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)
If someone has a post-bronchodilator FEV1/FVC of less than 0.7, is this enough to diagnose COPD?
No because;
1) If they showed a 12% or greater response in the ratio after the bronchodilator, then it suggests asthma
2) Other causes should be considered in those who do not have the typical symptoms or risk factors for COPD (especially old people)
If someone has a post-bronchodilator FEV1/FVC of greater than 0.7, does this rule out COPD?
No as COPD should still be considered in young people with typical symptoms and risk factors, but who have a FEV1/FVC score of greater than 0.7
How can we grade the severity of airway obstruction?
We do this in those whose post-bronchodilator FEV1/FVC ratio is less than 0.7.
We then assess airway obstruction according to the reduction in FEV1 compared to expected reference values (based on age, sex, height and ethnicity).
This is known as GOLD stage 1-4
What is GOLD stage 1?
This is MILD airway obstruction.
FEV1 is 80% of predicted value or higher
Remember that we only GOLD stage someone when there post-bronchodilator FEV1/FVC ratio is less than 0.7
What is GOLD stage 2?
This is MODERATE airway obstruction.
FEV1 is 50-79% of predicted value
Remember that we only GOLD stage someone when there post-bronchodilator FEV1/FVC ratio is less than 0.7
What is GOLD stage 3?
This is SEVERE airway obstruction.
FEV1 is 30-49% of predicted value
Remember that we only GOLD stage someone when there post-bronchodilator FEV1/FVC ratio is less than 0.7
What is GOLD stage 4?
This is VERY SEVERE airway obstruction.
FEV1 is less than 30% of predicted value or FEV1 is less than 50% but with respiratory failure as well
Remember that we only GOLD stage someone when there post-bronchodilator FEV1/FVC ratio is less than 0.7
What does GOLD stand for in the context of airway obstruction?
Global Strategy for Obstructive Lung Disease
When should you perform spirometry in someone with COPD?
It should not be a routine thing.
Instead it should be performed
- At diagnosis
- If diagnosis is reconsidered
- Monitoring of disease severity and progression
What is the MRC scale used for? What is its full name?
It is used to assess the impact of someones breathlessness (dyspnoea).
It is called the Medical Research Council (MRC) dyspnoea scale.
How many grades are there of the MRC dyspnoea scale? Which is worst, which is best?
5 grades.
Grade 1 is best
Grade 5 is worst
What is grade 1 on the MRC dyspnoea scale?
Breathless on strenuous exercise
What is grade 2 on the MRC dyspnoea scale?
Breathless on walking up hill
What is grade 3 on the MRC dyspnoea scale?
Breathless that slows walking on the flat
What is grade 4 on the MRC dyspnoea scale?
Stop to catch their breath after walking 100 metres on the flat
What is grade 5 on the MRC dyspnoea scale?
Unable to leave the house due to breathlessness.
If a person has examination findings of COPD, but does not smoke, and is under the age of 40, what should you consider? How can you elicit this in the history?
Consider alpha-1-antitrypsin deficiency.
Ask about family history of lung and liver disease.
What is cor pulmonale?
Cor pulmonale is right heart failure secondary to lung disease, and is caused by pulmonary hypertension as a consequence of hypoxia.
What are the clinical signs of cor pulmonale?
- Peripheral oedema.
- Raised jugular venous pressure.
- Systolic parasternal heave.
- A loud pulmonary second heart sound (over the second left intercostal space).
- Hepatomegaly.
What is polycythemia? Why is it seen in COPD?
It is when there is an increased amount of haemoglobin.
It is seen in COPD as it is the bodies normal response to hypoxia, as it tries to compensate.
What is the most common type of organism to cause an exacerbation of COPD?
Rhinovirus
Why can someone with a COPD exacerbation report confusion as a symptom?
Because they are increasingly hypoxic, and increasingly hypercapnic.
What are some DDx for COPD? Why?
- Asthma (dyspnoea, reduced exercise tolerance, wheeze)
- Bronchiectasis (increased sputum, frequent chest infections, coarse crackles)
- Heart failure (dyspnoea, pulmonary oedema)
- Lung cancer (persistent cough, weight loss)
- Interstitial Lung Disease (asbestosis, sarcoidosis)
- Anaemia (chronic fatigue)
- Tuberculosis (persistent cough and breathlessness)
- Cystic Fibrosis
- Upper airway obstruction (tracheal tumour)
What are some DDx for COPD exacerbations?
- Pneumonia
- PE
- Pneumothorax
- Acute heart failure
- Pleural effusion
- Cardiac Ischaemia or arrhythmia
- Lung cancer
- Upper airway obstruction
What is asbestosis? What are the symptoms?
Asbestosis is long term inflammation and scarring of the lungs due to asbestos fibers.
Symptoms may include shortness of breath, cough, wheezing, and chest tightness.
What is sarcoidosis? Which organs does it effect? What are the main symptoms?
Sarcoidosis is a chronic granulomatous disorder of unknown aetiology, commonly affecting the lungs, skin, and eyes. It is characterised by accumulation of lymphocytes and macrophages and the formation of non-caseating granulomas in the lungs and other organs. Although lungs and lymph nodes are involved in more than 90% of patients, virtually any organ can be involved.
Main symptoms include cough, dyspnoea
and chronic fatigue.
What should all COPD patients be offered as part of long term management?
