COPD Overview

• 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.
• Types:
  • Short-Acting Beta2 Adrenergic Agonists (e.g., Albuterol)
  • Long-Acting Beta2 Adrenergic Agonists (e.g., Formoterol, Salmeterol)
  • Side Effects (SE): Tremors, tachycardia, nervousness, insomnia, nausea, long-term hypokalemia, CNS stimulation.

2. Anticholinergics

• Example: Ipratropium (Atrovent).
• 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.
  • Heart palpitations or increased heart rate.
  • Loss of appetite.