15 - COPD Flashcards
What is the definition of COPD?
- Airflow limitation that is not fully reversible. Persistent respiratory symptoms
- Encompasses emphysema and chronic bronchitis
- Airflow usually progressive and abnormal inflammatory response of lungs to nocious particles, usually cigarrete smoking
What is the aetiology of COPD?
- Smoking (90%)
- Air pollution (indoor cooking)
- Occupational exposure
- Alpha 1 Antitrypsin deficiency (early onset)
What are the pathology changes in the lung during COPD?
- Enlargement of mucus glands in central airways
- Increased number of goblet ells
- Ciliary dysfunction
- Breakdown of elastic so destruction of alveolar walls
- Large air spaces
- Vascular bed changes leading to pulmonary hypertension
What is the final outcomes in emphysema and chronic bronchitis?
- Emphysema: elastin breakdown so enlargement of airspaces
- Chronic Bronchitis: Excessive mucus secretion and impaired removal of secretions due to ciliary dysfunction
Why is there an increased airways resistance in COPD?
- Luminal obstruction by secretions
- Narrowing of small bronchioles as loss of radial traction
- Decreased elastic recoil so reduced expiratiory force and air trapping
LEADS TO HYPERINFLATION
Why can Cor Pulmonale occur with COPD?
- Hypoxia due to airway narrowing and loss of lung parenchyma
- Hypoxic pulmonary vasoconstriction and smooth muscle thickening so pulmonary hypertension
What would you see in a history of a patient with COPD?
- Gradual onset
- Older person with history of smoking
- Cough
- Shortness of breath (first on exertion then at rest)
- Sputum
What is the cough like in COPD?
- Usually initial symptom
- Starts as morning cough but becomes more persistent
- Usually productive and sputum quality varies with exacerbations
What are some things you may see on physical examination with a patient that has COPD?
- Tachypnoea
- Use of accessory muscles in respiration
- Barrel chest
- Hyperresonance on percussion due to hyperinflation
- Distant breath sounds
- Reduced air entry
- Wheezing
- Prolong expiration
- Late stages: central cyanosis, flapping tremors, signs of right sided heart failure
What are some signs of right sided heart failure due to COPD?
- Distended neck veins
- Hepatomegaly
- Ankle oedema
All due to pulmonary hypertension from hypoxic vasoconstriction
How do you diagnose COPD?
Spirometry with irreversible changes on administering bronchodilators. Obstructive pattern
How do you measure dyspnoea?
What are some investigations you may do to support your diagnosis of COPD?
- Spirometry: obstructive, ratio<70%, irreversible
- Decreased diffusing capacity of the lung for CO (emphysema)
- CXR for hyper inflated lungs so flattened diaphragm, hyperlucent lungs and increased AP diameter. May also show pneumonia and pneumothorax
- Pulse oximetry and ABG (for home oxyen therapy)
- Alpha 1 Anti Trypsin level
What is an acute exacerbation of COPD?
Event characterised by a change in the patient’s baseline dyspnoea, cough and/or sputum that is beyong normal day to day variations and is acute in onset
Infectious exacerbations are acute, severe SOB, fever and chest pain
Which COPD patients are at risk of COPD exacerbations?
- Previous exacerbations
- GORD
- Pulmonary hypertension
- Respiratory failure
How do we manage exacerbations of COPD?
- Monitoring for hypoxia and hypercapnia through sats and ABG
- Antibiotics, especially for H.Influenzae and S.Pneumonia
- Nebulised bronchodilators
- Oral steroids e.g prednisolone
- 24 or 28% oxygen therapy
- Non-invasive ventilation
How can we tell the difference between asthma and COPD?
- Asthma onset is early in life and personal or family history of allergy, rhinitis or eczema
- Asthma has daily variability and can have wheezing that responds to bronchodilators
- Asthma sputum has eosinophillia
How is COPD treated?
Reduce risk and relieve symptoms
- Smoking cessation and patient education
- Pneumococcal vaccination in patient
- Patient weight, nutrition and physical activity monitoring
- Bronchodilators
- Inhaled corticosteroids
- Pulmonary rehabilitation
- Long term oxygen treatment
- Surgical intervention
What is pulmonary rehabiltation and why does it help to relieve symptoms of COPD?
- Patients avoid exercise because of breathlessness so muscle weakness, worsening symptoms, depression and social isolation
- MDT give them an exercise regime,and disease education
What are the different types of oxygen therapy?
- Long term oxygen therapy: 16 hours a day at home to stop hypoxia and pulmonary hypertension to help survive
- Ambulatory: if patient desaturates whilst walking
What surgical intervention can you do for COPD?
- Removal of large bullae
- Lung volume reduction
- Lung transplant
Used to improve lung dynamics and quality of life
How does acute non-invasive ventilation work?
- Increases the tidal volume to increase ventilation and breathe of CO2
- Also the continuous positive pressure holds the airways open so they don’t collapse
What are some complications that can occur due to COPD?
- Recurrent pneumonia
- Pneumothorax because of lung parenchyma damage with subpleural bulla formation and rupture
- Respiratory failure
- Cor Pulmonale
- Pulmonary hypertension
- Polycythemia
What is a wheeze?
Whistling sound heard mainly on expiration
Due to narrowing of tubes
Why are asthmatics triggered by cold air and smoke?
- TH2 cells are activated by the ‘allergen’ or aggrevator
- B plasma cells are made with IgE and these bind to mast cells
- When antigen presents they bind to IgE and mast cells degranulate
