COPD Flashcards
Symptoms of COPD
Dyspnoea (exertional) Chronic productive cough Recurrent chest infections Weight loss Fatigue Exercise intolerance
Signs of COPD
Wheeze or quiet breath sounds Peripheral oedema and raised JVP (right heart failure) Cyanosis Cachexia Hyperinflated chest Use of accessory muscles Pursed lip breathing
Pathophys of emphysema
Smoking inactivates alpha-1 antitrypsin (or hereditary deficiency) so that this can’t inhibit serum elastase
–> elastic tissues destroyed
–> Loss of elastic fibres of the alveoli and a decreased surface area –> can lead to collapsed alveoli
Can get air trapping as you exhale as the recoil mechanism isn’t working, causing bulla formation
Pathophys of bronchitis
Problem in bronchioles
Smooth muscle hypertrophy and mucus hypersecretion
Risk factors of COPD
Smoking
Genetic factors
Air pollution
Occupational exposure to dust, chemicals, noxious gases etc.
CXR findings in COPD
Flattened diaphragm
Hyperinflation
Describe the airflow obstruction in COPD
Progressive
Not fully reversible
Does not change markedly over several months
How to calculate pack years?
Number of packs per day x number of years smoked
Complications of COPD
Disability and impaired quality of life
Depression and anxiety
Cor pulmonale (right heart failure secondary to lung disease) — caused by pulmonary hypertension as a consequence of hypoxia
Frequent chest infections
Secondary polycythaemia due to hypoxia
Type 2 respiratory failure — caused by increased airway resistance
Lung cancer — COPD may increase the risk of lung cancer
Investigations
Post-bronchodilator spirometry
CXR to exclude other pathology
FBC — to identify anaemia or secondary polycythaemia due to hypoxia
Pulse oximetry
ECG and echo if features of cor pulmonale
Sputum culture
ABG if acutely unwell, FEV1 <35% predicted, sats <92%, or signs of resp failure = shows decreased pa02 +/- hypercapnoea, may see resp acidosis
CT may be done if symptoms disproportionate to spirometry, if any abnormalities on CXR, before surgery etc.
Alpha-1 anti-trypsin if young, minimal smoking, family history
Features of cor pulmonale
Peripheral oedema
Raised jugular venous pressure
Systolic parasternal heave
A loud pulmonary second heart sound (over the second left intercostal space)
Widening of the descending pulmonary artery on chest X-ray
Right ventricular hypertrophy on ECG
Define airflow obstruction using FEV1/FVC
FEV1/FVC ratio of less than 0.7
Grade severity of airflow obstruction using FEV1
Stage 1, mild — FEV1 80% of predicted value or higher
Stage 2, moderate — 50–79%
Stage 3, severe — 30–49%
Stage 4, very severe — <30%
MRC dyspnoea scale
Grades 1-5
Prognostic
1 = not troubled by breathlessness except during strenuous exercise
2 = SOB when walking up slight hill or hurrying
3 = walks slower on the level or has to stop for breath when walking at own pace
4 = stops for breath after walking about 100m or after a few minutes on the level
5 = too breathless to leave house, breathless when dressing/undressing
Differentials for COPD
Asthma Bronchiectasis Heart failure Lung cancer Interstitial lung disease Anaemia Tuberculosis
What is an acute exacerbation of COPD?
Sustained worsening of person’s symptoms from their usual stable state, which is beyond normal day-to-day variations and is acute in onset
Symptoms of acute exacerbation
Increased breathlessness, cough, sputum production, wheeze, chest tightness, fatigue
Change in sputum colour
Upper respiratory tract symptoms (e.g. cold or sore throat)
Reduced exercise tolerance
Ankle swelling
Acute confusion
Fever
Differentials for acute exacerbation of COPD
Pneumonia Recurrent aspiration Pneumothorax Acute heart failure Pulmonary embolism Lung cancer Pleural effusion Upper airway obstruction
When to refer for pulmonary rehabilitation?
If functionally disabled by COPD e.g. MRC dyspnoea scale grade 3 or above
OR have had a recent hospitalization for an acute exacerbation
Benefits of pulmonary rehab
Improve QOL, increase exercise capacity, reduce breathlessness
When to refer to physio
If excessive sputum, to learn the use of positive expiratory pressure masks and the ‘active cycle of breathing’ technique.
Define chronic bronchitis
Presence of chronic productive cough and sputum for at least 3 months in each of two successive years.
