Lower Respiratory Tract & Diseases

Lower Respiratory Tract and Alveoli

• The respiratory tract involves airways that commence at the nose and mouth, leading to the alveolar sacs.
• The airways from the nose and mouth converge at the pharynx.
• Human lungs consist of around 300 to 500 million sacs facilitating gaseous exchange.
• The primary role of the lower respiratory tract centers around the ventilatory cycle.

Common Lower Respiratory Diseases

• Chronic obstructive pulmonary disease (COPD) is a prevalent condition.
• Chronic airflow limitation disease (CALD) significantly affects respiratory function.
• Asthma is characterized by airway inflammation and constriction.
• Chronic bronchitis involves persistent inflammation and productive cough.
• Emphysema is a condition marked by the destruction of alveolar tissue, impairing lung function.

Arterial Blood Gases (ABGs)

• Arterial blood gas analysis includes the following components:
• pH must be between 7.35 to 7.45
• PaCO2 should range from 35 to 45 mm Hg
• PaO2 levels are ideally between 80 to 100 mm Hg.
• HCO3 levels should be 24 to 28 mEq/L
• SaO2 (oxygen saturation) should be at 95%.

Spirometry

• Spirometry assesses the capabilities of the patient's lungs, thorax, and respiratory muscles.
• Spirometers quantify the volumes of air moved during breathing.
• A 15% to 20% improvement in FEV1 (or PEFR) following bronchodilator therapy indicates significant reversibility of airway obstruction.

Asthma

• Asthma is a chronic airway disease.
• It is associated with a high number of hospitalizations, emergency department visits, and healthcare provider office visits.
• Asthma is an inflammatory disease affecting the bronchi and bronchioles.
• Asthma severity is categorized into intermittent, mild persistent, moderate persistent, and severe persistent.

Chronic Bronchitis

• Chronic bronchitis involves inflammation and edema due to chronic irritation.
• A chronic productive cough present for 3 months over 2 successive years, with no other identifiable cause, characterizes chronic bronchitis.
• Patients with chronic bronchitis are prone to recurrent respiratory infections.

Emphysema

• Emphysema is characterized by the destruction of alveolar tissue without fibrosis.
• Classic symptoms of emphysema include dyspnea with minimal exertion and breathing through pursed lips.
• Patients may be thin, barrel-chested, and produce scanty sputum with minimal cough.

Treatment of Lower Respiratory Diseases

• Cough: Treatment is of secondary importance, with primary treatment focusing on the underlying disorder.
• Asthma treatment aims to maintain normal activity levels, near-normal pulmonary function rates, and to prevent chronic symptoms and exacerbations.
• The use of short-acting inhaled beta-2 agonists should be minimized to avoid adverse effects.
• Chronic Obstructive Pulmonary Disease (COPD): Goals include relieving symptoms, improving exercise tolerance, and improving health status.
• Bronchodilators are the cornerstone of COPD treatment.
• Pharmacotherapy recommendations are based on the patient's symptoms and history of exacerbations.
• Long-term treatment with systemic corticosteroids should be avoided.

Drug Therapy for Lower Respiratory Diseases

• Drug therapy focuses on relieving cough symptoms by liquefying thick secretions or suppressing cough.
• Medications used include expectorants, antitussives, mucolytic agents, bronchodilators, antiinflammatory agents, and immunomodulators.

Nursing Assessments

• Obtain the patients history, medications and description of current symptoms
• Perform respiratory assessments: percussion, auscultation, palpation, and inspection.
• Review cardiovascular health, sleep patterns, psychosocial health, laboratory data, diagnostic data, and smoking history recorded in pack years.
• Calculate pack years by multiplying the number of packs smoked per day by the number of years smoking."

Patient Education

• Focus on the use of peak flow meters for asthmatic patients.
• Avoid irritants such as smoking, pollen, and environmental pollutants.

Administration of Inhalants

• Review with patients during each visit and give a demonstration of how to use the inhaler
• Exhale completely before inhaling and hold breath at least 10 seconds afterward
• Administer bronchodilator first, wait several minutes, then administer steroid inhalant
• Rinse mouth after steroid medication
• A spacer is helpful with older or younger patients with questionable coordination

Patient Education and Health Promotion

• Management principles rely on the patient's understanding of the treatment.
• A well-balanced diet is recommended, and patients are encouraged to increase fluid intake.
• Patients should adjust physical activity to reduce fatigue.
• Eliminating risk factors includes stopping smoking and avoiding irritants.
• Proper administration of medications
• the use of peak flowmeters, recording readings, and practicing pursed-lip breathing and postural drainage.

