Definition: Chronic Obstructive Pulmonary Disease (COPD) is a preventable, treatable, but often progressive disease characterized by persistent airflow limitation.
Characteristics:
Associated with an enhanced chronic inflammatory response in the airways and lungs.
Primarily caused by cigarette smoking and other noxious particles and gases.
Exacerbations and other coexisting illnesses contribute to the overall severity of the disease.
Components of COPD:
Chronic Bronchitis: Defined as the presence of cough and sputum production for at least 3 months in each of 2 consecutive years due to an overflow of mucous secretions.
Emphysema: Characterized by the destruction of alveoli without fibrosis.
Risk Factors
1. Smoking
Effects of Smoking:
Causes hyperplasia of goblet cells, leading to increased mucus production and reduced airway diameter.
Results in loss or decrease in ciliary activity.
Causes abnormal distal dilation and destruction of alveolar walls.
Chronic, enhanced inflammation leads to airway remodeling.
Oxidative Stress: An imbalance between proteases (which break down lung connective tissue) and antiproteases (which protect the lungs).
Passive Smoking (Environmental Tobacco Smoke or secondhand smoke):
Higher risk of exposure to non-filtered smoke.
Increases risk for lung and sinus cancer, decreased pulmonary function, and severe lower respiratory infections (like pneumonia).
Increased respiratory symptoms.
Pack Years Calculation:
Defined as: ext{Cigs/day} imes ext{Years smoked} / 20
2. Occupational Chemicals and Dust
COPD can develop independently of smoking when exposed to prolonged dust, vapors, irritants, or fumes, including:
Air pollution.
Fumes from indoor heating.
Cooking with fossil fuels.
3. Heredity
In some smokers, COPD develops while in others it does not due to genetic risk factors:
α1 Antitrypsin Deficiency (AATD): An autosomal recessive disorder affecting the lungs and liver, accounts for about 3% of COPD cases.
AATD protects the lungs from proteases during inflammation, which makes the deficiency problematic.
Deficiency results in premature bullous emphysema, while smoking accelerates the disease progression.
4. Infection & Illness
Associated Conditions:
Severe recurring respiratory tract infections in childhood linked to reduced lung function and increased respiratory symptoms in adulthood.
Individuals with HIV who smoke have accelerated development of COPD.
History of tuberculosis and asthma can also be risk factors.
5. Aging
Age-related Changes:
Gradual loss of elastic recoil in the lungs leading to increased chest stiffness.
Decreased exercise tolerance.
Changes in rib cage shape due to increased residual volume, resulting in enlargement and rounding.
Decreased number of functional alveoli and surface area for gas exchange.
Osteoporosis: May lead to slouched posture affecting lung function.
Pathophysiology of COPD
Inflammatory Process:
Initiated by inhalation of noxious particles and gases which causes tissue destruction and disrupts the lung's normal defense mechanisms and repair processes.
Chronic inflammation leads to:
Vasodilation, resulting in edema and congestion not effectively cleared by coughing.
Principal characteristic is the inability to expire air, as peripheral airways obstruct and progressively trap air during expiration.
Resulting in:
Hyper-expansion of the chest, leading to a barrel-shaped appearance due to ineffective respiratory muscle function.
Dyspnea: Patients experience difficulty breathing even in a non-exercising state, likened to trying to take another breath with over-inflated lungs.
Air trapping increases, causing alveolar wall destruction and formation of bullae and blebs (ineffective gas exchange), which results in:
Hypoxemia and hypercapnia (especially in late and severe stages).
Pulmonary Hypertension may develop late in COPD:
Caused by small pulmonary arteries vasoconstricting due to hypoxia, leading to right ventricular hypertrophy and potentially right-sided heart failure.
Clinical Manifestations
Symptoms to Consider for Diagnosis:
Chronic cough.
Dyspnea (shortness of breath).
Wheezing.
Sputum production.
History of exposure to risk factors (e.g., tobacco smoke, occupational dust).
Orthopnea (difficulty lying flat).
Fatigue.
Polycythemia and increased hemoglobin (compensation for hypoxemia).
Weight loss and anorexia.
Barrel chest due to air trapping.
Prolonged expiratory phase and pursed lip breathing.
Tripod position utilization and use of accessory muscles in the shoulders and neck.
Dependent Edema: May indicate right-sided heart involvement (Cor Pulmonale).
