Learning Objectives
By the end of this section, you will be able to:
- Discuss the pathophysiology, risk factors, and clinical manifestations for asthma
- Describe the diagnostics and laboratory values in the disease of asthma
- Apply nursing concepts and plan associated nursing care for the patient with asthma
- Evaluate the efficacy of nursing care for the patient with asthma
- Describe the medical therapies that apply to the care of asthma
Asthma is one of the most prevalent conditions in the United States. Nationwide, about one in every thirteen people has asthma. About 4.8 million children and about 21 million adults have asthma. In children, asthma is more common in males. In adults, asthma is more common in females.
Pathophysiology
Asthma primarily affects the trachea and bronchi. Normally, lungs can easily expand and contract with inspiration and expiration. In asthma, inflammation narrows the airway, making it harder for the lungs to expand, causing an asthma attack (Figure 11.14). An asthma attack is also known as asthma exacerbation. Asthma exacerbations have an early phase and a late phase. In the early phase, triggers, such as exercise, cold air, hormonal fluctuations, allergens, and fumes, cause antibodies to be released. These antibodies bind to mast cells and basophils within the lining of the respiratory tract. Mast cells release leukotrienes, histamine, and prostaglandins. These substances cause bronchoconstriction, meaning the smooth muscle in the airways constrict, narrowing the airway.
In the late phase, white blood cells, including basophils, eosinophils, neutrophils, and helper and memory T-cells, flow to the lungs. Inflammation, further bronchoconstriction, and increased mucous production occur. Airflow becomes obstructed because of inflammation and airway constriction, causing increased respiratory effort. In a patient with asthma, the airways are considered hyperresponsive, indicating they narrow more than usual in response to stimuli (Sinyor & Perez, 2022).
Link to Learning
Watch this video about asthma pathophysiology to learn more.
Risk Factors
In the United States, 13.5 percent of people have been diagnosed with asthma, and females have a 12 percent higher prevalence of an asthma diagnosis than males (American Lung Association, 2024). Additional risk factors for developing asthma include a family history, prematurity, maternal smoking during pregnancy, and obesity. Many factors both increase the risk of asthma and can trigger an asthma attack. These include allergies, allergic conditions like eczema, viral respiratory infections, cigarette smoking, air pollution, and exposure to substances including dust, fumes, mold, and vapor (Morales et al., 2021).
There are significant racial and ethnic disparities that affect how likely a person is to experience exacerbations, illness, and death related to asthma. Structural factors include systemic racism, lack of access to adequate care, economic disparities, and the physical environment. These factors create inequitable risk that disproportionately affect patients with fewer financial resources, older adults, and Black, Hispanic, and American Indian/Alaska Native populations. Black Americans are nearly three times more likely than White Americans to die from asthma. Overall, Black females have the highest risk of death related to asthma. Compared with White men, Black women have more than triple the risk of dying of asthma. In 2021, 3,517 people died due to asthma. Notably, nearly all asthma deaths are preventable when there is access to adequate resources (Asthma and Allergy Foundation of America, 2023).
Clinical Manifestations
Asthma has four defined stages based on severity: intermittent, mild, moderate, and severe (Table 11.2). Regardless of stage, patients with asthma usually report difficulty breathing, wheezing, and a cough. Often, the cough is worse at night. Symptoms are commonly in response to a trigger, such as exercise or allergens. In severe exacerbations, respiratory rate and heart rate increase, and patients may sit upright to lean forward into tripod position to facilitate easier breathing.
| Stage of Asthma | Symptom Frequency | Nighttime Awakenings Due to Symptoms |
|---|---|---|
| Intermittent | < 2 days per week | < 2 times per month |
| Mild | > 2 days a week but not daily | 3 to 4 times a month |
| Moderate | Daily | > than once a week but not nightly |
| Severe | Daily + throughout the day | Often > 7 times per week |
Assessment and Diagnostics
Asthma symptoms may shift over time. Accurate assessment is crucial during initial diagnosis and to prevent complications. Diagnostic tests can provide information about disease severity.
