Asthma.pdf

Asthma Pathophysiology Review One of the most common lower respiratory disorders that reduces gas exchange is asthma, which can lead to severe lower airway obstruction and death. Asthma is a chronic disease in which reversible acute airway obstruction occurs intermittently, reducing airflow (Fig. 24...

Asthma Pathophysiology Review One of the most common lower respiratory disorders that reduces gas exchange is asthma, which can lead to severe lower airway obstruction and death. Asthma is a chronic disease in which reversible acute airway obstruction occurs intermittently, reducing airflow (Fig. 24.1). Airway obstruction occurs by both inflammation and airway tissue sensitivity (hyperresponsiveness) with bronchoconstriction. Inflammation obstructs the airway lumens (i.e., the hollow insides) (Fig. 24.2). Airway hyperresponsiveness and constriction of bronchial smooth muscle narrow the tubular structure of the airways. Airway inflammation and sensitivity can trigger bronchiolar constriction, and many adults with asthma have both problems (Rogers, 2023). More than 3500 deaths from acute asthma occur in the United States each year (Centers for Disease Control and Prevention [CDC], 2021a). Etiology and Genetic Risk Although asthma may be classified into types based on what triggers the attacks, the effect on gas exchange is the same. Inflammation of the mucous membranes lining the airways is a key event in triggering an asthma attack. Asthma is characterized by chronic airway inflammation, which causes bronchial hyperresponsiveness and airway constriction. Increased airway sensitivity (hyperresponsiveness) can occur with exercise or upper respiratory illness and for unknown reasons. Inflammation associated with asthma can be triggered by different types of white blood cells (WBCs) within the epithelial lining of the lower respiratory tract. For some people, an overabundance of eosinophils makes these airways hyperresponsive, a condition known as eosinophilic asthma. The major mediator that activates eosinophils and increases inflammation leading to asthma attacks is interleukin 5 (IL-5) (Loria, 2021). About 50% of asthma cases are eosinophilic asthma (Shilovskiy et al., 2020) For other people, the WBC type most responsible for the inflammation is the neutrophil, a condition known as neutrophilic asthma. The major mediator that activates neutrophils and increases inflammation leading to asthma attacks is interleukin 17 (IL-17) (Shilovskiy et al., 2020). The symptoms are the same; however, there are some differences in the long-term effects of the disease on the respiratory epithelium. In addition, some drugs are more specific for one type of asthma than the other. FIG. 24.1 Pathophysiology of chronic lower airway problems. Five air chronic airway problems are given as follows: Centriacinar or centrilobular emphysema affects the respiratory bronchioles most severely. It is usually more severe in the upper lung. In emphysema, lung proteases collapse the walls of bronchioles and alveolar air sacs. As these walls collapse, the bronchioles and alveoli transform from a number of small elastic structures with great air-exchanging surface area into fewer, larger, inelastic structures with little surface area. Air is trapped in these distal structures, especially during forced expiration such as coughing, and the lungs hyperinflate. The trapped air stagnates and can no longer supply needed oxygen to the nearby capillaries. Panacinar or panlobular emphysema affects the entire acinar unit. It is usually more severe in the lower lung. In chronic bronchitis, infection or bronchial irritants cause increased secretions, edema, bronchospasm, and impaired mucociliary clearance. Inflammation of the bronchial walls causes them to thicken. This thickening, together with excessive mucus, blocks the airways and hinders gas exchange. In asthma, the airways overreact to common stimuli with bronchospasm, edematous swelling of the mucous membranes, and copious production of thick, tenacious mucus by abundant hypertrophied mucous glands. Airway obstruction is usually intermittent. FIG. 24.2 Causes of narrowed airways. (A) Cross section of a small normal airway with tissue layers. (B) Airway mucosal swelling. (C) Constriction of smooth muscle. (D) Mucosal swelling and constriction of smooth muscle. (E) Mucus plug. Patient-Centered Care: Genetics/Genomics Asthma Development and Treatment Genetic studies have identified more than 100 genes that may play a role in susceptibility, development, and treatment response of asthma (Rogers, 2023). The multiple genetic variants associated with asthma influence the response to treatment and medication management (Barnes, 2023). When asthma is well controlled, airway changes are temporary and reversible. With poor control, chronic inflammation leads to airway damage and altered cellular regulation with enlargement of the bronchial