Asthma and Its Management in Elderly

Introduction

The function of the respiratory system is to help in the process of respiration. This process not only helps in gaseous exchange but also maintains the balance of the gases in the bloodstream. As a result, it is one of the essential processes for living. However, in certain cases, the gaseous exchange is compromised, leading to breathing difficulties. Lung disorders like asthma are one of the most common reasons for breathing problems.

What Is Asthma?

Asthma is a chronic inflammatory respiratory disorder. Obstruction and narrowing of the respiratory tract are responsible for such a condition. Such obstructions are caused by excessive production of mucus and bronchoconstriction. The prevalence rate of asthma is high in developing countries. Around 15 to 20 percent of the people living in developing countries suffer from asthmatic disorders compared to only two percent of people living in developed countries. In most cases, the asthmatic disorder is diagnosed before the age of 18. The causative factors associated with asthma are;

• Family history and genetic factors.

• Environmental substances that may cause allergies are dust and pollen.

• Respiratory tract infections are caused by viruses.

• Habits like smoking.

• Obesity.

• Stress, anxiety, and mental trauma.

• Use of drugs.

All these factors lead to the release of IgE antibodies by the plasma cells (a type of immune cell). This antibody binds to cells like basophils and mast cells, leading to the release of inflammatory mediators like histamine, prostaglandins, and cytokines. These mediators cause the accumulation of more inflammatory cells in the respiratory tract and the constriction of smooth muscles of the respiratory tract. As a result, the narrowing of the respiratory tract, along with the accumulation of mucus in the respiratory tract, is observed. These factors cause asthma and respiratory disorders.

What Is Asthma in the Elderly?

As already discussed, asthma is mainly seen in younger individuals. Asthma in elderly people is a rare entity. Only 3.1 people among 1000 elderly individuals suffer from asthmatic disorder. However, in most cases, asthma is superimposed by other pulmonary disorders. The risk factors that are associated with elderly asthmatic disorders are;

Chronic Obstructive Pulmonary Disorder (COPD): This is a common noninfectious inflammatory lung disorder that is primarily caused by smoking, secondary smoking, and exposure to harmful substances such as toxic gasses, metals, and chemicals. The presence of COPD leads to asthma-COPD overlap syndrome (ACOS). This is caused by neutrophilic inflammation, cytokine release, oxidative stress, DNA (deoxyribonucleic acid) methylation alterations, and matrix metalloproteinase-mediated proteolysis in individuals with asthma. Some researchers believe that genetic factors play a pivotal role in this process. The clinical features of this disease are the following:

1. The onset of this condition is often seen after the age of 40. However, patients usually have mild to moderate symptoms of respiratory distress since childhood.

2. There should be a history of persistent smoking or inhalation of toxic substances in the workplace.

3. The symptoms of breathing difficulties are four or five times higher in comparison to asthma or COPD. Similar symptoms like breathlessness, cough, and sputum production. A wheezing sound during respiration can be audible.

Aging Lungs: Age-related changes may complicate breathing problems. Due to aging changes like decreased lung functions, forced vital capacity (FVC), and forced expiratory volume in one second (FVC1) are observed. Such changes are caused by the alveolar epithelium undergoing morphological changes. These changes are responsible for a mismatch between ventilation and perfusion. Other factors that are associated with breathing complications are lung disorders, poor ventilation, limited air exchange in the alveoli, reduced mucociliary transport, weakened cough reflex, and decreased alveolar elasticity, which contributes to an increased susceptibility to lung infections.

Menopause and Hormone Replacement Therapy (HRT): Sex hormones play a protective role in preventing exacerbation of asthmatic events. Menopause is responsible for hormonal dysregulation. As a result, post-menopausal women have an increased prevalence of asthma. Women who are receiving hormone replacement therapy are also susceptible to asthma attacks.

What Are the Clinical Symptoms?

The clinical symptoms of asthma are similar to those of young individuals. However, in some cases, certain differences are observed. The symptoms of elderly asthma are;

1. Patients complain of episodic events of respiratory difficulty, chest tightness, and shortness of breath.

2. Wheezing sound during respiration is common.

3. Asthma events are commonly seen at night.

4. Elderly asthmatic events are often accompanied by upper respiratory tract infections and viral infections.

5. Asthma is frequently caused by environmental factors, including aeroallergens, irritants like cigarette smoke, household aerosols, and paints, strong odors such as perfumes, and the inhalation of metabisulfites present in beer, wine, and food preservatives.

6. Certain drugs like Aspirin, nonsteroidal anti-inflammatory agents, angiotensin-converting enzyme inhibitors, or beta-blockers may also cause asthma attacks.

The diagnostic tests done for diagnosing asthma are;

1. Spirometry: This is a common test for evaluating lung functions and lung capacity. This helps to measure the amount of obstruction present in the obstructive lung disease. Different parameters of lung function, like forced vital capacity (FVC) and forced expiratory volume in one second (FVC1), and the ratio between these two is determined.

2. Fractional Exhaled Nitric Oxide (FeNO) Test: It helps in assessing the intensity of inflammation in asthma. A test result exceeding 50 ppb indicates a substantial level of inflammation. If the result falls between 25 to 50 ppb, it suggests a moderate level of inflammation in asthma. A value below 25 ppb is associated with a low level of inflammation. The level of nitric oxide in patients with COPD (chronic obstructive pulmonary disease) is moderately elevated.

What Are the Treatment Options?

The treatment option for asthma in elderly people is similar to that of young individuals. Corticosteroids are the most commonly used drug for this purpose. However, inhaled corticosteroids are most commonly used in high doses. Prolonged use of these drugs may cause complications like bone resorption and immune suppression. Apart from this, drugs like leukotriene-modifying agents such as Montelukast, Zafirlukast, and Zileuton can be used in patients suffering from allergy-induced asthma or aspirin-induced asthma. Injectable biologics are also effective against older individuals. Drugs like Omalizumab can improve complications associated with asthma.

Conclusion

Asthma is caused by obstruction of the respiratory tract due to inflammation. In elderly people, diagnosing asthma is difficult due to its superimposition with other disorders. However, physical conditions like COPD, menopause, and habits like smoking are related to elderly asthma. Proper medications are useful to reduce complications.