Drug Class: Expectorants

• Drug: Guaifenesin (Robitussin)
• Enhances output of respiratory tract fluid, decreases mucus viscosity, and promotes ciliary action.
• Used to relieve dry, nonproductive cough and treat symptoms of the common cold, bronchitis, laryngitis, pharyngitis, and sinusitis.
• Common adverse effects include GI upset, nausea, and vomiting.

Drug Class: Saline Solutions

• Hydrate mucus and reduces viscosity
• Expectorant administered by nubulization
• No common adverse effects noted

Drug Class: Antitussive Agents

• Drugs: Benzonatate (Tessalon Perles), Codeine, Dextromethorphan (Robitussin, Delsym), Diphenhydramine (Diphen, Tusstat), and Hydrocodone.
• Action: Suppress cough center in the brain
• Uses: Suppress disruptive spasms
• Common adverse effects consist of dry mouth, drowsiness, and constipation.

Drug Class: Mucolytic Agents

• Drug: Acetylcysteine (Mucomyst)
• Action: Dissolves chemical bonds in mucus
• Uses: Dissolves abnormally viscous mucus to treat chronic emphysema, emphysema with bronchitis, asthmatic bronchitis, and pneumonia.
• Common adverse effects include nausea and vomiting (due to odor similar to rotten eggs)
• Serious adverse effect can be bronchospasm

Drug Class: Beta-Adrenergic Bronchodilating Agents

• Action: Stimulates beta receptor within smooth muscle of the tracheobronchial tree
• Use: Reverse airway constriction and is mainstay for all asthma therapy
• Serious adverse effects: Tachycardia, palpitations, tremors, nervousness, anxiety, restlessness, headache, dizziness, nausea, and vomiting

Short-Acting Beta Adrenergic (SABA) Bronchodilators

• Reliever medications treat acute asthma symptoms
• An asthma exacerbation that fails to respond to rescue medication is called status asthmaticus and can quickly progress to life threatening respiratory failure.

Long-Acting Beta-2 Agonists (LABAs)

• Used to prevent acute deterioration
• Not used for acute episodes and patient should have asthma controller medication
• Used for long term control to avoid exacerbation of asthma and COPD
• Oftenly combined with inhaled corticosteroids
• Examples of LABAs consist of salmeterol, formoterol, vilanterol, and arformoterol"

Long-Acting Muscarinic Agents

• Drugs: Ipratropium bromide (atrovent), Tiotropium bromide (Spiriva)
• Action: Produce bronchodialation
• Use: Long term treatment of reversible bronchospasm associated associated with COPD
• Common adverse effects: Mouth dryness, throat irritation
• Serious adverse effects: Tachycardia, urinary retention, exacerbation of symptoms

During Asthma Exacerbation

• Use albuterol first to improve delivery of other inhaled medications given next
• Nursing care focus on administering medications to reverse bronchospasm and inflammation
• Monitor for worsening respiratory distress

Respiratory Antiinflammatory Agents

• Action: Inhibit inflammatory response
• Use: For patients unresponsive to sympathomimetic agents or xanthine derivatives and to prevent symptoms of asthma
• Common adverse effects: Hoarseness, dry mouth
• Serious adverse effect: Thrush

Drug Class: Antileukotriene Agents

• Drugs: Montelukast (Singulair), Zafirlukast (Accolate)
• Action: Selective and competitive receptor antagonist of cysteinyl leukotriene receptor
• Use: In combination with other drugs to treat asthma
• Common adverse effects: Headache, nausea, dyspepsia

Phosphodiesterase-4 Inhibitor Roflumilast (Daliresp)

• Action: Blocks inflammation
• Use: Reduces frequency of flare-ups of inflmmation in patients with chronic bronchitis, severe COPD; used with bronchodilators and corticosteroids
• Common adverse effects: Dyspepsia, cramps, nausea, diarrhea, weight loss, headache
• Serve adverse effects: Insommia, anxiety, depression, suicidal thoughts, mood changes

Drug Class: Immunomodulator Agents

• Drug: Omalizumab (Xolair)
• Action: Bind to circulating IgE antibodies and inhibits mast cell release of inflammatory chemicals
• Treatment of moderate to severe persistent allergic asthma
• Common and serious adverse effects: Hypersensitivity, injection site reactions
• Special medication preparation technique

Miscellaneous Antiinflammatory Agents

• Drug: Cromolyn sodium (Intal)
• Actions: Mast cell stabilizer: inhibits release of histamines and other mediators of inflammation
• Use: In combination with other agents to treat severe bronchial asthma or allergic rhinitis
• Common adverse effects: Oral irritation, dry mouth
• Serious adverse effects: Bronchospasm, coughing