epithelial cells, including mucus-secreting cells, and changes in the bronchial smooth muscle. With frequent asthma attacks, even exposure to low levels of the triggering agent or event may stimulate an attack. Inflammation triggers asthma for some adults when allergens bind to specific antibodies (especially immunoglobulin E [IgE]). These antibodies are attached to tissue mast cells, as well as the WBCs, including basophils, eosinophils, and neutrophils, which are filled with chemicals that can start local inflammatory responses (see Chapters 16 and 17). Some chemicals, such as histamine, start an immediate inflammatory response, which can be blocked by drugs such as diphenhydramine. Others, such as leukotrienes, are slower and cause later, prolonged inflammatory responses, which can be blocked by drugs such as montelukast, zafirlukast, and zileuton. Chemicals also attract more WBCs to the area, which then continue the responses of blood vessel dilation and capillary leak, causing mucous membrane swelling and increased production of mucus (Rogers, 2023). These responses narrow the lumens even more, which then interferes with airflow and gas exchange. Inflammation can also occur through general irritation rather than allergic responses. Bronchospasm is narrowing of the bronchial tubes by constriction of the smooth muscle around and within the bronchial walls. It can occur when small amounts of pollutants or respiratory viruses stimulate nerve fibers, causing constriction of bronchial smooth muscle. If an inflammatory response is stimulated at the same time, the chemicals released during inflammation also trigger constriction. Severe bronchospasm alone, especially in smaller bronchioles, can profoundly limit airflow to the alveoli and greatly reduce gas exchange. Aspirin and other NSAIDs can trigger asthma in some adults, although this response is not a true allergy. It results from increased production of leukotriene when aspirin or NSAIDs suppress other pathways of inflammatory mediator production (American Academy of Allergy Asthma & Immunology [AAAI], 2020). Gastroesophageal reflux disease (GERD) can trigger asthma in some adults and causes asthma symptoms at night (Global Initiative for Asthma [GINA], 2022a). With GERD, highly acidic stomach contents enter the airway and make preexisting tissue sensitivity worse. Incidence and Prevalence Asthma can occur at any age. About half of adults with asthma also had the disease in childhood. Asthma affects over 20 million adults in the United States (Rogers, 2023). Patient-Centered Care: Older Adult Health Airway Changes in Older Adults and Asthma Although often thought of as a disorder that develops most commonly in childhood, asthma also occurs in older adults. Over 4 million adults aged 65 or older have asthma (CDC, 2021a). Lung and airway changes as a part of aging make breathing problems more serious in the older adult, and asthma-related deaths are highest in adults over age 65 years (Touhy & Jett, 2023). Another problem related to aging is a decrease in the sensitivity of beta-adrenergic receptors. When stimulated, these receptors relax smooth muscle and cause bronchodilation. As these receptors become less sensitive, they no longer respond as quickly or as strongly to agonists and beta-adrenergic drugs, which are often used as rescue therapy during an acute asthma attack. Thus teaching older patients how to avoid asthma attacks and how to correctly use preventive drug therapy is a nursing priority. Interprofessional Collaborative Care As a treatable chronic disorder, asthma is generally managed in the community with health care oversight. Acute exacerbations may require management in emergency departments or ICUs. Because asthma is a common disorder, adults admitted to the hospital for other health problems or surgery may also have asthma. For optimal control, continuing the asthma management plan, including drug therapy, is a priority regardless of setting. Recognize Cues: Assessment Asthma is classified on the basis of how well controlled the symptoms are on a consistent basis as defined by the Global Initiative for Asthma (GINA, 2022b). See Box 24.1 for key features of asthma and control levels. History The patient with asthma usually has a pattern of intermittent episodes of dyspnea (perceived shortness of breath), chest tightness, coughing, wheezing, and increased production of mucus. Ask whether the symptoms occur continuously, seasonally, in association with specific activities or exposures, at work, or more frequently at night. Some patients have symptoms for 4 to 8 weeks after a cold or other upper respiratory infection. The patient with atopic (allergic) asthma also may have other allergic problems. Ask whether any family members have asthma or respiratory problems. Ask about current or previous smoking habits. If the patient smokes, use this opportunity to teach about smoking cessation (see Chapter 22). Wheezing in nonsmokers is important in the diagnosis of asthma. Box 24.1 Key FeaturesAsthma Symptoms and Control Level Symptoms Daytime symptoms of wheezing, dyspnea, coughing present more than twice weekly Waking from night sleep with symptoms of wheezing, dyspnea, coughing Reliever (rescue) drug needed more than twice weekly Activity limited or stopped by symptoms Control Level Controlled: None of the above symptoms Partly Controlled: 1 or 2 of the above symptoms Uncontrolled: 3 to 4 of the above symptoms Adapted from Global Initiative for Asthma (GINA). (2022). Pocket guide for asthma management and prevention. https://ginasthma.org/wp-content/uploads/2022/07/GINA-2022-Pocket-Guide-WMS.pdf Physical Assessment/Signs and Symptoms The patient with mild to moderate asthma may have no symptoms between asthma attacks. During an acute episode, common symptoms are an audible wheeze and increased respiratory rate. At first the wheeze is louder on exhalation. When inflammation occurs with asthma, coughing may increase. The patient may use accessory muscles to help breathe during an attack. Observe for muscle retraction at the sternum and the suprasternal notch and between the ribs. The patient with long-standing, severe asthma may have a “barrel chest,” caused by air trapping (Fig. 24.3). The anteroposterior (AP) diameter (diameter between the front and the back of the chest) increases with air trapping, giving the chest a rounded rather than an oval shape. The normal chest is about 1.5 times as wide as it is deep. In severe, chronic asthma, the AP diameter may equal or exceed the lateral diameter (Jarvis & Eckhardt, 2024). Compare the chest AP diameter with the lateral diameter. Chronic air trapping also flattens the diaphragm and increases the space between the ribs. FIG. 24.3 (A) Normal adult. The thorax has an oval shape with an anteroposterior-to-transverse diameter of 1:1.5 or 5:7. (B) Barrel chest. Note equal anteroposterior-to-transverse diameter and that ribs are horizontal instead of the normal downward slope. This is associated with chronic obstructive pulmonary disease and severe asthma as a result of hyperinflation of the lungs. Used with permission from shutterstock.com, Pepermpron. Along with an audible wheeze, the breathing cycle is longer, with prolonged exhalation, and requires more effort. The patient may be unable to speak more than a few words between breaths. Hypoxia occurs with severe attacks. Pulse oximetry shows hypoxemia (poor blood oxygen levels). Examine the oral mucosa and nail beds for cyanosis. Other indicators of hypoxemia include changes in the level of cognition or consciousness and tachycardia. Laboratory Assessment Laboratory tests can determine asthma type and the degree of breathing impairment. Arterial blood gas (ABG) levels show the effectiveness of gas exchange (see Chapter 14 for discussion of ABGs). The arterial oxygen level (PaO2) may decrease during an asthma attack. Early in the attack, the arterial carbon dioxide level (PaCO2) may be decreased as the patient increases the breathing rate and depth. Later in an asthma episode, PaCO2 rises, as does the end-tidal carbon dioxide level, indicating carbon dioxide retention. Allergic asthma often occurs with elevated serum eosinophil counts and immunoglobulin E (IgE) levels. The sputum may contain eosinophils and mucous plugs with shed epithelial cells, known as Curschmann spirals. Pulmonary Function Tests The most accurate tests for measuring airflow in asthma are the pulmonary function tests (PFTs) using spirometry. Baseline PFTs are obtained for all patients diagnosed with asthma. The most important PFTs for a patient with asthma are the forced vital capacity (FVC), the forced expiratory volume in the first second (FEV1), and the peak expiratory flow (PEF), sometimes called peak expiratory rate flow (PERF). Definitions of PFTs are listed in Chapter 22. Diagnosis is made based on the variations and the frequency of variation of airflow limitations (GINA, 2022b). Asthma is diagnosed when these values increase by 12% or more after treatment with bronchodilators. Airway responsiveness is tested by measuring the PEF and FEV1 before and after the patient inhales the drug methacholine, which induces bronchospasm in susceptible adults. Take Actions: Interventions The purposes of asthma therapy are to control and prevent episodes, improve airflow and gas exchange, and relieve symptoms. Asthma is best controlled when the patient is an active partner in the management plan. Priority nursing actions focus on patient education about using a personal asthma action plan, which includes drug therapy and lifestyle management strategies to help patients understand the disease and its management (GINA, 2022b). Self-Management Education Asthma often has intermittent overt symptoms. With guided self-care, patients can co-manage this disease, increasing symptom-free