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• Lower Respiratory Disorders cover diseases like asthma, emphysema, chronic bronchitis, pneumonia, and tuberculosis.

Respiratory System Review

• The main function is not stated.
• This is accomplished via ventilation, diffusion, and perfusion.
• Conducting Airways Composition is an important factor to consider
• Alveoli destruction is irreversible
• There are Type I and Type II Alveolar cells
• Pulmonary circulation facilitates gas exchange
• Neurochemical control includes the respiratory center and chemoreceptors for CO2 & O2.
• Mechanics of breathing involve major & accessory muscles, lung elasticity, airway resistance, alveolar surface tension, and work of breathing.
• Gas transport involves O2 & CO2 transport and the distribution of ventilation.
• Control of pulmonary circulation involves distributing pulmonary blood flow.

Asthma Pathophysiology

• Shortness of breath is recurrent and reversible

• Cascade occurs following exposure to an allergen

• Sensitization to an allergen occurs through initial exposure.

• T cells stimulate B cells (memory cells).

• B cells develop into plasma cells.

• Plasma cells produce IgE antibodies, that target that specific allergen

• IgE binds to receptors on mast cells.

• The early phase response occurs upon re-exposure to an allergen.

• IgE of mast cells binds to the allergen and cross-links, releasing histamine, prostaglandins, and leukotrienes

• These immune mediators cause bronchoconstriction, vasodilation, and increased capillary permeability.

• The late phase response to an allergen begins at the same time as the early phase response.

• Worsening symptoms appear 3-10 hours later and last for 24 hours, possibly involving eosinophils

• The inflammatory and remodeling responses in asthma with activation of the epithelial mesenchymal trophic unit are shown in a diagram

Pathophysiology of Asthma

• Airflow obstruction is related to contraction of airway smooth muscle, thickening of airway wall from cellular edema and plugging of the airways with mucus and debris

• Obstruction in large airways leads to air flow limitation and decreased flow rates

• Obstruction in small airways leads to airway closure and air-trapping/hyperinflation

• Alveolar ducts/alveoli remain open, but airflow to them is obstructed

• Factors causing obstruction include smooth muscle contraction, swollen mucosa, and mucus plugs which cause the bronchioles to narrow.

Asthma Types

• Asthma can be intrinsic or extrinsic
• Extrinsic asthma triggers include allergens and air pollutants
• Triggers of occupational forms include drug and food additives
• Other forms of asthma induced by exercise and respiratory infections
• Potential causes include nasal/sinus problems

Clinical Manifestations of Asthma

• Episodes are unpredictable and variable
• Recurrent episodes include wheezing, breathlessness, cough, and tight chest
• These episodes may be abrupt or gradual
• Episodes can last from minutes to hours
• Expiration may be prolonged resulting in a shortened breath
• Inspiration-expiration ratio changes from 1:2 to 1:3 or 1:4
• Air takes longer to move out
• Wheezing is unreliable to gauge severity
• A severe attack may have no audible wheezing, and usually begins upon exhalation
• Difficulty with air movement can create a feeling of suffocation.
• Patients may feel increasingly anxious
• An acute attack usually reveals signs of hypoxemia: restlessness, anxiety, inappropriate behavior, increased pulse, and blood pressure.
• Status asthmaticus is a prolonged asthma attack that does not respond to typical drug therapy which may last several minutes to hours and is a medical emergency requiring intubation and mechanical ventilation.

Chronic Bronchitis

• Defined as a chronic productive cough for three months in each of two successive years in a patient whom other causes of chronic cough have been excluded which causes permanent structural damage
• Continuous inflammation of the bronchi and bronchioles
• Often occurs as a result of prolonged exposure to bronchial irritants/toxics (e.g., smoking)
• An increase in the number of goblet cells with damaged cilia that leads to mucus production

Emphysema

• Defined as abnormal and permanent enlargement of the airspaces distal to the terminal bronchioles that is accompanied by destruction of the airspace walls.
• Air spaces enlarge from alveolar wall destruction
• The surface area where gas exchange takes place is reduced
• Effective respiration is impaired often as a result of air trapping

