A Comprehensive Exploration of Asthma

Asthma is a chronic lung disease marked by chest tightness, wheezing, breathlessness, and coughing (Dodge & Burrows, 2018). In the United States alone, there are 19 million adults and 6.2 million children living with asthma (Centers for Disease Control and Prevention, 2018). The disease can be managed by avoiding triggers and correctly using the prescribed medication. Asthma can either be acute or chronic. The purpose of this paper is to describe the pathophysiological mechanisms of both chronic asthma and acute asthma exacerbation, explain the changes in the arterial blood gas patterns during an exacerbation, and explain how age might impact the pathophysiology of both disorders.

Acute Asthma

Acute asthma exacerbation, also called asthma attack, occurs when the patient is exposed to an allergen, which triggers the attack. The trigger can be anything from pollen, mold, cat tender, to tobacco smoke. The antigen of the allergen binds with a mast cell that degranulates and releases inflammatory mediators, which includes bradykinins, histamine, prostaglandins, interleukins, and leukotrienes (Lemanske & Busse, 2017). These mediators initiate bronchospasm of the smooth muscles of the airway. Increased capillary permeability causes edema which constricts the airway making it difficult to breathe. Air trying to pass through the narrowed airway makes the wheezing sound.

When asthma attacks, its severity varies. Severe attacks warrant a more intensive treatment, which can include intubation. To determine the severity of the attack, one of the tests that can be done is arterial blood gas (ABG). It measures the measures oxygen, carbon dioxide and the pH levels in the blood and evaluates the effective delivery of oxygen to the blood by the lungs and effective elimination of the carbon dioxide by the lungs. The values obtained from the

Chronic Asthma

Asthma is considered as a chronic disorder of the airways even though some asthma symptoms that begin in childhood can cease to appear in adulthood. Children with severe asthma are, however, less likely to outgrow it. It is, therefore, important to diagnose it early so that it can be better managed. Identifying the triggering allergen that causes airway obstruction is a very important step in the management of the condition. Airway obstruction can either be a result of inflammation, bronchospasm or luminal obstruction caused by hypersecretion of mucus. Asthma can be a result of host factors, environmental factors or both. Host factors may include gender, obesity, and genetics. Asthma can be atopic or nonatopic. According to Holgate (2017), atopic asthma begins in childhood and is linked with triggers that initiate wheezing. It can arise from exposure to an allergen such as pollen. The exposure triggers the release of IgE which binds to cells related to inflammation. When this happens, inflammatory mediators such as cytokine triggers inflammation and bronchoconstriction. Nonatopic asthma on the other hand, usually occurs in adults and does not involve IgE. The triggers are not usually as a result of a viral infection.

Impact of Gender on Pathophysiology

Gender has been determined to be a factor in asthma prevalence. Boys also have a smaller airway diameter relative to lung volumes compared to girls, making boys more likely to have asthma symptoms than girls…………….. As children, boys are twice as likely to be hospitalized for asthma exacerbation than girls, but this changes when they get to adolescence (Mandhane, et al., 2015). This finding goes in line with the mild asthma onset in childhood, which is more prevalent in boys but disproportionately turns severe later in females. As adults, women, therefore, have an increased asthma prevalence than men. Recent clinical findings show that starting from puberty, females begin to show increased asthma symptoms compared to men. According to Wright et al. (2016), animal studies showed that Th2-mediated airway inflammation is increased by estrogen and decreased by testosterone. How ovarian hormones and testosterone regulate other pathways important in airway inflammation, however, remains to be explained. According to Thomas, Lemanske, & Jackson (2014), approximately 30–40% of women with asthma report pre or peri-menstrual worsening of asthma symptoms.

Diagnosis and Treatment

Asthma diagnosis can be based on patient history, physical examination, and diagnostic testing. Among the diagnostic testing indicated for asthma, are Peak Expiratory Flow (PEF), Spirometry, Exhaled Nitric Oxide, Bronchial provocation, and X-ray. Some of these tests are not definitive but can aid in the diagnosis; exhaled nitric oxide, for instance, tests the presence of nitric oxide, a gas produced in the lungs when there is inflammation. Asthma is an inflammatory process, but there are many other inflammatory conditions.

Asthma management can either be pharmacological or non-pharmacological. Some of the non-pharmacological treatments include avoidance of known environmental triggers, having an action plan which details signs of worsening symptoms and what to do, and a good medication and health literacy, which includes a good understanding of the condition and the use of prescribed medication. On pharmacological management, asthma medications are divided into two categories: Short-term symptom relief (rescue) and long-term management. In the rescue category, albuterol is the most prescribed, and it comes as a dry powdered inhaler, metered-dose inhaler, and nebulizer. For long term management, inhaled corticosteroids are the drugs of choice.

Conclusion

Asthma is a chronic lung disease that affects over 25 million people in the US. It marked with chest tightness, wheezing, coughing, and breathlessness. It usually lasts a lifetime, but a few children outgrow it. It can either be acute or chronic. Acute asthma, also called asthma attack, can be triggered by an allergen, which causes mediators like histamine and cytokines to initiate bronchospasm and inflammation of the airway. One of the factors that affect the prevalence and pathophysiology of asthma is gender. Boys have a smaller airway diameter relative to lung volumes compared to girls, making boys more likely to have asthma symptoms than girls as children, but these changes in adolescence. Starting from puberty, females begin to show increased asthma symptoms compared to their male counterparts. Approximately 30–40% of women with asthma report pre or peri-menstrual worsening of asthma symptoms. Asthma diagnosis can be based on patient history, physical examination, and diagnostic testing. Asthma management can either be pharmacological or non-pharmacological. Some of the non-pharmacological treatments include avoidance of known environmental triggers and having an action for when an exacerbation occurs. Pharmacological management involves short-term symptom relief and long-term management. The most prescribed rescue medication is albuterol, and for long term management, inhaled corticosteroids are the drugs of choice.

References

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8. Thomas, A., O., Lemanske, R.., F., & Jackson, D., J. (2014). Infections and their role in childhood asthma inception. Pediatr Allergy Immunol. 2014; 25: 122–128
9. Wright, A., L., Stern, D., A., Kauffmann, F., et al. (2016). Factors influencing gender differences in the diagnosis and treatment of asthma in childhood: the Tucson Children's Respiratory Study. Pediatr Pulmonol 2016; 41:318–25.