COPD and bronchiectasis Flashcards
What is COPD characterised by?
- Persistent respiratory symptoms
- Airflow limitation
What is COPD?
- Occurs due to airways and/or alveolar abnormalities
- Caused by significant exposure to noxious particles and gases
What is the pathophysiology of disease for COPD?
- Airway inflammation, airway fibrosis, and luminal plugs all cause increased airway resistance
- Loss of alveolar attachments and decrease of elastic recoil lead to parenchymal destruction
- Results in airflow limitation
What conditions make up COPD?
- Chronic bronchitis (due inwards inflammation of small airways)
- Emphysema
- Asthma
What is the aetiology of COPD?
- Biomass exposure
- Smoking
- Genetic (alpha 1 anti-trypsin deficiency)
- Air pollution
- Illicit drug use
What accelerates onset of COPD?
- Not everybody’s lungs grow to full capacity
- E.g. due to prematurity, poor nutrition, poor socio-economic background
- Less lung capacity to lose accelerates onset of COPD
How is COPD diagnosed?
- Symptoms e.g. SOB, chronic cough, sputum
- Risk factors e.g. host factors, tobacco, occupation, pollution
- Spirometry is required to establish diagnosis
What are the symptoms of COPD?
- Dyspnoea
- Chronic cough
- Chronic sputum production
- Recurrent lower respiratory tract infections
- History of risk factors
- Family history of COPD and/or childhood factors
What is dyspnoea like in COPD?
- Progressive over time
- Characteristically worse with exercise
- Persistent
What is a chronic cough like in COPD?
- May be intermittent and may be unproductive
- Recurrent wheeze
What are the risk factors that may lead to COPD?
- Host factors (genetic factors, congenital/developmental abnormalities etc.)
- Tobacco smoke
- Smoke from home cooking and heating fuels
- Occupational dusts, vapours, fumes, gases and other chemicals
What childhood factors might predispose someone to COPD?
- Low birthweight
- Childhood respiratory infections
What are the signs of COPD?
- Purse lip breathing
- Hyperinflation or barrel-shaped chest
- Prolonged expiratory phase
- Maybe wheeze on auscultation
- In advanced cases: cyanosis and cor pulmonale
Outline how spirometry works
- Measure of how much and how fast a person can breathe out
- Patient takes a deep breath and blows as hard as possible into tube
- Technician monitors and encourages patient during test
What does spirometry measure?
- Forced expiratory volume in 1 second
- Full vital capacity i.e. how much air is expelled in one breath
How does COPD change spirometry traces?
- Takes longer to breathe out due to obstruction
- FVC and FEV1 are decreased
- FVC:FEV1 ratio decreases
What other investigations are used to identify COPD?
- Chest X-ray
- HRCT
- Full pulmonary function tests
- ABG if suspicion of respiratory failure
- Alpha-1- antitrypsin deficiency blood test for younger patients
Why is a chest X-ray used in patients with COPD?
- May suggest hyperinflation
- Mandatory to exclude other diagnoses
Why is HRCT used in patients with COPD?
- Detailed assessment of degree of emphysema
- If suspicion of bronchiectasis
- Not required for routine assessment of COPD
Why are full pulmonary function tests used in patients with COPD?
- Static lung volumes can assess for hyperinflation
- Gas transfer to look at alveolar destruction
Define an exacerbation of COPD
- An acute worsening of respiratory symptoms that result in additional therapy
What common bacteria cause COPD exacerbations?
- Haemophilus influenzae
- Streptococcus pneumoniae
- Moraxella catarrhalis
What common viral pathogens cause COPD exacerbations?
- Rhinoviruses
- Coronavirus
- Influenza
What therapies for COPD improve symptoms?
- Pulmonary rehabilitation
- Bronchodilators (beta 2 agonists and anti-muscarinics)
- Mucolytics
-Lung volume reduction surgery - Lung transplant
What therapies improve risk in COPD?
- Smoking cessation
- Anti-inflammatories (inhaled corticosteroids and long-term macrolides)
- Oxygen therapy
- Non-invasive ventilation
How does smoking cessation improve COPD?
- Reduces mortality
- Improves symptoms
- Slows down loss of lung function
- Reduces exacerbations
- Drugs work better
What therapies can help patients to stop smoking?
- Nicotine replacement therapy
- Champix
- Behavioural support
- Vaping
What does pulmonary rehabilitation entail?
- 6-8 week course
- Hospital or community basis
- 2 supervised sessions/week
- 1 unsupervised/week
- Education programme
- Referral or ongoing plan onto maintenance therapy
What are the effects of antimuscarinic agents on the airways?
- More effective in proximal airways
- Inhibit bronchoconstrictor effect of ACh at M3 muscarinic receptors located on airway smooth muscle
What are the effects of B2 agonists?
- More effective in distal airways
- Directly activate B2 receptors in bronchioles, leading to increase in cAMP, relaxation of smooth muscle, and bronchodilation
What are the effects of inhaled corticosteroids?
- Reduce exacerbation frequency
Outline long term oxygen therapy
- Extended periods of hypoxaemia cause end-organ damage to heart and kidneys
- Given if pO2 <7.3kPa at rest
- For minimum 16 hours/day
- Improves survival
- Non-smokers
- Safety - home fire risk assessment (O2 is very flammable)
Outline ambulatory oxygen
- If patients desaturate by >4% when walking
- Use during exertion
- Need to walk further on oxygen
- No prognostic benefit
What are the symptoms of bronchiectasis?
- Cough with sputum - produce an eggcup of sputum per day
- Breathlessness
- Recurrent infections/exacerbations
- Haemoptysis
- Weight loss/fatigue/exercise limitation
What are the causes of bronchiectasis?
- Post-infectious (TB, pneumonia, whooping cough)
- Immunodeficiency
- Impaired muco-ciliary clearance
- Airways lesions
- Other chronic respiratory disorders (COPD)
- Auto-immune
- Other syndromes (Marfans, polycystic kidney disease)
How is bronchiectasis diagnosed?
- Productive cough
- Crackles on auscultation
- Hallmarks of other disease
- CXR
- CT scan
- Bloods
How is bronchiectasis treated?
- Airways clearance (physiotherapy, active cycle technique, adjuvant inhaled therapy, mucolytics)
- Low-dose macrolides (antibiotics with anti-inflammatory effect)
- Inhaled corticosteroids and bronchodilators
What additional infections can patients with bronchiectasis cause?
- Pseudomonas aeruginosa
- Non-tuberculous mycobacteria
How does pseudomonas aeruginosa affect patients with bronchiectasis?
- Patients become chronically colonised
- Worsens disease and increases exacerbations
- Limited antibiotics coverage (use ciprofloxacin)
- Treatment involves eradication therapy, nebulised colomycin, easy access to IV abx)
How does non-tuberculous mycobacteria (NTM) affect patients with bronchiectasis?
- Need to screen for it
- Often incidental finding and doesn’t usually need treating
- Some are very aggressive
- 18 month broad spectrum antibiotics
What is bronchiectasis?
- An uncommon condition resulting in dilated, damaged airways
- Results in sputum build up and inflammation
Outline the pathophysiology of cystic fibrosis
- Defect on long arm of chromosome 7
- Leads to CFTR mutation
- Leads to ineffective cell surface chloride transport
- Thick, dehydrated body fluid in organs which have CFTR