Asthma is diagnosed based on patient history combined with pulmonary function testing. History includes at least one or two, though sometimes all, of the following symptoms in response to a trigger (e.g., allergen, cold air, exercise, infection):
- shortness of breath
- cough that is often worse at night
- wheezing
- chest tightness
Because these symptoms can occur with many respiratory illnesses, additional information is necessary to diagnose asthma. Asthma symptoms typically wax and wane over a period of hours to days and commonly occur in response to a trigger, such as cold air or exercise. Asthma is more common in patients with a family history of asthma and allergies. A person’s personal history of asthma-like symptoms as a child, with or without a formal diagnosis of asthma, increases the likelihood of an asthma diagnosis as an adult. Patients with asthma also often exhibit other inflammatory conditions, such as eczema.
The gold standard of an asthma diagnosis is pulmonary function testing. These tests provide precise information about how air flows into and out of the body. Moreover, spirometry testing (Table 11.3) measures:
- Forced vital capacity (FVC): the maximum volume of air that can be forcibly exhaled after fully inhaling
- Forced expiratory volume (FEV1): the amount of that can be forcefully exhaled in one second
These measurements demonstrate specific patterns in asthma, assess the level of airflow obstruction, and provide information about disease severity. Spirometry tests are also used to assess airway changes in response to bronchodilator administration; bronchodilators open narrowed airways and allow a significant increase in the volume of air that can be inhaled and forcefully exhaled.
| Spirometry Testing | What It Measures or Identifies |
|---|---|
| Forced vital capacity (FVC) | The maximum volume of air that can be forcibly exhaled after fully inhaling |
| Forced expiratory volume (FEV1) | The amount of that can be forcefully exhaled in one second Expressed as a percent of predicted value Obstruction is defined as less than 0.8 (80 percent) |
| FEV1/FVC ratio | Can identify if there is baseline airflow obstruction A reduced ratio indicates obstruction Obstruction is defined as less than 0.7 |
Exhaled nitric oxide measurement can be used to support an asthma diagnosis, though it is not considered conclusive. In some patients with asthma, airway inflammation leads to increased levels of nitric oxide during exhalation. Similarly, complete blood count test results can be used to support an asthma diagnosis. Elevated eosinophil levels can be present in allergic asthma (Fanta & Lange-Vaidya, 2022).
Nursing Care of the Patient with Asthma
While asthma is a treatable condition, there is the potential for serious complications and even death. Careful monitoring, robust patient education, and timely intervention are key interventions to optimize outcomes. Asthma diagnosis can range from intermittent, to persistent, allergy and exercise induced, pediatric and adult-onset, as well as overlap with other respiratory diseases like chronic obstructive pulmonary disease (COPD).
Recognizing Cues and Analyzing Cues
The nurse providing care to a patient with asthma utilizes both objective and patient-reported data to optimize care. Subjective data can include the presence of shortness of breath, wheezing, chest tightness, cough, increased mucus, activity limitations, and frequency of nighttime waking due to breathing difficulty. Vital signs are evaluated with a focus on respiratory rate and oxygen saturation. In periods of labored breathing, tachycardia may be present. The nurse performs auscultation, noting the location and character of any abnormal lung sounds. Expiratory wheezes are the most common adventitious lung sound in asthma. If the patient has a cough, the nurse asks about the frequency and characteristics; a nighttime cough is common with asthma.
Environmental irritants can trigger asthma exacerbations; ask the patient about exposure to allergens, secondhand smoke, and vapors. If the patient smokes or vapes, inquire about frequency and duration. Preventable respiratory illnesses can cause serious illness. Discuss immunization status and recommended vaccines as clinically appropriate. Patients may have to mask if they are susceptible to illness and in congested public areas.
Prioritizing Hypotheses, Generating Solutions, and Taking Action
Signs of respiratory distress and inadequate oxygenation are a high priority. The nurse may assist with spirometry testing and review results and administer medications such as bronchodilators and glucocorticoids. Patient education topics include using an inhaler and peak flow meter, strategies to avoid triggers, and implementing an asthma action plan (Figure 11.15, Figure 11.16, and Figure 11.17). An asthma action plan gives a patient detailed information about how to monitor symptoms and adjust medications when needed to prevent severe exacerbations.
