Exercise-induced asthma is a feeling of shortness of breath, with the presence of cough, wheezing, and chest tightness after physical exercise.
Normally the bronchial tree and bronchial vessels responds to exercise with increasing radius of the interior of the bronchi (bronchodilation), but those affected by exercise-induced asthma occurs otherwise narrow and produces bronchoconstriction.
Exercise Induced Asthma Causes
The exercise-induced asthma (EIA) is due to cooling and drying air relative (loss of H2O) by increased ventilation during exercise. The cooling and drying cause changes in the osmolarity of the mucosa, leading to one hand, there is a mast cell degranulation with release of mediators, and second, to the occurrence of direct vagal stimulation. The result is the emergence of bronchoconstriction.
There are some other factors that may trigger Exercise Induced Asthma:
* Cold air inspired
* Low humidity of inspired air,
* Loss of heat from the air.
Exercise Induced Asthma Symptoms
The defining characteristics of the Exercise Induced Asthma are:
* Can occur at any age, and is as common in adults and children. Fleshy settings (wide body constitution) are prone.
* It may appear isolated or associated with any clinical form of bronchial asthma. In most asthmatics, exercise causes bronchoconstriction or exercise induced bronchospasm.
* The severity of EIA is not predictable from baseline function. Patients with normal lung function at rest may have important IEA.
* Phase characteristics of the IEA:
Bronchodilatation or initial (asymptomatic). As in non-asthmatics, in patients with asthma exercise initial bronchodilation occurs without symptoms.
Bronchospasm or clinical. After 5-10 minutes after the effort began, when the heart rate reaches about 160 beats per minute, appears bronchoconstriction.
or recovery phase. Between 30 and 60 minutes after starting the exercise, it begins a return to normality in bronchial caliber and dyspnea disappears.
or refractory period. In more than half the cases of EIA, there is a period of 2 to 4 hours’ duration, during which it will revert to the bronchospasm, although it should be continue to exercise. The refractory period is due to depletion of mediators of bronchoconstriction and / or generation of bronchodilator prostaglandin (PGE2) during exercise. The refractory period can be induced by preheating, and used for the asthma is not impaired athletic performance.
* The EIA can be prevented by inhalation or after taking certain medications. Are used for this purpose ß2-mimetic action short and long cromolyn, and leukotriene inhibitors.