COPD

• COPD has components of both chronic bronchitis and emphysema.
• Chronic bronchitis involves chronic inflammation of bronchiole.
• Emphysema involves destruction of alveoli sacs.
• Risk factors for COPD include cigarette smoking, occupational chemicals/dust, and air pollution.
• It is characterized by airflow limitation that is not fully reversible, and generally progressive
• Represents an abnormal inflammatory response of lungs to noxious particles or gases
• Smoking effects lead to increased mucus production
• There is hyperplasia of mucus glands, where cells become larger
• Ciliary activity is lost or decreased
• Intense or prolonged exposure to dusts, vapors, irritants, or fumes can result in COPD
• High levels of air pollution
• Fumes from indoor heating or cooking with fossil fuels.
• Defining features are irreversible airflow limitations during forced exhalation due to loss of elastic recoil
• Airflow obstruction due to mucous hypersecretion, mucosal edema, and bronchospasm.
• Inhalation of noxious particles and inflammation are primary drivers of the disease
• Mediators are released that cause damage to lung tissue.
• Airways become inflamed and the parenchyma destroyed

COPD – Pathophysiology Continued

• Supporting structures of lungs are destroyed.
• Air goes in easily, but remains in the lungs.
• Bronchioles tend to collapse.
• Barrel-chest is associated with air-trapping.
• Pulmonary vascular changes can occur
• Blood vessels thicken.
• Surface area for diffusion of O2 decreases, leading to a hypoxic state.
• Common characteristics are mucous hypersecretion, dysfunction of cilia, hyperinflation of lungs, and abnormal gas exchange.
• Commonly, emphysema and chronic bronchitis coexist
• Distinguishing symptoms can be difficult with co-morbidities.
• COPD often develops slowly and is considered when there is presence of a cough
• Sputum with color change; Yellow/green color may indicate a bacterial infection
• Dyspnea
• Requires exposure to risk factors

COPD – Clinical Manifestations Continued

• Chest breathing is common and dyspnea prompts medical attention as increased work of breathing is metabolically demanding.
• Often present at rest with advanced disease.
• Use of accessory and intercostal muscles is used to breath.
• Characteristically underweight with adequate caloric intake, and chronic fatigue
• Physical examination findings: prolonged expiratory phase, wheezes, decreased breath sounds, increased anterior-posterior diameter, and bluish-red color of skin.
• Cyanosis indicates a hypoxic state.
• Overproduction of RBCs to compensate for hypoxia.

Medications Used to Treat Asthma and COPD

• Bronchodilators include Beta2-adrenergic agonists, anticholinergics, and xanthine derivatives.
• Anti-inflammatory agents include leukotriene receptor antagonists, corticosteroids, and new asthma medications.

Bronchodilators: Beta2Agonists

• They stimulate Beta2 adrenergic receptors in the bronchial smooth muscle throughout lungs to cause bronchodilation via relaxing/opening muscles

• Three subtypes of drugs based on selectivity for receptors exist: nonselective adrenergic drugs, nonselective beta-adrenergic drugs, and selective beta2 drugs.

• Non-selective drugs have more side effects.

• Short-acting inhalers/nebulizers (SABA rescue inhalers): albuterol (Ventolin, Proventil), levalbuterol (Xopenex) and terbutaline (Brethine) have a rapid onset and are short-lived

• Long-acting (LABA, maintenance): salmetrol (Serevent), formoterol (Foradil), arformoterol (Brovana) are prescribed for maintenance.

• Indications: relief of bronchospasm related to asthma, bronchitis, and other pulmonary diseases

• Used in treatment and prevention of acute and chronic attacks depending on their onset of action.

• Further indications: hypotension, shock, uterine relaxation.

• Adverse effects: tremors, tachycardia, vascular headache, insomnia, and restlessness

• Overuse of Albuterol results in loss of its beta2-specific actions at larger doses activating beta1 receptors that causes nausea, increased anxiety, palpitations, tremors, and increased heart rate

• Ensure that patients take medications exactly as prescribed, with no omissions or double doses.