Clubbing.
Respiratory acidosis.
Cough: An intermittent, sometimes productive, symptom that often develops first.
Dyspnea:
Typically progressive, initially occurring with exertion and becoming present every day.
Patients may describe symptoms as chest heaviness, gasping, and increased effort in breathing.
In late stages, dyspnea can inhibit activities of daily living (ADLs).
Respiratory Mechanics:
Effective abdominal breathing is decreased due to a flattened diaphragm from over-inflated lungs, leading to reliance on chest breathing and use of intercostal and accessory muscles.
COPD Characteristics
General Symptoms:
Easily fatigued.
Frequent respiratory infections.
Use of accessory muscles to breathe.
Orthopneic.
Wheezing.
Pursed-lip breathing.
Chronic cough and barrel chest.
Dyspnea and prolonged expiratory time.
Increased sputum production, digital clubbing, and potential cor pulmonale in late stages.
Complications of COPD
1. Exacerbations
Identification: Signaled by changes in usual dyspnea, cough, or sputum characteristics, often related to infections (bacterial or viral).
Assessment Findings:
Increased dyspnea, sputum volume, or purulence.
Symptoms may include malaise, insomnia, fatigue, depression, confusion, decreased exercise tolerance, increased wheezing, or fever.
Interventions:
Administration of short-acting bronchodilators, systemic corticosteroids, and anticholinergics.
Increase humidification, use of nebulizers, and oxygen supply (targeting SpO2 of at least 92%).
Use of antibiotics if bacterial infection is suspected.
Consider sputum cultures and diuretics as needed.
Implement postural drainage techniques.
Patient Education: Teaching about early recognition of exacerbation signs (increased dyspnea, sputum volume, or purulence) to prevent hospitalization and potential respiratory failure.
2. Cor Pulmonale (Right Ventricular Failure)
Late Manifestation:
Pulmonary Hypertension caused primarily by constriction of pulmonary vessels due to hypoxia.
Chronic hypoxia stimulates polycythemia, raising blood viscosity and pulmonary vascular resistance, contributing to pulmonary hypertension.
Symptoms:
Dyspnea, S3/S4 heart murmurs, distended neck veins, hepatomegaly with upper quadrant tenderness, ascites, epigastric pain, peripheral edema, and weight gain from fluid retention.
Other signs may include crackles, frothy secretions, fatigue/SOB.
Interventions:
Use of diuretics (e.g., Lasix) while monitoring sodium levels, daily weight assessments, low sodium diets, anticoagulants due to inadequate heart function, and providing supplemental oxygen.
3. Acute Respiratory Failure
Causes:
Exacerbations, Cor pulmonale, sudden discontinuation of bronchodilators and corticosteroids, overuse of sedatives, opioids, or surgical issues following extensive chest/abdomen pain.
Diagnostic Studies
Assessment Techniques:
History and Physical Examination.
Chest X-Ray (CXR): Not diagnostic but may display a flat diaphragm indicative of lung hyperinflation.
Pulmonary Function Tests (PFT) including spirometry.
α1 Antitrypsin level.
Arterial Blood Gases (ABGs): Typically show respiratory acidosis in later stages, characterized by low PaO2, elevated PaCO2, decreased or low-normal pH, and increased bicarbonate levels.
Oxygen saturation measurements.
Electrocardiogram (ECG) to assess right- and left-sided ventricular function.
Sputum specimen analysis.
Exercise testing with pulse oximetry.
Management
Key Interventions:
Cessation of cigarette smoking is critical.
Implement drug therapy (various classes to be detailed below).
Techniques for airway clearance and breathing exercises.
Maintain proper hydration (2 to 3 liters per day if contraindicated).
Vaccinations (annual influenza vaccine and pneumococcal vaccine).
Long-term oxygen therapy if indicated.
Recommended progressive exercise plans, especially for walking and upper body strengthening, along with a pulmonary rehabilitation program.
Nutritional supplementation tailored to individual needs.
Addressing complications associated with COPD, including cor pulmonale, acute exacerbations, and respiratory failure.
Surgical options such as lung volume reduction, bullectomy, and lung transplantation when necessary.
Drug Therapy
1. Bronchodilators
Function: Relax smooth muscle in the airway, improving lung ventilation and preventing bronchospasms.
