Introduction
Asthma is a chronic disease that affects the respiratory system. According to World Health Organization (WHO), asthma is the most chronic disease in children, although it affects both children and adults. The disease is one of the major non-communicable diseases, with an estimated 262 million people having been affected in 2019, with a death toll of about 455,000 deaths reported (World Health Organization [WHO], 2022). The paper will examine the mode of action of the most common types of inhalants used in asthma treatment and make a comparison.
Corticosteroid Mode of Action
Corticosteroid inhalants consist of a class of hormones secreted by the adrenal gland. The role of these hormones is the regulation of physiological processes in the body. Corticosteroids work by binding their hormone to the specific intracellular receptors of the target cells. During binding, there is an initiation of a series of events that result in the inhibition of transcription of genes involved in the inflammation and immune response. The inhalant also modulates the production of various enzymes, cytokines, and mediators that contribute to the inflammatory response.
Corticosteroids also function through the direct inhibition of the activation and proliferation of immune cells like the T-cells and B-cells. Additionally, these hormones stimulate the secretion of anti-inflammatory mediators that help to further suppress the immune response. Lipocortin is an example of an anti-inflammatory mediator in the body. This mode of action makes these hormones the most preferred effective treatment option for allergies and other inflammatory health conditions.
Differences in Modes of Action
Corticosteroids and ß2-agonists are both used in the treatment of asthma and other respiratory diseases. Even though these drugs are used to serve the same function, each drug has a unique mode of action in the body. The mode of action for corticosteroids is the reduction of airway inflammation, which is a major contributor to asthma (O’Bryne et al., 2019). These hormones block the release of cytokines and other chemicals that cause inflammation, reducing the narrowing and swelling of airways. As a result, there is improved breathing and a reduction of the symptoms displayed by the disease.
On the contrary, the mode of action of ß2-agonist inhalants is the relaxation of the airway smooth muscle. As a result, the airways widen, causing improved airflow to the lungs and reducing other symptoms of the disease. These inhalants are commonly used where quick relief is needed from symptoms such as shortness of breath, chest tightness, and wheezing. However, unlike the corticosteroids that also help in reducing inflammation, the ß2-agonist only provides rapid relief of the symptoms.
Cause of Fatigue
Asthma is characterized by inflammation and narrowing of the airways. As a result, the patient may experience breathing difficulties, shortness of breath, and wheezing. In a prolonged asthmatic attack, the airways become completely obstructed, making the inhalation of a sufficient amount of oxygen a problem for the patient. This results in a condition, called hypoxia, where the patient’s body contains high amounts of carbon dioxide and is deprived of oxygen supply, causing fatigue and body weakness.
In addition, increased efforts by the patient to breathe during the attacks result in rapid breathing and increased heart rate, which may overwork the heart and lung muscles. The result may cause fatigue and physical exhaustion, reAttacksulting in difficulties for the patient in carrying out strenuous activities. Additionally, increased contraction and relaxation of the muscles in the airway in a bid to maintain a continuous airflow may cause body fatigue.
Psychologic Events during an Asthmatic attack
There is a range of psychological events and emotional responses that a patient may experience during a prolonged asthmatic attack. Firstly, most asthmatic attacks are unpredictable and frightening, especially where prior attacks have resulted in serious complications. Thus, patients may be overcome by fear and anxiety during the attack (Schwartz et al., 2022). This is mostly the case where the patient has had past severe attacks or is in fear of suffocation. Emmanuel became anxious as he tried gasping for air. Secondly, sudden asthmatic attacks can cause the patient to panic and become overwhelmed by a sense of dread. In this case, Emmanuel was experiencing difficulties in breathing and gasping for air. In such a case, the distress associated could result in a build-up of feelings of panic.
Stress is also associated with asthmatic attacks. Stress affects both the patient and the caregiver. Asthmatic attacks cause an individual to feel helpless and out of control, which could cause stress. Most people with asthmatic conditions also feel embarrassed and ashamed of the condition, especially when the patients are unable to cope or feel like others perceive them as weak (Schwartz et al., 2022). This may cause the individuals to isolate and withdraw from society, especially in social situations that make them vulnerable or that are beyond their ability to engage.
Oxygen Compensation during Hypercapnia
During a prolonged asthmatic attack, carbon dioxide levels in the body increase while the intake of oxygen is lowered. This results in hypercapnia, a condition in the body that causes an increase in the acidity in the blood (Strapazzon et al., 2018). The body has several mechanisms to compensate for the low oxygen levels. During an attack, the primary body reaction is increasing the rate and the depth of breathing to facilitate the removal of the excess CO2 levels in the blood.
Additionally, the blood vessels vasodilate to increase blood flow and facilitate the distribution of excess CO2 throughout the body. Buffer systems like the hemoglobin and bicarbonate-carbonic acid buffer systems help to neutralize the effects of increased levels of CO2 in the blood (Strapazzon et al., 2018). Moreover, the kidneys produce bicarbonate and other substances that facilitate the neutralization of the acidity in the blood. There is also stimulation of the medulla oblongata that regulates breathing, causing an increase in the respiratory effort.
Effect of Hypercapnia on the Central Nervous System (CNS)
Hypercapnia results in the elevation of CO2 levels, which can have significant effects on the CNS. Since CO2 is a potent vasodilator, elevated levels result in blood vessel dilation, increasing cerebral blood flow. The increase in blood flow increases pressure inside the skull, causing brain swelling and an increase in intracranial pressure (Shigemura et al., 2020). Elevated CO2 levels also interfere with the normal functioning of the CNS, which may cause the patient to experience symptoms such as confusion, impaired thinking, dizziness, and headaches.
Hypercapnia also interferes with the normal functioning of body cells, especially the nerve cells, causing neurological symptoms such as impaired movement, tremors, and general muscle weakness. In most severe cases, the condition results in respiratory depression, causing the patient to experience difficulties in breathing and a lack of oxygen in the brain (Shigemura et al., 2020). Without prompt treatment, the patient can fall into a coma or die.
Conclusion
Asthma is one of the most common chronic diseases in the world. The major cause of the condition is inflammation and narrowing of the airways in the lungs. Medications for this condition include corticosteroids, whose main cause of action is the reduction of inflammations in the airway and ß2-agonist, whose action is the relaxation of the muscles in the airways. Even though the body has response mechanisms to respond to hypercapnia, prompt medical attention should be administered in case of an attack.
References
O’Byrne, P., Fabbri, L. M., Pavord, I. D., Papi, A., Petruzzelli, S., & Lange, P. (2019). Asthma progression and mortality: The role of inhaled corticosteroids. European Respiratory Journal, 54(1), 1900491. Web.
Schwartz, A. E., Beemer, L. R., Ajibewa, T. A., Scott-Andrews, K. Q., Lewis, T. C., Robinson, L. E., & Hasson, R. E. (2022). Psychological responses to intermittent activities in children with and without asthma. Pediatric Exercise Science, 34(4), 175–184. Web.
Shigemura, M., Homma, T., & Sznajder, J. I. (2020). Hypercapnia: An aggravating factor in asthma. Journal of Clinical Medicine, 9(10), 3207. Web.
Strapazzon, G., Putzer, G., Dal Mulino, M., Braun, P., Helbok, R., Falk, M., Mair, P., & Brugger, H. (2018). Effects of hypothermia, hypoxia and hypercapnia on brain oxygenation – A prospective porcine study. Resuscitation, 130, e141. Web.
World Health Organization. (2022). Asthma. Web.