• Inform patient to report insomnia, jitteriness, restlessness, palpitations, or chest pain.

Bronchodilators (Anticholinergics):

• Bronchial tree contains Acetylcholine which causes bronchial constriction and narrowing of the airways
• Anticholinergics bind to the ACh receptors, preventing ACh from binding to reduce bronchial constriction and dilate, and causes a reduction of secretions
• Main indication: Prevention of bronchospasm associated with COPD, allergen and exercise induced asthma.
• Ipratopium bromide (Atrovent), tiotropium (Spiriva), aclidinium (Tudorza), and umeclidinium and vilanterol (Anoro Ellipta. are taken via inhaler or nebulizer
• These have a slow and prolonged action
• Used to prevent bronchoconstriction and NOT used for acute asthma exacerbations
• Side effects include dry mouth or throat, hoarseness, nasal congestion, headache, coughing, anxiety, heart palpitations, and urinary retention.
• Nursing implications include instructing patient to rinse mouth after medication administration.

Bronchodilators: Xanthine Derivatives

• Example: theophylline (Theo-Dur, Elixohyliin) that can be administered orally, rectally, and intravenously - Emergency only
• Mechanisms causes relaxation of bronchial smooth muscle resulting in bronchodilation by increasing camp.
• Leads to smooth muscle relaxation, bronchodilation, and increased airflow.
• Dilation of airways in asthmas, chronic bronchitis and emphysema.
• Used as an adjunct drug in the management of COPD, but is not used as frequently because of potential for drug interactions and variables related to drug levels in the blood (toxicity)
• Adverse effects include nausea, vomiting, anorexia, GERD, dysrhythmia, and seizures

SDOH

• Albuterol is relatively cheap and can cost between $30 and $60 without insurance
• With insurance it costs between $5 and $50 depending on copay
• Ipatroprium bromide-without insurance costs $200
• Theophylline costs $100 per month without insurance
• Prescription access to provider is required
• Consider environmental factors like exposure to pests, mold, air pollution (including secondhand smoke)

Anti-inflammatory Medications

Leukotriene Receptor Antagonists (LTRAs)

• Has action on eosinophil reaction.
• Route of administration is PO
• Examples include montelukast (Singulair) (once daily dosing), zafirlukast (Accolate), zileuton (Zyflo)
• Long term therapy of asthma in adults and children.
• Also used for prevention of exercise induced bronchospasm, and management of seasonal allergies
• Mode of Action modifies the immune response.
• Leukotrienes are substances released when a trigger (allergen) starts a series of chemical reactions in the body and cause inflammation, bronchoconstriction, and mucus production.
• LTRAs function by preventing leukotrienes from attaching to receptors on cells in the lungs and in circulation
• Montelukast (Singulair)- Neuropsychiatric effects in children and adolescents
• Zafirlukast (accolate)-headache, nausea, diarrhea, liver dysfunction
• Zileuton(Zyflo)- headache, dyspepsia, nausea, dizziness, insomnia, liver dysfunction
• Ensure that the drug is being used for chronic management, not acute episodes
• Improvement should be seen in about a week
• Assess liver function before beginning therapy for Seasonal allergies before beginning therapy
• Teach patient to take medications every night on a continuous schedule, even if symptoms improve
• An exception is if symptoms are related to sports or exercise, take two hours prior to activity

Corticosteroids

• Anti-inflammatory properties.
• Inhaled forms reduce systemic effects
• Oral form is not for acute exacerbations
• IV form can be used for acute asthma or COPD exac
• May take several weeks before full effects are seen.
• Stabilize membranes of cells that release harmful bronchoconstriction substances from leukocytes
• Increases responsiveness of bronchial smooth muscle to beta-adrenergic stimulation
• Beclomethasone dipropionate (Beclovent, Vanceril)
• Budesonide (Pulmicort)
• Triamcinolone acetonide (Azmacort)
• Fluticasone (Flovent, Flonase)
• Fluticasone and salmeterol (Advair)
• Bronchospastic disorders are not controlled by conventional bronchodilators
• Not considered first-line drugs for management
• Pharyngeal irritation
• Coughing
• Dry mouth
• Oral fungal infections/thrush
• Systemic effects are rare because low doses are used for inhalation therapy
• Teach patients to gargle and rinse the mouth with lukewarm water afterward to prevent the development of oral fungal infections
• A beta-agonist bronchodilator should be used before the corticosteroid allows for delivery

