AUTHOR AND EDITOR INFORMATION
Section 1 of 10 
引用第11楼annaijing于2008-04-30 01:04发表的: 如果不是很尖锐的疼痛而且只是在运动后发生的话应该没什么的，可能只是热身不够而已 to sam神：你不会觉得pengyou这种体型会气胸吧？@@
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],
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
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.)
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.
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.
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 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.
Deconditioning syndrome
Seasonal asthma (See also the eMedicine article Allergic and Environmental Asthma.)
Upper airway obstruction (See also the eMedicine article Stridor.)
(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.)
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].)
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.
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:
If the initial response to treatment was adequate, patient observation and monitoring need to continue for several hours in case of a relapse.
If patient relapse is immediate, transportation to an emergency facility should be initiated.
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.
Long-term treatment of EIA is prevention of the condition (see Medication).1
Nonpharmacologic measures can also be taken in the treatment of EIA.
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).
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. |
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. |
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. |
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. |
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. |
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 |
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 of an untreated asthma attack include status asthmaticus, respiratory failure, and even death. More commonly, an anxiety attack can be precipitated secondary to dyspnea.
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.
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.
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.
引用第13楼sam神于2008-05-01 16:05发表的: 我還不知道他的體型是怎樣的？能发將照片看看嗎？pengyou,我有見過你嗎？
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