10. COPD Flashcards
Are the following 3 statements true in COPD?
- Treatable?
- Curable?
- Preventable?
- Treatable - yes
- Curable - no
- Preventable - yes
What conditions does COPD encompass?
Mainly emphysema and chronic bronchitis, but also arguable chronic asthma
What is emphysema?
It is the loss of parenchymal lung texture
What is chronic bronchitits?
Chronic bronchitis is a clinical term referring to cough and sputum production for at least 3 months in each of 2 consecutive years.
What is the difference between asthma and COPD?
Asthma and COPD are both obstructive airway conditions caused by inflammation. However in asthma, the obstructive is reversible, unlike in COPD. In addition, inflammation is mainly caused by eosinophils in asthma, whereas in COPD neutrophils are involved.
What are the two types of exacerbations that can occur in COPD?
- Infective
- Non-infective
What is an infective exacerbation of COPD?
Exacerbations are acute episodes of worsening COPD symptoms (such as increased breathlessness, cough and sputum) which are beyond normal day-to-day variations.
They are often triggered by bacterial infections and these are called infective exacerbations.
What is a non-infective exacerbation of COPD?
Exacerbations are acute episodes of worsening COPD symptoms (such as increased breathlessness, cough and sputum) which are beyond normal day-to-day variations
Non-infective exacerbations encompasses everything else other than bacterial infections (therefore viral infections would cause a non-infective exacerbation).
What clinical signs/symptoms will differentiate an infective exacerbation of COPD to a non-infective exacerbation of COPD?
Viral (ie. non infective) causes muscle ache, lethargy, no change to sputum colour and no fever, unlike for infective exacerbations.
What are the main pathophysiological changes that occur to the lungs in COPD?
- Narrowing and remodelling of airways
- Increased number of goblet cells
- Enlargement of mucus-secreting glands of the central airways
- Alveolar loss
- Vascular bed changes leading to pulmonary hypertension
What is causing the changes that are seen in COPD?
Overview, key cells involved, what is amplify the effect of chronic inflammation?
It is the host response to inhaled stimuli (tobacco, environmental fumes etc.) generates an inflammatory response.
Activated macrophages, neutrophils, and leukocytes are the core cells in this process.
Oxidative stress and an excess of proteases amplify the effects of chronic inflammation.
What is the most common risk factor for COPD? What percentage of cases are caused by it?
Tobacco Smoking - 90% of cases are associated with it
What are the risk factors for COPD?
- Tobacco Smoking
- Risk of COPD also increases with weed smoking as well
- Passive smoking also contributes to development of COPD - Occupational Exposure
- Ex. coal, grains, silica, welding fumes, isocyanates, polycyclic aromatic hydrocarbons.
- About 20% of cases have associated occupational exposure - Air Pollution
- Same with the polycyclic aromatic hydrocarbons
- However here, its not because you have burned it yourself, its because everyone else is in the city - Genetics
- This is less common
- Alpha-1-antitrypsin deficiency is the main one. It typically presents in younger people (age <45) - Lung development
- Factors affecting lung growth and development in-utero (materal smoking, preterm birth, low birth weight etc.)
- Factors affecting lung growth and development in childhood (severe respiratory tract infection, passive smoking) - Asthma
- One study has shown that having asthma increases your risk of COPD by 12 times
What are polycyclic aromatic hydrocarbons?
They are found naturally in coal, crude oil and gasoline. They are therefore produced when coal, oil, gas, wood, garbage, and tobacco are burned.
They are a risk factor for development of COPD
What are the cardinal signs and symptoms of COPD?
Hint: 3 cardinal symptoms plus 1 other one extracted in the history
- Cough
- Shortness of breath (dyspnoea)
- Sputum production
- Exposure to risk factors
How is the cough in COPD?
- Initially its a morning cough
- It becomes constant as the disease progresses
- It is usually productive, with sputum quality changing with exacerbations / infections
What are the features of the dyspnoea in COPD?
- Initially it is a result of exercise
- But can progress to dyspnoea at rest as the disease progresses
- It can get that bad that patients have difficulty speaking in full sentences
What are the features of sputum production in COPD?
- Any pattern of chronic sputum production may indicate COPD.
- They normally have white sputum that they produce every morning. This is the normal response to smoking (as it is normally smoking that causes COPD, this is normally seen)
- If the sputum changes colour, then it indicates an infection, which may cause an infective exacerbation of their COPD.
In an OSCE situation, what immediate clues could direct you towards thinking they have COPD?
- Tar stained fingers
- Inhalers
- Sputum pot
- Tripod position
Aside from the cardinal ones, what are the signs and symptoms of COPD?
- ‘Tripod position’ (sat down and lent forwards to open their lungs up)
- Tar-staining of fingers (from tar not nicotine)
- Pursed lips (helps them to breathe)
- Barrel Chest (hyperinflation of the chest due to air trapping coz of incomplete expiration. It presents as reduced lateral and increased vertical chest expansions)
- Hyper-resonance on percussion (caused by hyperinflation)
- On auscultation, there is poor air movement (due to loss of lung elasticity and tissue breakdown), distant breath sounds, wheezing and coarse crackles
Based of the history alone, when should you suspect COPD?
