COPD Flashcards
What is COPD characterized by?
Airflow obstruction that is usually progressive and not fully reversible, doesn’t change markedly over months
What are the 2 diseases encompassed in COPD?
- Chronic bronchitis
- Emphysema
(can have either or both)
What characterizes Emphysema?
Destruction of the terminal bronchioles and distal airspaces leads to loss of alveolar SA
What occurs as a result of the destruction of terminal bronchioles and distal airpspaces in emphysema?
Destruction of tissues…
a) removes scaffolding support of small airways which makes them collapse leading to obstruction
b) increases compliance: reducing lung recoil leading to hyperinflation
Is emphysema an obstructive or restrictive disease and why?
Obstructive due to the loss of tissue scaffolding and subsequent collapsing of smaller airways
What are bullae and when do they form?
Permanent air filled spaces within lung parenchyma with a thin/poorly defined wall formed during emphysema
What are the 2 types of emphysema?
- Centrilobular: primarily upper lobes, occurs with loss of resp. bronchioles in proximal portion of acinus with sparing of distal alveoli
- Panlobular: Involves all lung fields, especially the bases
What characterizes chronic bronchitis?
Inflammation in larger airways leads to chronic mucus hyper-secretion, this causes re-modelling and narrowing of airways
What are 3 symptoms of chronic bronchitis?
- Chronic productive cough
- Frequent infections (damage to mucociliary escalator)
- Progressive breathlessness and increasing frequent exacerbations
What is the main cause of COPD, and what are 3 other causes?
- Smoking
- Alpha-1-antitrypsin deficiency: no inhibitor of trypsin means neutrophil elastase is constantly activated causing persistent lung tissue damage
- Occupational exposure
- pollution
Explain the MRC Dyspnoea score
Grade of breathlessness
1: not troubled except during hard exercise
2. Short of breath when hurrying or walking up slight hill
3. walks slower than contemporaries on level ground due to breathlessness
4. Stops for breath after walking 100m or so
5. Too breathless to leave house, dress, etc
What are 5 signs of COPD?
- Pursed lips: increases the pressure in airways to force them open
- Tachypnoea
- Use of accessory muscles
- Hyperinflation: air trapping
- May have wheeze or quiet breath sounds
As the disease advances what 3 things are likely to occur?
- CO2 retention
- Cyanosis
- R heart failure
What is the predicted percentage of FEV1 in mild, moderate and severe airflow obstruction?
Mild: 50-80% predicted
Moderate: 30-49% predicted
Severe: <30% predicted
How would you diagnose COPD?
Combination of suggestive symptoms and signs with at least mild airflow obstruction (spirometry)
Compare the differences between COPD and asthma on the basis of these factors:
Smoker
Symptoms <65
Chronic productive cough
Breathlessness
Nighttime waking with breathlessness or wheeze
Diurnal or day-day variability of symptoms
Smokers: COPD - nearly all, asthma - possible
Symptoms <65: COPD - rare, asthma often
Chronic productive cough: COPD - common, asthma - uncommon
Breathlessness: COPD - persistent/agressive, asthma - variable
Nighttime waking with breathlessness or wheeze: COPD - common, asthma - uncommon
Diurnal or day-day variability of symptoms: COPD - uncommon, asthma - common
What investigations could you do for COPD?
- Chest-x ray; not diagnostic
- High resolution CT scan: can assess emphysema destruction
- Arterial blood gases: assess resp failure
- alpha1 anti-trypsin for younger patients
Compare Emphysema and chronic bronchitis on the basis of these factors;
Area destroyed
V/Q
Level of hypoxia
Other symptom:
Area destroyed: Emphysema parenchyma, chronic bronchitis-small airway inflammation
VQ: emphysema; matched, chronic bronchitis; mis-matched
Level of Hypoxia: Emphysema; mild hypoxia, chronic bronchitis; severe hypoxia and hypercarbia
Other symptom: emphysema; cachexia, chronic bronchitis; pulmonary hypertension and cor pulmonale
List 6 factors part of the MDT approach - COPD care bundle
- smoking cessation support
- pulmonary rehab
- bronchodilators
- anti-muscarinics
- steroids
- mucolytics
Name the pros and cons of one bronchodilator that can be used
Salbutamol: B2 agonist
Bronchodilator but may activate B2 receptors in the heart causing adverse side effects; tachycardia, palpitations, hypokalemia
Name the pros and cons of one anti-muscarinic that can be used
Impratropium: reduces bronchoconstriction and mucus secretion
Adverse effects: dry mouth and cough, sore throat, pharyngitis, upper resp tract infections
+Other ANTI parasympathetic responses; urinary difficulty, constipation, AF, etc.
Name an example of a mucolytic
Carbocysteine (clears mucus)
What are the pros and cons of corticosteroids?
Pros: reduce inflammation
Cons: thin skin, bruising, osteoporosis, diabetes (increase insulin resistance), weight gain, mental disturbance
What is the key message around drug therapy for COPD?
Can improve symptoms but not cure
How would you manage the acute exacerbations for COPD?
- O2 saturation with O2 therapy is aimed to be 88-92%
- Use nebulised bronchodilators
- Antibiotics if suspected infection
- Ventilation if arterial blood gases don’t improve
- Oral or IV steroids
What are the criteria for offering a patient long-term oxygen therapy?
- If pO2 is consistently blow 7.3 kPa
- Patient’s must be non-smokers
- patient’s must be retaining high levels of CO2
What are 2 therapies that can be offered if the COPD is very advanced
- Lung volume reduction; reduces hyperinflation
2. Long-term oxygen therapy
What are 3 things patients can do for self-management
Get help, recognize if their symptoms worsen, rescue pack-antibiotic/oral steroids
What are some benefits of pulmonary rehab?
- Nutritional counselling
- Exercise training - increased exercise tolerance
- Increased knowledge on self-management and lung condition
- Increased independence in daily function
- breathing strategies
- Psychological counselling and/or group support
