Asthma Pathophysiology | Nursing Assignment

Nursing Assignment

Part A
Introduction:
Asthma is a chronic allergic, immune mediated and inflammatory disease. Main signs and
symptoms of asthma comprises of shortness of breath, increased respiratory rate, difficulty in
breathing, coughing and wheezing. Occurrence of asthma is more in children which is known as
childhood asthma. Etiological factors of asthma include cold air, exercise, pollen, viruses,
genetic factors, drugs like aspirin and beta blockers. Asthma attacks can occur in many occasions
in a single day or on few days in a week. Approximately, 1 in 9 people in Australia have asthma.
It is more common in male below 14 years of age, however it is more common in female above
14 years of age. Asthma is prevalent in the older and Indigenous Australians also. Asthma is
more prevalent in people with low socioeconomic class. Asthma is a huge financial and social
burden in Australia. 451 per 100,000 population children fewer than 15 years age are
hospitalized due to asthma. Approximately 400 deaths per year occurs due to asthma in Australia
in last 10 years. 34 % people reported interference in daily activities due to asthma and 21 %
children reported off form school or work due to asthma (AIHW, 2016). In this essay, case of 6
years old Zachy is discussed, who is suffering through coughing, wheezing and difficulty in
breathing. Signs and symptoms of Zachy are correlated with pathphysiological changes of
asthma.
Discussion:
Asthma pathophysiology can be studied in four different categories like bronchoconstriction,
airway edema, airway hyperresponsiveness and airway remodeling. Inflammation of the airways
leads to the bronchoconstriction. Type 1 hypersensitivity reactions are responsible for the
initiation of the asthma attack. Allergens are processed by antigen presenting cells and these are
presented to the naïve T lymphocytes like Th0 cells. Th0 cells switch to the Th2 cells after
presentation of the allergens. Th2 cells release different cytokines like IL-4 and IL-13. These
cytokines act on the B lymphocytes to produce immunoglobulin E. These IgE bind to the Fc
receptors present on the mast cells. Binding of the IgE to the receptors on the mast cells is
termed as the sensitization phase of asthma (Bonini and Usmani, 2015). When there is repeated
attack of same allergens in the same person, newly entered allergens bind to the IgE and Fc
receptors complex on the mast cells. This binding leads to the degranulation of the mast cells.

This degranulation of the mast cells lead to the release of different mediators like histamine,
leucotrines and prostaglandins. These mediators produce contraction of the airway smooth
muscle and consequently narrowing of airways and bronchoconstriction. These mediators can
also be released by IgE independent pathway. Aspirin and non-steroidal anti-inflammatory drugs
are responsible for the IgE independent pathway. Bronchoconstriction can also be induced by
physical factors like cold, excercise and irritants. Stress is also responsible for
bronchoconstriction in asthma (Erjefält, 2010).
Inflammation in the asthma can be produced due to inflammatory cells like Th2 lymphocytes,
mast cells, eosinophils, dendritic cells, epithelial cells, macrophases and resident cells of airway.
Progressive and chronic inflammation of the airways can result in the edema formation in the
airways. Mucus hypersecretion and deposition of mucus plugs in the airways can occur due to
inflammation. Sustained inflammation leads to the hypertrophy and hyperplasia of the airways.
This results in the reduced airflow through the airways. Sustained inflammation and the
structural changes in the airways lead to the airway hyperresponsiveness (Patadia et al., 2014).
Airway remodeling comprises of permanent structural changes in the airways which can lead to
the loss of lung function. Features of airway remodeling are sub-basement membrane thickening,
subepithelial fibrosis, hypertrophy and hyperplasia of airway smooth muscle, proliferation and
dilation of blood vessels, mucous gland hyperplasia and mucus hypersecretion. Due to loss of
lung function, there can be insufficient breathing. Insufficient breathing lead to the less exchange
of oxygen at the alveoli and blood capillaries interface. As a result, there is less oxygen in the
blood and less oxygen saturation. In case of Zachy also, less oxygen saturation observed. In
children of Zachy’s age oxygen saturation should be above 95 %, however in case Zachy oxygen
saturation level is 92 %. Due to low level of oxygen in the blood, lung tries to compensate it by
inhaling more air which leads to increase in breathing rate. As a result, there is increase in
respiratory rate in asthma patients. In case of Zachy also, there is increased respiratory rate. In
children of Zachy’s age respiratory rate should be below 20 breath per minute, however it was
observed that in case of Zachy respiratory rate is 37 breaths per minute (Mims, 2015; Chawes,
2011).
Cough can be of two types productive cough and non-productive cough. Productive cough expels
phlegm and it act as defense mechanism. Non-productive cough is dry cough and it occurs due to
irritation of the inflamed airways and constricted airways. In asthma patients, non-productive

cough occurs. If cough is accompanied by other signs and symptoms like chest tightness,
wheezing, fatigue, long duration infection and breathing difficulties, it is considered as cough
due to asthma. In asthma children, there are more incidences of cough in the night (Patadia et al.,
2014). In case of Zachy also, cough is more in the night time. Wheezing is the whistling like
sound of exhaled air. By force passage of air through narrow and constricted airways produces
wheezing sound in the Zachy. Wheezing can be of two types like transient and persistent
wheezing. If wheezing stops at age of 3 years, it is called as transient wheezing. If wheezing
continues after age of 5 years, it is called as persistent wheezing. In case of Zachy, there is
persistent wheezing (West et al., 2013; Krishnan et al., 2012).
Conclusion:
Asthma is a multifactorial disease with diverse etiological factors. Asthma is a very common
disease in children and associated with nocturnal cough. Pathophysiological changes associated
with asthma are inflammation of airways, bronchospasm and airway remodeling. Zachy
exhibited symptoms of asthma like rapid respiratory rate, coughing, wheezing and low oxygen
saturation level with respect to the pathological changes. Multiple mechanisms are involved in
the pathogenesis of asthma and these different mechanisms exhibit respective symptoms. For the
management of symptoms of asthma nurse should have sound knowledge of relevant
pathophysiological mechanisms.