periods and decreasing the number and severity of attacks. Good management decreases hospital admissions and increases participation in patient-chosen work and leisure activities. Self-care requires extensive education for the patient to be able to monitor respiratory status, recognize symptoms, and manage and adjust medications based on symptoms; self-care also includes the knowledge of when to consult the health care provider or seek emergency care (Asthma and Allergy Foundation of America [AAFA], 2021). Ideally, a personal asthma action plan is developed by the primary health care provider and the patient. The plan is tailored to meet the patient’s personal triggers, asthma symptoms, and drug responses. It includes: The prescribed daily controller drug(s) schedule and prescribed reliever drug directions Patient-specific daily asthma control assessment questions Directions for adjusting the daily controller drug schedule When to contact the primary health care provider (in addition to regularly scheduled visits) Emergency actions to take when asthma is not responding to controller and reliever drugs Keeping track of symptoms and actions is necessary, and peak flow monitoring is useful. Patients should also be instructed to self-monitor peak flow measurements when experiencing an exacerbation, after a change in treatment, when measuring a response to treatment, or when symptoms appear to be more severe or excessive (GINA, 2022b). Teach the patient to keep a symptom and intervention diary to learn specific triggers of asthma, early cues for impending attacks, and personal response to drugs. Stress the importance of proper use of the personal asthma action plan for any severity of asthma, as described in Box 24.2. Drug Therapy Pharmacologic management of adults with asthma is based on the step category for severity and treatment as outlined in the Box 24.2 (GINA, 2022b). Control therapy drugs are used to reduce airway sensitivity (responsiveness) to prevent asthma attacks from occurring and maintain gas exchange. They are used every day, regardless of symptoms. Reliever drugs (also called rescue drugs) are used to actually stop an attack once it has started. Short-acting beta2-agonists (SABA) may be used as reliever inhalers, and research suggests the inhaled corticosteroid (ICS) formoterol may also be used as a reliever inhaler in the treatment of asthma in adults (GINA, 2022b). Some patients may need drug therapy only during an asthma episode. For others, daily drugs are needed to keep asthma episodic rather than a more frequent problem. Therapy involves the use of bronchodilators and various drug types to reduce or prevent inflammation. Combination drugs are two or more agents from different classes combined together for better response. Box 24.2 Patient and Family EducationAsthma Management Avoid potential environmental asthma triggers, such as smoke, fireplaces, dust, mold, and weather changes of warm to cold. Avoid drugs that trigger your asthma (e.g., aspirin, NSAIDs, beta blockers). Avoid food that has been prepared with monosodium glutamate (MSG) or metabisulfite. If you have exercise-induced asthma, use your reliever bronchodilator inhaler 30 minutes before exercise to prevent or reduce bronchospasm.  Be sure that you know the proper technique and correct sequence when you use metered dose inhalers. Get adequate rest and sleep. Reduce stress and anxiety; learn relaxation techniques; adopt coping mechanisms that have worked for you in the past. Wash all bedding with hot water to destroy dust mites. Seek immediate emergency care if you experience any of these: Gray or blue fingertips or lips Difficulty breathing, walking, or talking Retractions of the neck, chest, or ribs Nasal flaring Failure of drugs to control worsening symptoms Data adapted from Global Initiative for Asthma (GINA). (2022). Pocket guide for asthma management and prevention. https://ginasthma.org/wp-content/uploads/2022/07/GINA-2022-Pocket-Guide-WMS.pdf With step therapy (Box 24.3), drug therapy is prescribed at different levels, starting with step 1 and progressing up (stepping up) until acceptable control is achieved. When the patient achieves control and maintains it for 3 months, the respiratory health care provider adjusts the drug regimen down (stepping down) a step at a time to reach and maintain a goal of good control at the lowest possible drug dosages. Table 24.1 lists the most common and preferred drugs in each class for control and relief therapy of asthma. The actions and interventions for most drugs within a single class are similar. Be sure to consult a drug handbook, electronic drug reference, or pharmacist for information on a specific drug. Many of the drugs used for asthma control and relief are delivered using inhalers. Currently three types of inhalers are available: metered dose inhalers (MDIs), which deliver drugs as a fine liquid spray; dry powder