Pathophys of COPD
Chronic inflammation (i.e. due to the inhaled stimuli)
- -> narrowing and remodelling of airways, enlargement of mucus glands
- -> increased airway resistance due to decreased elastic recoil (smoke causes release of serine elastase which destroys elastic tissue), fibrosis, luminal obstruction of airways by secretions
- -> hyperinflation and destruction of lung parenchyma
- -> hypoxia
- -> vascular smooth muscle thickening
- -> pulmonary hypertension
Causes of COPD
Smoking
Air pollution
Occupational dusts, chemicals, fumes
Alpha-1 anti-trypsin deficiency
Fundamentals of COPD care
Smoking support/cessation Pneumococcal and flu vaccines Pulmonary rehab if indicated Personalised self-management plan Optimise treatment for comorbidities
Inhaled therapies for COPD
- if asthmatic features or features suggesting steroid responsiveness
1) SABA or SAMA as needed
2) LABA + ICS
3) LABA + LAMA + ICS
4) Explore further treatment e.g. theophylline, oral mucolytic therapy, long term oxygen therapy
Inhaled therapies for COPD
- if NO asthmatic features or features suggesting steroid responsiveness
1) SABA or SAMA as needed
2) LABA + LAMA
3) LABA + LAMA + ICS (3 month trial unless has 1 severe or 2 moderate exacerbations within a year)
4) Explore further treatment e.g. theophylline, oral mucolytic therapy, long term oxygen therapy
Oral prophylactic antibiotic therapy - what is used?
Azithromycin (usually 250 mg 3 times a week)
When might long term oxygen therapy be needed?
= 15 HOURS A DAY
FEV1 below 30% predicted Cyanosis Polycythaemia Peripheral oedema Raised JVP Saturations <92%
–> then do 2 ABGs 3 weeks apart
If Pa02 <7.3kpa or <8kpa + polycythaemia, peripheral oedema, pulmonary hypertension
–> risk assessment (CANNOT SMOKE)
Varenicline mechanism + contraindications
Selective nicotine receptor partial agonist
Avoid if Hx of mental illness as may cause suicidal thoughts. Contraindicated in pregnancy/breastfeeding, under 18 year olds, end-stage renal disease.
Buproprion mechanism + contraindications
Antidepressant
Increases risk of seizures, so contraindicated in epilepsy, alcohol withdrawal, eating disorders or CNS tumours. It is also contraindicated in bipolar disorder, pregnancy/breastfeeding, under 18 year olds, and severe cirrhosis.
Features of a severe exacerbation
Acute confusion. Marked reduction in activities of daily living. Marked breathlessness and tachypnoea. Pursed-lip breathing. Use of accessory muscles at rest. New-onset cyanosis or peripheral oedema.
What oxygen should be given (if no alert card)?
28% Venturi mask at a flow rate of 4 L/min, and aim for an oxygen saturation of 88–92%
Organisms that may cause pulmonary infection in patients with COPD
- Often viral (30%) e.g human rhinovirus
- Haemophilus influenzae (most common)
- Moraxella catarrhalis
- Streptococcus pneumoniae
Investigations for acute COPD exacerbation
• Oxygen saturations
• ABG
• Sputum sample for microscopy and culture (if sputum is purulent)
• Blood cultures (if pyrexial)
Investigations to exclude other diagnoses:
• CXR
• ECG
• Bloods – FBC, U&E, CRP, theophylline level, cardiac enzymes
• CT/CTPA
?echo
Treatment of COPD exacerbation
Increase frequency of bronchodilator use and consider giving via a nebuliser
Give prednisolone 30 mg daily for 5 days
Oral antibiotics ‘if sputum is purulent or there are clinical signs of pneumonia’
Treatment of COPD exacerbation
Oxygen
Increase frequency of bronchodilator use and consider giving via a nebuliser
Give prednisolone 30 mg daily for 5 days
Oral antibiotics ‘if sputum is purulent or there are clinical signs of pneumonia’
May need non-invasive ventilation
How to choose antibiotics for COPD exacerbation
First line = amoxicillin 500mg TDS for 5 days
If amoxicillin allergy = doxycycline 200mg on first day then 100mg OD for a total of 5 days
If contraindicated = clarithromycin 500mg BD for 5 days
If increased risk of resistance = co-amoxiclav 500/125 mg TDS for 5 days.
