Asthma
Introduction
Asthma is a chronic inflammatory disorder of the airways, which leads to airflow obstruction, airway hyperresponsiveness and disease chronicity (Lugogo & Maclntyre, 2008). Common signs and symptoms of asthma include wheezing, coughing, shortness of breath and chest pains or tightness. Doctors associate these symptoms to the widespread but variable airflow obstruction that is reversible with treatment. Studies into the pathogenesis of asthma are still underway, but the central phenotypic pattern of asthma is the presence of airway inflammation, which represents different aspects of the disease. These aspects include acute versus chronic manifestations of asthma.
Pathophysiology mechanisms of asthma
The pathophysiology of chronic asthma and acute asthma exacerbation is complex, and it involves various mechanisms, such as, airway inflammation, bronchoconstriction and airway obstruction. The dominant physiological event is airway inflammation, which involves an interaction of many cell types, and multiple mediators with the airway, which results in characteristics of pathophysiological features of asthma. The principle cells identified in airway inflammation include mast cells, eosinophils, epithelial cells, activated T lymphocytes and macrophages. Acute asthma exacerbations associate largely with substantial airway inflammation. Arterial blood gas analysis is a prime indicator of levels of acute asthma exacerbation, where arterial blood gas levels decline with worsening acute exacerbations (Lugogo & Maclntyre, 2008).
Secondly, bronchoconstriction is the narrowing of the airway following the contraction of the bronchial smooth muscle, subsequently interfering with the airflow. In acute asthma exacerbations, bronchoconstriction occurs in response to exposure to various stimuli, such as, allergens. Thirdly, airflow obstruction is a pathophysiological mechanism caused by acute bronchoconstriction, airway edema and chronic mucous plug formation. Airflow obstruction leads to increased resistance t airflow and decreased expiratory flow rates. Consequently, there is a reduced ability to expel air, which leads to hyperinflation.
Diagnosis and treatment
Basing on the factor of airway inflammation, correct diagnosis of asthma involves the establishment of the presence of episodic symptoms of airflow obstruction, that airflow obstruction is partially reversible and the exclusion of other alternative diagnosis. The primary test for patients with acute asthma exacerbations is the pulse oximetry measurement, which is applicable to exclude hypoxemia. The test for chronic asthma is the spirometry with postbronchodilator response. However, the most prevalent imaging evaluation for asthma patients is the chest radiograph. After diagnosis, prescribed treatment for asthma is pharmacologic treatment, which involves use of control agents, such as, long-acting bronchodilators and inhaled corticosteroids, and relief medications, such as systematic corticosteroids, ipratropium and short-acting bronchodilators (Lugogo & Maclntyre, 2008).
Mind maps
| Chronic asthma |
Epidemiology
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Clinical presentation
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Pathophysiology
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Diagnosis
Treatment
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| Acute asthma exacerbation |
Pathophysiology
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Clinical presentation
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Diagnosis
Treatment
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Epidemiology
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Conclusion
In conclusion, the management of acute and chronic asthma is complex, thus necessitating the need to understand its phenotypes and pathophysiology, which enables its management and reduction in its morbidity and mortality (Lugogo & Maclntyre, 2008).
References
Lugogo, N. L., & MacIntyre, N. R. (2008). Life-threatening asthma: pathophysiology and management. Respiratory care, 53(6), 726-739.