inhalers (DPIs), which deliver drugs as a fine powder; and soft mist inhalers (SMIs). The MDIs require a propellant to form an aerosol spray and may be used with a spacer (preferred) or without a spacer. DPIs rely on the negative pressure of inhalation to pull the drug into the respiratory tract. SMIs have a mechanical spring-loaded device that creates an aerosol cloud or mist, which is then pulled into the respiratory tract by patient inhalation. Neither DPIs nor SMIs use a spacer for drug delivery. An advantage of SMIs over MDIs and DPIs is that the small size and weight of particles ensure that less drug falls out in the mist and more reaches the lower airways (Burchum & Rosenthal, 2022). Many patients do not get the full benefit of inhaled drugs because of incorrect device use. Often the inhaled drug stays in the mouth and throat or exits through the nose without ever reaching the lower airways. Improper use of inhalers leads to reduced effects of the medication (Hatefi et al., 2021). See Box 24.4 for general teaching related to inhalers. Teaching the proper use of an inhaler can be done in person or with technology (Volerman et al., 2021). Online videos, for example, can be useful for patient education. Videos can demonstrate the use, care, and cleaning of inhalers. Most prescribed inhalers now have meters that indicate the number of doses left in the canister so that patients will know when to have the prescription refilled and not miss doses. Box 24.3 Best Practice for Patient Safety and Quality CareThe Step System for Medication Use in Asthma Control Step 1 Step 2 Step 3 Step 4 Step 5 As-needed short-acting beta2-agonist (SABA) (relief inhaler) As-needed SABA (relief inhaler), daily LTRA, and sublingual allergen immunotherapy (SLIT) As-needed SABA (relief inhaler), maintenance and reliever (ICS)-formoterol, possible daily LTRA or low-dose sustained-release theophylline, and SLIT As-needed SABA (relief inhaler) and maintenance medium-dose (ICS)-formoterol; consider adding LAMA and SLIT As-needed SABA (relief inhaler); refer for assessment, phenotyping, and add-on therapy (which may include daily LAMA, anti-IgE, interleukin-5 antagonist, interleukin-4 antagonist, or consider high-dose ICS-formoterol, azithromycin [adults] or daily LTRA, or low-dose oral corticosteroids) Alternate treatment options for adults and adolescents: low-dose ICS-formoterol as a reliever Alternate treatment options for adults and adolescents: low-dose ICS in combination or as separate inhalers with SABA, regular daily combination LABA Alternate treatment options for adults and adolescents: maintenance ICS-LABA plus as-needed SABA Alternate treatment options for adults and adolescents: maintenance medium-dose ICS-LABA with as-needed SABA ICS, Inhaled corticosteroid; IgE, immunoglobulin E; LABA, long-acting beta2-agonist; LAMA, long-acting muscarinic antagonist; LTRA, leukotriene receptor antagonist. Table 24.1 Common Examples of Drug Therapy Asthma Prevention and Treatment Drug CategorySelected Nursing Implications Bronchodilators Induce rapid bronchodilation through relaxing bronchiolar smooth muscle by binding to and activating pulmonary beta2 receptors. Short-Acting Beta2-Agonist (SABA) Primarily used as a fast-acting reliever (rescue) drug to be used either during an asthma attack or just before engaging in activity that usually triggers an attack. Albuterol (inhaled drug) Levalbuterol (inhaled drug) Teach patients to carry drug with them at all times because it can stop or reduce life-threatening bronchoconstriction. Teach patient to monitor heart rate because excessive use causes tachycardia and other systemic symptoms. When taking any of these drugs with other inhaled drugs, teach patient to use them at least 5 minutes before the other inhaled drugs to allow the bronchodilation effect to increase the penetration of other inhaled drugs. Long-Acting Beta2-Agonist (LABA) Causes bronchodilation through relaxing bronchiolar smooth muscle by binding to and activating pulmonary beta2 receptors. Onset of action is slow with a long duration. The primary use is prevention of an asthma attack. Salmeterol (inhaled drug) Indacaterol (COPD only) (inhaled drug) Formoterol (COPD only) (inhaled drug) Arformoterol (COPD only) (inhaled drug) Teach patient not to use these drugs as reliever drugs because they have a slow onset of action and do not relieve acute symptoms. Cholinergic Antagonist Causes bronchodilation by inhibiting the parasympathetic nervous system, allowing the sympathetic system to dominate, releasing norepinephrine that activates beta2 receptors. The purpose is to prevent asthma attacks or COPD bronchospasms and improve gas exchange, although some are considered reliever drugs. Aclidinium (inhaled drug for prevention only) Ipratropium (inhaled drug for relief and prevention) Tiotropium (inhaled drug) Umeclidinium (inhaled drug for prevention only) If patient