高反应状态下，运动时由于热量和水分丢失，过敏原等因素作用下，肥大细胞和嗜碱粒细胞等释放的血管活性介质对人体严重的、全身性的反应，并引起支气管痉挛导致哮喘发作。
正常人在突然运动或一定量体力活动后可以出现气促，但不出现哮鸣音，稍事休息后即可缓解，而一些人在运动当时或运动数分钟后，出现气喘，哮鸣音的急性哮喘发作，称为运动性哮喘（EIA）。
必须有一定的运动量才出现喘息，这是运动性哮喘的特点。最容易诱发哮喘的运动是跑步，尤其在冬日跑步，其次蹬车、上下阶梯，游泳的活动量虽然很大，却不容易引起运动性哮喘，虽然哮喘的严重度与运动量相关，但在连续运动后，哮喘的发作又会减轻或被抑制。
运动性哮喘的防治首先是对已知过敏原的回避，空气污染可引起通气频率的增加。因为运动可增加通过鼻腔的污染物的数量。二氧化硫（SO2）和冷空气在触发支
气管痉挛方面，可能有协同作用，主要的污染物是二氧化硫、一氧化碳、氧化亚氮等一些特殊物质。另外，儿童和其青少年早期吸烟的母亲的支气管高反应性与运动
性哮喘亦有关。其次是通过训练性调节，我国著名哮喘专家陈育智教授，每年组织的哮喘儿童夏令营，都是以游泳为主要运动项目，通过改变活动方式，增强了体质
并调节了免疫，身体耐受性得到改善，从而也减轻了症状。
药物治疗，包括在运动前和接触过敏原后，气雾剂β2受体激动剂（沙丁胺醇、喘乐宁、喘康速）为治疗的第一线药物，它可有效地阻止哮喘的发作和减轻发作后症
状，如在体育或运动前根据需要作一定量吸入。然而重要的是病因治疗中的抗炎（非特异性炎症），使用吸入型糖皮质激素（倍氯米松、必可酮、普米克都保）在医
生的指导下，坚持使用1－2年，会取得理想的效果，尤其儿童。
运动性哮喘通过科学防治，完全可以得到控制。1984年奥林匹克运动会上，一个公认的研究表明：患运动性哮喘的67名运动员中，有41名获得奖牌，说明患运动性哮喘的病人通过适当的治疗有能力成功地进行活动和比赛。（来源：中国哮喘网）
|
楼主
发表于 2008-4-30 01:04:14
发表于 2008-5-1 16:05:21