Inhaled Corticosteroids: Nursing Implications

• Teach patients to monitor disease with a peak flow meter.
• Encourage use of a spacer device to ensure successful inhalations.
• Teach patient how to keep inhalers and nebulizer equipment clean after uses.

Oral Corticosteroids

• Example: prednisone, prednisolone.
• Indications: short-term therapy following and acute asthma episode, copd exacerbation.
• Long-term therapy for acute asthma.
• Side effects of long term therapy: Suppression of adrenal gland function, bone loss, hyperglycemia, glycosuria, myopathy, peptic ulcer disease, infection, and fluid and electrolyte imbalance.

Intravenous Corticosteroids

• hydrocortisone sodium succinate (Solu-cortef) and Methylprednisolone sodium succinate (Solu-mederol)
• Short term IV agents used for acute exacerbations of COPD and status asthmaticus.
• Similar to side effects of long-term oral therapy.
• Monitor patients closely when switched to inhaled steroids after receiving systemic steroids due to adrenal insufficiency.
• Fluticasone/Salmeterol, Budesonide/Formoterol are found in Inhalers
• Ipratropium/Albuterol is found in Inhalers, Nebulizers
• Combination inhaled corticosteroid and long-acting bronchodilator

SDOH

• Disproportionate burden of COPD occurs in people of low socioeconomic status (SES) due to differences in health behaviors, social structure, environmental exposures, tobacco use, occupations with exposure to inhalant toxins
• Leukotriene Receptor Antagonists are $8-$30 and are more expensive than than bronchodilators.
• Inhaled corticosteroids cost $200 (without insurance).
• Oral steroids start at $5 (much cheaper than others).

Newest Medications

• Phosphodiesterase-4 inhibitor (FDA approval 2011), such as roflumilast (Daliresp) taken Orally is used for COPD exacerbations and can cause anxiety and depression
• Monoclonal Antibody (Binds to IgE limits release of chemical mediators of inflammation), such as omalizumab (Xolair) is used for asthma and administered Subcutaneously every two to four weeks to as an Antiasthmatic that requires monitoring for anaphylaxis
• Other mediations use the patient as last resort

Nursing Implications for medication

• Encourage patients to take measures that promote good health to prevent relieve, or decrease symptoms of COPD.

• Avoid exposure to conditions that precipitate bronchospasm, have adequate fluid intake, and comply with medical treatment.

• Patients should also avoid excessive fatigue, heat, extremes in temperature, and caffeine

• Advocate for vaccinations.

• Encourage patients to get prompt treatment for flu or illnesses, and vaccinations

• Encourage patients to check with their physician before taking any other medication.

• Teach patients to take bronchodilators exactly as prescribed.

• Ensure they know how to use devices and to demonstrate use of the devices.

• Monitor for adverse effects.

• Assessment should be done by reviewing skin color, checking baseline vital signs, listening to respirations (work of breathing), respiratory assessment including pulse oximetry, sputum production, known allergies, history of respiratory problems and other medications

Nursing impliations Continued

• Decreased dyspnea
• Decreased wheezing, restlessness, and anxiety
• Improved respiratory patterns with return to normal rate and quality
• Improved activity tolerance
• Decreased symptoms and increased ease of breathing

Inhalers: Patient Education

• Ensure that the patient is able to self-administer
• Provide demonstration and return demonstration
• Patient knows the correct time intervals for Inhalers
• Provide a spacer if the patient has difficulty coordinating if they have to coordinate breathing.
• Patient knows how to keep track of the number of doses in the inhaler device
• Show the patients the red, yellow and green zones that should follow. and when to administer their medication.