is to use any of these as a reliever drug, teach them to carry it at all times because it can stop or reduce life-threatening bronchoconstriction. For drugs delivered by MDI, teach patient to shake the inhaler well before using because the drugs separate easily. Teach patient to increase daily fluid intake because the drugs cause mouth dryness. Teach patient to observe for and report blurred vision, eye pain, headache, nausea, palpitations, tremors, and inability to sleep as these are systemic symptoms of overdose and require intervention. Table Continued Drug CategorySelected Nursing Implications Antiinflammatories All of these drugs help improve bronchiolar airflow and increase gas exchange by decreasing the inflammatory response of the mucous membranes in the airways. They do not cause bronchodilation. Corticosteroids Disrupt production pathways of inflammatory mediators. The main purpose is to prevent an asthma attack caused by inflammation or allergies (controller drug). Fluticasone (MDI inhaled drug) Beclomethasone (MDI inhaled drug) Budesonide (MDI inhaled drug) Teach patient to use the drug daily, even when no symptoms are present, because maximum effectiveness requires continued use for 48 to 72 hours and depends on regular use. Teach patient to use good mouth care and to check mouth daily for lesions or drainage because these drugs reduce local immunity and increase the risk for local infections, especially Candida albicans (yeast). Teach patient not to use these drugs as reliever drugs because they have a slow onset of action and do not relieve acute symptoms. Prednisone (oral drug) Teach patient about expected side effects because knowing which side effects to expect may reduce anxiety when they appear. Teach patient to avoid anyone who has an upper respiratory infection because the drug reduces all protective inflammatory responses, increasing the risk for infection. Teach patient to avoid activities that lead to injury because blood vessels become more fragile, leading to bruising and petechiae. Teach patient to take the drug with food to help reduce the side effect of GI ulceration. Teach patient not to suddenly stop taking the drug for any reason because the drug suppresses adrenal production of corticosteroids, which are essential for life. Cromolyn Stabilizes the membranes of mast cells and prevents the release of inflammatory mediators. The purpose is to prevent asthma attack triggered by inflammation or allergens. Nedocromil (inhaled drug) Teach patient to use the drug daily, even when no symptoms are present, because maximum effectiveness requires continued use for 48 to 72 hours and depends on regular use. Teach patient meticulous inhaler maintenance. Teach patient to not use this drug as a reliever drug because it has a slow onset of action and does not relieve acute symptoms. Leukotriene Modifier Blocks the leukotriene receptor, preventing the inflammatory mediator from stimulating inflammation. The purpose is to prevent asthma attack triggered by inflammation or allergens. Montelukast (oral drug) Monitor for mental health changes, including suicidal thoughts or actions as this drug has a boxed warning regarding the risk of mental health side effects. Teach patient to use the drug daily, even when no symptoms are present, because maximum effectiveness requires continued use for 48 to 72 hours and depends on regular use. Teach patient not to decrease the dose of or stop taking any other asthma drugs unless instructed by the health care professional because this drug is for long-term asthma control and does not replace other drugs, especially corticosteroids and reliever (rescue) drugs. Monoclonal Antibodies Bind to and block the actions of proinflammatory cytokines (interleukin 5) or cell surface sites of IgE that trigger and maintain asthma attacks. Interleukin antagonists: Benralizumab (subcutaneous injection) Mepolizumab (subcutaneous injection) Reslizumab (slow IV infusion only) Only for use in patients who have eosinophilic asthma because these drugs block the actions of interleukin-5 (IL-5), which activates eosinophils and increases their numbers. Do not administer these drugs as a reliever drug because they do not relieve acute symptoms. Monitor patient for at least 2 hours after injection for indications of severe hypersensitivity and anaphylaxis because these drugs contain a foreign protein that has an increased risk for severe allergic reactions. IgE antagonist: Omalizumab (subcutaneous injection) Used only for patients who have a known allergy that triggers asthma attacks because the drug works by antagonizing IgE. Monitor patient for at least 2 hours after injection for indications of severe hypersensitivity and anaphylaxis because the drug contains a foreign protein that has an increased risk for severe allergic reactions. Do not administer this drug as a reliever drug because it does not relieve acute symptoms. DPI, Dry