Obstructive lung disease Flashcards
COPD definition
Irreversible progressive disease state causing airflow limitation in lungs.
Causes
- Emphysema
- Chronic bronchitis
- Small airway fibrosis
Pathophysiology
Chronic inflammation affecting;
- Central and peripheral airways
- Lung parenchyma, alveoli and vasculature.
- Inflammatory cells stimulated by inhaled stimuli: macrophages, neutrophils
Pathological changes in lungs
- Narrowing/ remodelling of airways
- Increased globet cells
- Enlarged mucus secreting glands in central airways
- Vascular bed changes
COPD risk factors
Tobacco smoking
- Most common
Indoor air pollution
Alpha-1 antitrypsin deficiency
Occupational exposures
- Vapours
- Gases
- Dusts
- Fumes
Alpha-1 antitrypsin deficiency
- Pathology
- Genetics
Enzyme is involved in inhibitng neutrophil elastase (protease inhibitor) from breaking down alveoli.
- Causes emphysema, liver cirrhosis
Genetics
- Autosomal dominant
Chronic bronchitis
- Description, pathology
- Presentation
Productive cough lasting a least 3 months in TWO consecutive years.
- Inflammation and irritation of airways leafs to overproduction of mucus from goblet cells
- Narrowing of the airways, limiting airflow leads to COPD
Presentation
- Chronic, productive cough, typically worse after awakening
- Colourless sputum.
- Recurrent infections
- Dyspnoea
Emphysema
- Description
- Pathology
- Causes
Breakdown of alveolar tissue
- Causes pneumatosis (air filled cavities)
- Reduces surface area of gaseous exchange
Causes
- Smoking
- Alpha-1 antitrypsin deficiency
COPD features
- Clinical features
Cardinal features
- Progressive dyspnoea: start off exertional, then at rest.
- Productive, chronic cough
- Wheeze
- Frequent winter bronchitis
Other features
- Weight loss, cachexia
- Fatigue
- Chest pain
- Ankle swelling (cor pulmonale)
- Haempotsis
- Hands: clubbing, cyanosis, tremor, asterixis.
- Hyper-resonance chest
- Chest wall changes: barrel chest,
Diagnostic investigation for COPD
First line= Spirometry
- Obstructive/ mixed pattern
- FEV1< 80
- FEV1/ FVC ration < 70
Post-bronchodilator spirometry= confirms COPD
Conservative management of COPD
Smoking cessation
Pulmonary rehab
Influenza vaccine/ pneumococcal vaccine
Complications of COPD
Type 2 resp failure
Secondary polycythemia
- Due to chronic hypoxaemia
Cor-pulmonale
Bronchiectasis
Osteoporosis
- Steroid, smoking
Mental health
Medical management for COPD
- SABA or SAMA as needed
- Asthma features
- LABA and ICS
Non-asthmatic
- LABA AND LAMA
- LABA, LAMA, ICS
GOLD Groups of COPD (A-D)
Group A
- Few symptoms
- low risk of exacerbation
Group B
- More symptoms
- Low exacerbation risk
Group C
- Few symptoms
- High exacerbation risk
Group D
- High risk, more symptoms
COPD stages
- 1-4, according to FEV1
Stage 1: mild
- FEV1> 80
Stage 2: Moderate
- FEV1 = 50-79%
Stage 3: Severe
- FEV1= 30-49%
Stage 4: Very severe
- FEV1 <30
SABA used for COPD
Salbutamol
- Bronchodilator
- First line for Group B
LABA used for COPD
Salmeterol, formoterol
- used when symptoms persist with SABA
Add LAMA if symptoms still persist
- Add ICS if asthmatic features and symptoms persist
LAMA used for COPD
Long acting antimuscarinic
- AcH causes smooth muscle contraction, so inhibition causes bronchodilation
Examples
- Ipratropium bromide (Atrovent)
- Glycopyronium
- Alclidinium
ICS used for COPD
USed in patients with asthma features
- Beclamethasone
Roflumilast
Phosphodiesterase-4 inhibitors
- Anti-inflammatory drug
- enzyme degrades cAMP
Used to prevent further COPD exacerbations
Acute exacerbation of COPD
- Causes
Potentially life-threatening exacerbation of COPD
- Causing deterioation of symptoms
Causes
- Respiratory infections: Strep pneumoniae, H influenzae.
- Viral infections: rhinovirus, influenza, RSV
- Pollutants
Management of Acute exacerbation of COPDCOPD
Usual ABCDE approach
Oxygen
- Aim for 88-92%, can give high flow if very hypoxic initially
Nebulised salbutamol
- Progress to ipratropium if Salbutamol not working
- IV theophylline if above fails
Steroids orally
- Prednisolone
- IV hydrocortisone
IV access for anitbiotics and fluids
Antibiotics
- If purulent sputum production/ signs of pnuemonia
- First line PO: amoxicillin, doxycycline, clarithromycin
- Second line: Co-amoxiclav, levofloxacin, trimethroprim
- IV antibiotics: Amoxicillin, co-amoxiclav, clarithromycin, trimethoprim, Tazocin
Additional investigations for COPD
Chest XR= excludes other pathology
- Increased AP ratio/ hyperinflation
- Flattened diaphragm
- Hyperlucent lungs
FBC
- Anaemia + polycythemaia
BMI
Blood gas
- Hypoxia
- Type 2 resp failure
ECG/ echo
- assess for cardiac disease/ pulmonary hypertension
Serum alpha-1 antitrypsin (if no smoking history)
What scale is used to assess breathlessness in COPD
MRC scale
First-line pharmacological management of COPD
SABA
- used for dyspnoea and exercise intolerance
When is LAMA + LABA indicated in COPD
In non-asthmatic features +
Symptomatic despite smoking cessation & SABA
Indications for LAMA+LABA+ICS in COPD
In those taking LABA+ICS/LAMA who have
- severe exacerbation requiriing hospitalisation
- 2+ moderate exacerbations in a year.
Oral therapies in COPD and their indications
Corticosteroids
Theophylline
- After using SABA and LABA
- Or when inhaled is not appropiate
Mucolytics
- Chronic sputum production
Indications for long term oxygen therapy in COPD
Non-smoker
PaO2 <7.3 kPa OR
7.3-8kPa AND
- Polycythemia
- Peripheral oedema
- Pulmonary
hypertension
What vaccinations should be offered in COPD
Pneumococcal
Annual flu
Indications for oral prophylactic antibiotic therapy in COPD
- Non-smoker
- Optimal pharamcological therapy
- Vaccinated
AND - frequent exacerbations (4+/ year with sputum)
- Hospitalised exacerbation
What antibiotic is used as prophylactic antibiotic therapy in COPD
Azithromycin 250 mg 3x/ week
Baseline tests before starting azithromycin
ECG (QT)
LFTs
Gold standard investigation for bronchiectasis
High resolution CT Chest
- Bronchial wall thickening
- Signet ring sign