Routes: Inhalers preferred, also available via nebulizer.
Action: Control bronchospasms, relax smooth muscles around the larger airways (bronchioles).
SE: Blurred vision.
3. Corticosteroids
Function: Provide anti-inflammatory effects.
Administration: Rinse mouth post-use to prevent candidiasis; taper dose to prevent adrenal crises.
Examples:
Oral: Prednisone
IV: Methylprednisolone (Solumedrol)
SE: Mood swings, hypertension, weight gain, photosensitivity, potential for cataracts, and requires food to prevent stomach issues. Long-term use may necessitate calcium supplementation to prevent osteoporosis.
4. Methylxanthines
Example: Theophylline.
Route: Usually oral or IV.
Contraindications: Includes Tagamet, Cipro, Diltiazem; should be taken with food.
SE: Similar to bronchodilators; requires monitoring for toxicity.
5. Leukotriene Modifiers
Function: Anti-inflammatory, taken orally.
Example: Montelukast (Singulair).
Administration: Once daily for prevention of airway edema and spasms.
Oxygen Therapy
Indications: Low amounts administered to treat hypoxemia, aiming for a PaO2 of 60 mmHg and O2 saturation of at least 90% during sleep and exertion.
Benefits: Reduces work of breathing (WOB) and cardiac workload, increases survival rates, enhances exercise tolerance, improves mentation and quality of life, promotes better sleep.
Oxygen Delivery Systems
Low Flow: Mixes with room air; oxygen amount depends on patient's breathing.
Examples: Nasal cannula, trach collar, face tent.
High Flow: Provides a set amount of oxygen at a fixed rate regardless of breathing.
Examples: Venturi mask, non-rebreather mask.
Humidification and Nebulization: Essential for patients receiving >2 L/min of oxygen to prevent drying of mucosa and retained secretions (using sterile distilled water).
Surgical Treatment for COPD
Lung Volume Reduction Surgery: Removes approximately 30% of the most diseased lung areas to enhance the performance of the remaining lung tissue and promote better gas exchange.
Bullectomy: Involves the removal of large bullae to improve lung function and gas exchange.
Lung Transplantation: Generally more difficult to find donor organs; single lung transplant is most common due to shortages.
Non-Pharmacological Interventions
1. Pursed-Lip Breathing
Technique: 2 counts inhalation through the nose, 4 counts exhalation through pursed lips.
Benefits: Prolongs exhalation, prevents bronchiolar collapse and air trapping, facilitates CO2 clearance.
2. Diaphragmatic Breathing
Technique: Focuses on using the diaphragm rather than accessory muscles for maximum inhalation and slower respiration rate.
Patient should feel abdomen protrude during inhalation and contract during exhalation.
3. Huff Coughing
Method: Deep abdominal breaths followed by leaning forward and huffing 3-4 times per exhale to aid in secretion mobilization.
4. Chest Physiotherapy
Purpose: Assists in clearing difficult secretions, mucus plugs, and retained secretions in artificial airways.
Methods:
Postural drainage.
Percussion (hands in cupped position, avoiding bony areas).
Vibration techniques.
Use of high-frequency chest compression vests or flutter devices.
Aerosol-nebulization therapy tailored based on CXR and lung sounds.
Timing: Therapy performed 2-4 times per day, administered an hour before meals or 1-3 hours after meals, with bronchodilators given 15 minutes prior.
Nutritional Therapy
Challenges: Patients often experience weight loss and malnutrition due to difficulty eating and breathing.
Interventions:
Rest for 30 minutes prior to meals.
Administer bronchodilators before eating.
Meal prep strategies to facilitate eating (5-6 small meals advised).
Favor cold foods over hot ones to minimize fullness sensation.
Avoid high-chewing foods and gas-forming foods.
Plan rest periods away from meals (1 hour before and after).
Recommend high-calorie, high-protein diets (aim for 3L of fluids per day).
Patient Teaching
1. Infection Prevention
Strategies: Wash hands regularly, avoid crowded places, receive flu and pneumonia vaccines, stay alert for signs of infection.
2. When to Call the Doctor
Symptoms of Concern:
Fever or chills.
Increased shortness of breath beyond usual levels.
More wheezing or coughing than normal.
Changes in sputum characteristics (thickness or color).
Swelling in ankles/legs and puffiness around eyes.