powder inhaler; MDI, metered dose inhaler. Data from Global Initiative for Asthma (GINA), (2022). Pocket guide for asthma management and prevention, https://ginasthma.org/wp-content/uploads/2022/07/GINA-2022-Pocket-Guide-WMS.pdf; and Burchum, J., & Rosenthal, L. (2022). Lehne’s Pharmacology for nursing care (11th ed.). St. Louis: Elsevier. Box 24.4 Patient and Family EducationInhaler Use a Inhaler Type Selected Education Metered dose inhalers (MDIs) Shake the canister for 5 seconds between each inhalation. Inhale through your mouth (not your nose) when breathing in the medication. Place your tongue under the inhaler mouthpiece so that it does not block the medication. Inhale slowly and deeply when you press down on the medication canister. Hold your breath for 5–10 seconds after inhalation of the medication and then exhale. Spacer devices can be used if you have difficulty timing the spray of the medication with inhalation. Dry powder inhalers (DPIs) Breathe out slowly and completely. (Do not breathe into the mouthpiece.) Place the mouthpiece between your front teeth; seal your lips around the mouthpiece. Inhale through your mouth quickly and deeply over 2–3 seconds. Hold your breath for 4–10 seconds (as long as you can comfortably). Breathe out slowly. Do not wash the DPI with water. Soft mist inhalers (SMIs) Must be primed before the first use. To prime, open the cap and point the inhaler toward the floor (away from your face) and press the button on the side until you see a mist. Repeat this cycle three times. If it has been more than 3 days since your last use of the SMI, complete one priming cycle. Put the mouthpiece in your mouth and aim the inhaler toward the back of your throat. Close your lips around the mouthpiece. Do not cover the air vents on the side. Inhale slowly and deeply and press the button on the side of the inhaler. Hold your breath for 10 seconds to keep the medicine in your lungs. Breathe out slowly. a Each manufacturer has specific recommendations. Be sure to review the manufacturer guidelines. These are general education principles associated with the overall type of inhaler. Data from Gerald, L., & Dhand, R. (2023). Patient education: Inhaler techniques in adults (Beyond the basics). UpToDate. Retrieved March 25, 2023, from https://www.uptodate.com/contents/inhaler-techniques-in-adults-beyond-the-basics. Bronchodilators Bronchodilators cause bronchiolar smooth muscle relaxation but have no effect on inflammation. Thus for patients who have airflow obstruction by both bronchospasm and inflammation, at least two types of drug therapy are needed. Bronchodilators include beta2-agonists and cholinergic antagonists. Beta2-agonists bind to and stimulate the beta2-adrenergic receptors in the same way that epinephrine and norepinephrine do. This causes an increase in smooth muscle relaxation. Short-acting beta2-agonists (SABAs) provide rapid but short-term relief. These inhaled drugs are most useful when an attack begins (as relief) or as premedication when the patient is about to begin an activity that is likely to induce an attack (Burchum & Rosenthal, 2022). Such agents include albuterol, levalbuterol, and terbutaline. Nursing Safety Priority Action Alert Teach the patient with asthma to always carry the relief drug inhaler and to ensure that enough drug remains in the inhaler to provide a quick dose when needed. Long-acting beta2-agonists (LABAs) are also delivered by inhaler directly to the site of action—the bronchioles. Proper use of the long-acting agonists decreases the need to use reliever drugs as often. Unlike short-acting agonists, long-acting drugs need time to build up an effect, but the effects are longer lasting. These drugs are useful in preventing an asthma attack but cannot stop an acute attack. Therefore, teach patients not to use LABAs alone to relieve symptoms of an attack or when wheezing is getting worse but, instead, to use a SABA. Examples of LABAs include formoterol and salmeterol. Both drugs are associated with increased asthma deaths when used as the only therapy for asthma and carry a black box warning from the U.S. Food and Drug Administration (FDA). Nursing Safety Priority Drug Alert LABAs should never be prescribed as the only drug therapy for asthma and are not to be used during an acute asthma attack or bronchospasm. Teach the patient to use these control drugs daily as prescribed, even when no symptoms are present, and to use a SABA to relieve acute symptoms. Any patient using these drugs must be monitored closely. Cholinergic antagonists, also called anticholinergic drugs or long-acting muscarinic antagonists (LAMAs), are similar to atropine and block the parasympathetic nervous system. This action increases bronchodilation and decreases pulmonary secretions. The most common drug in this class is ipratropium inhalant. Some cholinergic antagonists are short acting and are used several