Anyone over the age of 45 with a risk factor and any of the three cardinal symptoms
NEED TO KNOW CARDINAL SYMPTOMS (cough, dyspnoea and sputum production)
What can you look for in the history of someone when you suspect COPD?
PC
- Breathlessness (which may wake them up at night)
- Cough
- Sputum production
- Peripheral oedeme (consider cor pulmonale)
- Weight loss, anorexia, fatigue
- Reduced exercise tolerance
HPC:
- Symptoms getting worse over time (breathlessness, exercise tolerence, peripheral oedema, cough)
PMSH:
- Previous exacerbations of COPD
- Asthma
- Frequent lower respiratory tract infections
- Anxiety and depression
- Cardiovascular disease and metabolic syndrome
- Lung or liver disease
- Osteoporosis
SH:
- Smoker (tobacco, weed, passive smoker)
- Occupational exposures
FM:
- Lung or liver disease (consider alpha-1 antitrypsin deficiency)
If someone comes in with chest pain, should you suspect COPD?
Not really, so you should put in under less likely
If someone presents with haemoptysis, should you suspect COPD?
No, so you should put it less likely (very very unlikely)
What is haemoptysis?
It is when you cough up blood of origin from the respiratory tract below the larynx.
Why is osteoporosis a complication of COPD?
The risk factors of developing osteoporosis include
- tobacco smoking
- systemic inflammation,
- vitamin D deficiency
- use of oral or inhaled corticosteroids (ICSs)
Therefore someone with COPD has a range of risk factors for it.
What would you look for in a respiratory examination for someone who you suspect has COPD
- Cachexia
- Cyanosis
- pursed lips breathing
- Raised JVP
- Use of accessory muscles
- Hyperinflation of the chest
- Wheeze and/or crackles on auscultation of the chest
- Peripheral Oedema
- Check for Cor Pulmonale
In someone who you suspect COPD, you notice clubbing, does this increase or decrease the likelihood of it being COPD?
Decrease as COPD does NOT cause clubbing
Aside from examining someone who you suspect has COPD, what else should you do whilst in the ‘examination’ stage of the consultation
Calculate BMI
How do you calculate BMI?
(Height in m)2
What further investigations would you do in someone who you suspect of having COPD? Why?
- Chest Xray
- It helps to exclude other causes (lung cancer, bronchiectasis, TB, heart failure)
- If they have COPD, they may have hyperinflation, which can be seen on a CXR - Full blood count
- Indentifies anaemia or polycyaemia. - Spirometry
- Measure post-bronchodilator spirometry to confirm the diagnosis of COPD
How do you see hyperinflation on a CXR?
You see this by the number of anterior ribs present over the lungs. Normally, you should only see 6/7, however if they have hyperinflation, it is more than this.
What DDxs to COPD can be picked up on a CXR?
- Bronchiectasis
- Lung cancer
- Tuberculosis
- Heart failure
Why might someone with COPD have polycyaemia? What is it?
Polycyaemia is a raised haemoglobin. It occurs as a response to chronic hypoxia
Aside from the ones that need to be performed, what additional further investigations can be performed in someone you suspect of having COPD? Why?
- Sputum culture
- If it is purulent and persistant
- Most common organism in someone with COPD is haemophilus influenzae - Serial home peak flow measurements
- This is to exclude asthma as a possible diagnosis - ECG and serum BNP
- This is if caridac disease or pulmonary hypertension is suspected
- Depending on the results, an Echocardiogram may also be indicated therefore - CT Thorax
- Indicated if symptoms are disproportionate to spirometry measurements
- Indicated if another diagnosis (lung cancer, fibrosis, bronchiectasis) is suspected
- Indicated in an abnormality identified on the CXR needs further investigation - Serum alpha-1-antitrypsin
- Consider testing it in those with early onset of symptoms, minimal smoking or a positive family history of liver or lung disease - BMI
- This is as a baseline to check later for any weight gain (ex. steroid use) or weight loss (ex. cancer or severe COPD) - Transfer factor for carbon monoxide (TLCO)
- This is decreased in COPD
- Can give an indication about the severity of the disease
- May be increased in other conditions such as asthma
What does purulent mean?
Containing pus
What is bronchiectasis?
Bronchiectasis is the permanent dilation of bronchi due to the destruction of the elastic and muscular components of the bronchial wall. It is often caused as a consequence of recurrent and/or severe infections secondary to an underlying disorder
How should spirometry be performed when trying to diagnose COPD in an individual?
- Perform spirometry as normal, trying to get a FEV1/FVC ratio
- Then give them a short acting bronchodilator (ex. 400 mcg salbutamol)
- Wait 15-20 minutes
- Repeat the spirometry.
What is airway obstruction defined as on spirometry?
A post-bronchodilator ratio of FEV1/FVC of less than 0.7
In order for COPD to be diagnosed, what does the spirometry need to show?
A post-bronchodilator FEV1/FVC of less than 0.7 with no / little response to the bronchodilator (less than a 12% improvement, otherwise it would be asthma)
