Theme 4: Lecture 10 - Chronic obstructive pulmonary disease Flashcards
What is chronic obstructive pulmonary disease
- Preventable and treatable disease characterised by persistent, progressive airflow limitation (not fully reversible by bronchodilators)
- Enhanced chronic inflammatory response in the lungs to noxious gases/particles
Describe how COPD can occur
Tobacco smoking (or other particles) causes chronic bronchitis which leads to emphysema which leads to airflow obstruction which leads to COPD
Describe the airways in COPD
- Chronic inflammation
- Increased number of goblet cells
- Mucus cell hyperplasia
- Fibrosis
- Narrowing and reduction in the number of small airways
- Airway collapse due to alveolar wall destruction in emphysema (leads to bullae - lots of little holes join together to form a big hole)
What are the 3 disease characteristics are needed for a diagnosis of COPD
- Chronic bronchitis ie large airways inflammation (Chronic productive cough for 3 months in 2 consecutive years, exclude other causes of chronic cough)
- Emphysema (Abnormal and permanent enlargement of the airspaces due to destruction of the alveolar airspace walls. Effects gas exchange)
- Small airways disease (wheeze)
How does chronic bronchitis cause airways to narrow in COPD
Airways narrow due to chronic irritation of the bronchi causing inflammation and changes to the mucociliary escalator, often results in chronic cough
What are the risk factors for COPD
- Cigarette smoke
- Occupational dust and chemicals
- Environmental tobacco smoke
- Indoor and outdoor air pollution
- Genes
- Infections
- Socio-economic status
What should you ask about smoking history
- Age started
- Calculate pack year history
- Times stopped and why failed quit attempt
- Recreational drugs smoked (or other substances eg shisha)
How can COPD lead to respiratory failure and increased mortality
COPD leads to dyspnoea which limits exercise therefore not expanding bases because not breathing as not so not coughing and sputum production isn’t cleared. Patient at greater risk of infection which leads to exacerbations reducing their quality of life and leading to respiratory failure and increased mortality
Diagnosis of COPD
- Symptoms (exertional breathlessness, productive cough, “winter bronchitis”, wheeze) +
- Risk factors (10 pkyr smoking history and age>35 years) +
- spirometry (FEV1/FVC <0.7)
Describe the 5 grades of the MRC dyspnoea scale
1 - Not troubled by breathlessness except on vigorous exercise
2 - Short of breath when hurrying or walking up inclines
3 - Walks slower than contemporaries because of breathlessness or has to stop for breath when walking at own pace
4 - Stops for breath after walking about 100m
5 - Too breathless to leave the house or breathless on dressing/undressing
Physical signs of COPD
- Barrel-shaped chest
- (hyperresonant) percussion
- Accessory muscles
- Prolonged expiration
- Pursed-lip breathing
- Tripod position
- Low BMI
- Nicotine-staining
Physiological effects of COPD
- Increased work of breathing
- Reduced Exercise Tolerance
- Impaired gas exchange leading to hypoxia, hypercapnia, raised pulmonary artery pressure and RV dilatation (cor pulmonale)
- Loss of Fat Free Mass
LAMA
Long acting muscarinic antagonists
Chronic disease management of COPD
- Stop smoking!!!
- If symptomatic LABA/LAMA combined inhaler
- LOTS of inhalers…..
- Flu vaccination
- Educate and Empower
- Treat exacerbations
- Pulmonary rehabilitation
- Think about the whole patient (bones, nutrition, mental health)
- (LTOT)
What is pulmonary rehabilitation
- 2x supervised sessions for 6 weeks
- Supervised exercise
- Education
- Psychosocial support/group work