times a day. Long-acting agents such as tiotropium are used once daily. Methylxanthines such as theophylline and aminophylline are used rarely, only when all other types of management are ineffective. These drugs are given systemically, and the dosage that is effective is close to the dosage that produces many dangerous side effects. Blood levels must be monitored closely to ensure that the drug level is within the therapeutic range. Antiinflammatory Agents Antiinflammatory agents decrease airway inflammation. The inhaled forms have fewer systemic side effects than those taken systemically. All antiinflammatory drugs, whether inhaled or taken orally, are controller drugs only. Nursing Safety Priority Drug Alert Antiinflammatory drug therapy for asthma is for prevention or control of asthma. These drugs are not effective in reversing symptoms during an asthma attack and should not be used alone as reliever drugs. Teach patients to take antiinflammatory asthma drugs on a scheduled basis, even when no symptoms are present. Corticosteroids decrease inflammation in many ways, including by reducing the production of inflammatory chemicals. Inhaled corticosteroids (ICS) are the most effective antiinflammatory medication for asthma (GINA, 2022b). High-potency steroid inhalers, such as fluticasone, budesonide, and mometasone, may be used once per day for maintenance. Some drugs for asthma control include those that are combinations of an inhaled corticosteroid and an inhaled beta2-agonist, such as Breo Elipta. This combination comes in different strengths and is used once daily. Systemic corticosteroids, because of severe side effects, are avoided for mild to moderate intermittent asthma and are used on a short-term basis for moderate asthma. For some patients with severe asthma, daily oral corticosteroids may be needed. Cromolyns, inhalation agents, are useful as controller asthma therapy when taken on a scheduled basis. These agents reduce airway inflammation by either inhibiting the release of inflammatory chemicals (nedocromil) or preventing mast cell membranes from opening when an allergen binds to IgE (cromolyn sodium). Leukotriene modifiers are oral drugs that work in several ways to control asthma when taken on a scheduled basis. Montelukast and zafirlukast block the leukotriene receptor. Zileuton prevents leukotriene synthesis. Monoclonal antibodies are newer drugs specifically for the management of airway inflammation. Categories of monoclonal antibodies include IgE antibody antagonists (omalizumab), interleukin-4 receptor antagonists (dupilumab), and interleukin-5 receptor antagonists (benralizumab, mepolizumab, and reslizumab). None of these medications are first-line agents to manage acute asthmatic episodes (Burchum & Rosenthal, 2022). Exercise and Activity Regular exercise is a recommended part of asthma therapy to maintain cardiac health, strengthen muscles, and promote gas exchange and perfusion. Teach patients to examine the conditions that trigger an attack and adjust the exercise routine as needed. Some may need to use an inhaled SABA before beginning activity. For others, adjusting the environment may be needed (e.g., changing from outdoor ice-skating in cold, dry air to indoor ice-skating). Oxygen Therapy Supplemental oxygen by mask or nasal cannula is often used during an acute asthma attack. High-flow delivery may be needed when bronchospasms are severe and limit flow of oxygen through the bronchiole tubes. Nursing Safety Priority Action Alert Ensure that no open flames (e.g., smoking, fireplaces, burning candles) or other combustion hazards are in rooms where oxygen is in use. Status Asthmaticus Status asthmaticus is a severe, life-threatening acute episode of airway obstruction that intensifies once it begins and often does not respond to usual therapy. The patient arrives in the emergency department with extremely labored breathing and wheezing. The use of accessory muscles for breathing and the distention of neck veins are observed. If the condition is not reversed, the patient may develop pneumothorax and cardiac or respiratory arrest. IV fluids, potent systemic bronchodilators, steroids, epinephrine, and oxygen are given immediately to reverse the condition. Prepare for emergency intubation. Sudden absence of wheezing along with a low oxygen saturation indicates complete airway obstruction and requires a tracheotomy. When breathing improves, management is similar to that for any patient with asthma. NCLEX Examination Challenge 24.1 Safe and Effective Care Environment The nurse is teaching a client who is newly diagnosed with asthma. Which information would the nurse include in the teaching? A. Use the inhaled corticosteroid when experiencing dyspnea. B. Bronchodilators are rapid acting, and side effects include tremors. C. Immediately after using the inhaler, breathe out slowly. D. When using a dry powder inhaler, inhale slowly.