COPD Flashcards
Define COPD
Chronic progressive irreversible lung disorder characterised by airflow obstruction, chronic bronchitis and emphysema
Chronic Bronchitis: Chronic cough and sputum production on most days for at least 3 months per year over 2 consecutive years
Emphysema: permanent destructive enlargement of air spaces distal to the terminal bronchioles
Aetiology of COPD
Bronchial and alveolar damage due to environmental toxins i.e. smoking
May be caused by alpha-1 antitrypsin deficiency (<1%)
May overlap and co-present with asthma
Aetiology of chronic bronchitis and emphysema
Bronchitis: narrowed airways due to inflammation and mucosal oedema, hypersecretion and squamous metaplasia
Emphysema: destruction and enlargement of alveoli -> loss of elastic traction that keeps them open -> collapse -> bullae formation
Risk factors for COPD
Cigarette smoking
Advanced age, >65
Genetic factors, white ancestry
Exposure to air pollution, burning solid or biomass fuel
Occupation exposure to dusts, chemicals, vapours, fumes or gases
Developmentally abnormal lung
Male sex
Low socio-economic status
Rheumatoid arthritis
Symptoms of COPD
Cough (productive, continuous, chronic)
SOB
Fatigue
Wheeze
Weight or muscle loss
Headache
Reduced exercise tolerance
Signs of COPD on exam
Tachypnoea/resp. distress
Tripod position
pursed lip breathing
Tar staining
Asterixis
Use of accessory muscles
Hyperexpanded chest with reduced expansion
Reduced breath sounds
Hyperresonance
Wheeze
Coarse crackles
Signs of RHF (Cor Pulmonale)
Investigations for diagnosis of COPD
ECG: signs of RVH, arrhythmias, ischaemia (cor pulmonale)
FBC: Raised haematocrit, anaemia, possible leucocytosis | Secondary polycythaemia
Alpha-1 antriptrypsin levels: for young patients without smoking history
BNP: ?cor pulmonale
Spirometry/function tests: FEV1/FVC ratio <0.7
FEV1:
- Mild: >80% predicted
- Moderate: 50-80% predicted
- Severe: 30-50% predicted
- Very severe: <30% predicted
CXR:
- Increased anteroposterior ratio
- Flattened diaphragm
- Hyperexpanded chest
- Increased intercostal spaces
- Hyperlucent lungs
HRCT: hyperinflammation, bullae formation
Echo: ?cor pulmonale
Investigations for COPD exacerbations
ECG: ?cor pulmonale
Sputum cultures: ?infection
ABG: assess sats
FBC: Raised haematocrit, anaemia, possible leucocytosis | Secondary polycythaemia
Blood cultures: ?infection
CRP: ?infection
U&Es
CXR:
- Increased anteroposterior ratio
- Flattened diaphragm
- Hyperexpanded chest
- Increased intercostal spaces
- Hyperlucent lungs
CT: hyperinflammation, bullae formation
Echo: ?cor pulmonale
Features of an acute exacerbation of COPD
Worsening breathlessness with increased sputum volume and purulence
Cough
Wheeze
Fever
URTI in past 5 days
Admission criteria for COPD
Severe breathlessness
Inability to cope at home
Rapid onset of symptoms
Acute confusion or impaired consciousness
Cyanosis
SpO2 <90
Worsening peripheral oedema or new arrhythmia
Management for an acute exacerbation
- A-E assessment
- Oxygen - aim for 94-98 or (88-92% if stable)
- 24% O2 via venturi
- Do ABG <1 hour after changing oxygen
- Aim to raise PaO2 >8 with <1.5kPa rise in PaCO2 - Nebulised bronchodilators with 6L/min O2 over 30-60 minutes
- Salbutamol 5mg inhaled via nebuliser every 20-30 minutes - Ipratropium inhaled 500 micrograms via nebuliser when required
- Steroids oral (prednisolone oral 30mg for 5 days) AND hydrocortisone IV 200mg
- Presence of purulent sputum or clinical signs of pneumonia (Raised WCC, CRP)
- Abx e.g. amoxicillin, doxycycline, clarithromycin (SEVERE)
- Infective exacerbation of COPD: first-line antibiotics are amoxicillin or clarithromycin or doxycycline - Inadequate response to bronchodilator -> theophylline IV
- NIV
- Consider ITU admission
Conservative management for chronic COPD
STOP smoking
influenza (annual) and pneumococcal vaccines (one off)
Pulmonary rehab (aerobic exercise, strength training)
Breathing and chest physio
Mucolytics e.g. carbocysteine
Long-term oxygen therapy (LTOT)
BiPAP
Home news
Rescue pack:
- SOB not solved by inhaler → prednisolone
- Change in volume/colour sputum → doxycycline
Abx prophylaxis with azathioprine
Criteria for LTOT
NON-SMOKER +
- pO2 <7.3 kPa (x2 measurements)
- pO2 7.3-8 kPa +
– Secondary polycythaemia
– Peripheral oedema
– Pulmonary Hypertension
Medical management for chronic COPD
- SABA or SAMA
- No asthmatic features - LABA or LAMA
- Asthmatic features - LABA + ICS
- LABA + LAMA + ICS
What classifies a patient as asthmatic/steroid responsive in COPD
Any previous diagnosis of asthma or atopy
Higher eosinophil count
Substantial variation in FEV1 over time
Substantial diurnal variation in PEFR