Steroid inhalers can increase the risk of oral candida infections, so patient education should include rinsing the mouth after use, and use of spacers if indicated. In acute exacerbations, nursing interventions may include monitoring oxygen saturation and applying supplemental oxygen. The nurse collaborates with respiratory therapy and the provider to identify SpO2 targets and optimize oxygenation.
Link to Learning
The Asthma and Allergy Foundation of America has resources for patients and families. This video provides important teaching points about how to use inhalers, nebulizers, spacers, and chambers.
Evaluation of Nursing Care for the Patient with Asthma
Evaluating nursing care for patients with asthma centers around symptom assessment and management. Accurately understanding the patient’s experience of symptoms improves the nurse’s ability to evaluate outcomes.
The primary patient outcome related to asthma management is symptom frequency. The nurse evaluates how often the patient experiences symptoms, including how often the patient is awakened from sleep due to difficulty breathing. It is important to understand how often the patient experiences respiratory distress severe enough to warrant using rescue medications. Lung function can be evaluated using spirometry. In acute exacerbations, monitor oxygen saturation and requirements.
Medical Therapies and Related Care
Asthma treatment focuses on controlling current asthma symptoms and decreasing future complications. Collaborative care for patient and caregiver education is a key component of asthma care. The interprofessional team includes providers, nurses, respiratory therapists, and pharmacists. Patient education topics include medication administration, home monitoring, and strategies to prevent exacerbation. Patient education strategies may include videos, teaching materials, and hands-on demonstration. A personalized, written asthma action plan can help caregivers and patients stay safe. These can include contact information for clinical team members, a medication list with instructions, clear information on how to manage flares, and when to seek help or call 911. A home peak flow meter (Figure 11.18) allows patients to track and observe trends in their lung function.
Identifying triggers and controlling exposure is important for patients with asthma. Some triggers (e.g., exercise, significant emotions, hormonal fluctuations, respiratory illnesses) cannot be avoided. In those cases, awareness of their personal response to various triggers can help patients to anticipate and manage symptoms.
During times when an asthma patient is experiencing acute shortness of breath, short-acting beta-agonists (SABAs) are bronchodilators used to decrease bronchoconstriction. These are considered “rescue” medications because they start working within fifteen to thirty minutes. Medications in this class include albuterol and levalbuterol. In severe flares, oral or intravenous corticosteroids are often necessary to decrease inflammation. Medications used to treat asthma are summarized in Table 11.4.
| Medication Class | Example | Additional Information |
|---|---|---|
| Short-acting beta-agonist (SABA) | Albuterol Levalbuterol |
Inhaled or nebulized Onset of action: 15 to 30 minutes Considered “rescue” medications |
| Long-acting beta-agonist (LABA) | Salmeterol Formoterol |
Oral, inhaled, or nebulized |
| Inhaled corticosteroids | Budesonide Fluticasone propionate |
In severe flares, oral or IV corticosteroids are used. |
| Leukotriene inhibitors | Montelukast | Oral Can prevent asthma symptoms and treat allergy symptoms |
| Long-acting muscarinic antagonist (LAMA) | Tiotropium | Used in moderate cases Dry powder or mist inhaler |
| Mast cell stabilizers | Cromolyn | Can be used to treat allergic responses and prevent exercise-induced symptoms Rarely used due to more effective treatment options |
| Methylxanthine | Theophylline | Used to treat bronchoconstriction Rarely used due to more effective treatment options |
Long-term medication management focuses on reducing chronic inflammation. These medications can include long-acting beta-agonists (LABAs), like salmeterol or formoterol, inhaled corticosteroids, and leukotriene inhibitors, like montelukast. Some inhalers combine corticosteroid with a LABA. Inhaled long-acting muscarinic antagonists (LAMAs), like tiotropium, are used in moderate cases. Additionally, mast cell stabilizers, such as cromolyn, can be used to treat allergic responses and prevent exercise-induced symptoms. Theophylline is a methylxanthine that is sometimes used to treat bronchoconstriction.