- Smoking cessation courses
- Pneumococcal vacine
- Annual flu jab
What is the first drug you offer someone with COPD for long-term management?
SABA (ex. salbutamol or terbultaline)
OR
SAMA (ex. ipratropium bromide)
What is the second line drug you offer someone with COPD for long-term management?
This depends on whether they have asthmatic or steroid responsive features.
If NO, then give a combined LABA + LAMA.
If YES, then give a combined LABA + ICS. If this doesn’t work, then give a combined inhaler of LABA, LAMA and an ICS.
What are “Anoro Ellipta”, “Ultibro Breezhaler” and “DuaKlir Genuair” examples of?
LABA + LAMA combined inhalers
What are “Fostair“, “Symbicort” and “Seretide” examples of?
LABA + ICS combined inhalers
What are “Trimbo” and “Trelegy Ellipta” examples of?
Combined LABA, LAMA and ICS combination inhalers
If the first and second line inhalers do not work for controlling COPD, what other treatment options are there?
- Nebulisers
- Oral theophylline
- Oral mucolytic therapy to break down sputum (ex. carboncisteine)
- Long term prophylactic antibiotics
- Long term oxygen therapy at home
What class of drug is carbocisteine? Why might it be given in COPD?
It is a mucolytic drug, meaning it breaks down sputum.
Why may a smoker not be allowed long-term oxygen therapy?
Because oxygen is highly flammable, so when it is given to those who smoke, there is a large risk of a significant fire.
How can you tell whether someone is retaining CO2 acutely or chronically?
By looking at the bicarbonate levels.
If its high, then the body is compensating for the acidosis, therefore CO2 is chronically retained.
If its low (it may still be higher than normal, but not enough to control pH), then the body hasn’t had chance to compensate yet, therefore it suggests the CO2 is acutely retained.
On an ABG, what does low pO2 indicate?
Hypoxia and respiratory failure
What does type 1 respiratory failure look like on an ABG?
As its type 1, there is only 1 of the 2 p’s that are abnormal.
- Normal pCO2
- Low pO2
What is the cause of type 1 respiratory failure? Why is pCO2 and pO2 the way that they are?
It is when there is a ventilation/perfusion (V/Q) mismatch. This means that the volume of air flowing in and out of the lungs is not matched with the flow of blood to the lung tissue.
As a result of the VQ mismatch, PaO2 falls and PaCO2 rises. The rise in PaCO2 rapidly triggers an increase in a patient’s overall alveolar ventilation, which corrects the PaCO2 but not the PaO2 due to the different shape of the CO2 and O2 dissociation curves.
Examples include;
- Reduced ventilation and normal perfusion (e.g. pulmonary oedema, bronchoconstriction)
Reduced perfusion with normal ventilation (e.g. pulmonary embolism)
What does a type 2 respiratory failure look like on an ABG?
As its type 2, both of the 2 p’s are abnormal
- High pCO2
- Low pO2
What is the cause of type 2 respiratory failure?
It occurs as a result of alveolar hypoventilation. This occurs for a number of reasons;
- Increased resistance as a result of airway obstruction (e.g. COPD).
- Reduced compliance of the lung tissue/chest wall (e.g. pneumonia, rib fractures, obesity).
- Reduced strength of the respiratory muscles (e.g. Guillain-Barré, motor neurone disease).
- Drugs acting on the respiratory centre reducing overall ventilation (e.g. opiates).
If someone is having a suspected COPD exacerbations, which investigations will you want to perform?
- ABGs to see how much oxygen to give, and assess whether they need ventilating
- CXR to look for pneumonia or other pathologies
- ECG to look for arrythmias and rule out heart failure
- FBC to look for infection
- U&Es to check electrolyes
- Sputum culture is infection is suspected
- Blood culture if you suspect sepsis
Why do you need to be careful with oxygen therapy in someone with COPD?
This is because too much oxygen in someone that is prone to retaining CO2 can increase the amount of CO2 that they actually retain
What are venturi masks?
They are specific masks that are dessigned to give a specific percentage of oxygen (ie. 24%, 28%, 31%, 35%, 40%, 60%)
What oxygen sats should you aim for in someone with COPD if they retain CO2? How can you tell if they are retaining CO2?
Aim for 88-92%.
On an ABG, this is normally about 8kPa for pO2
You can tell if they are retaining CO2 as there CO2 is likely high on the ABG, and you know its chronic if the bicarbonate levels are high
What oxygen sats should you aim for in someone with COPD if they do not retain CO2?
Aim for normal. Therefore anything greater than 94%
If someone has COPD, and are a chronic retainer of CO2, should you give oxygen in the case of an emergency exacerbation?
Yes. However, you should check their ABGs after 10 minutes, and try to bring down the amount of oxygen given as much as possible, but enough so that their sats are between 88-92%
How can COPD exacerbations be managed at home?
COPD patients should be given a steroid pack to keep at home in case of an exacerbation.
They should take
- 30mg Prednisolone once daily for 2 weeks
- Their regular inhalers or home nebulisers
- Antibiotics if evidence of infection
How are COPD exacerbations managed in the hospital?
- High dose Oxygen (which you then titrate down quickly with help from ABGs)
- Nebulised bronchodilators
- Steroids (30mg prednisolone or 200mg hydrocortisone)
- Antibiotics if evenidence of infection
- Physiotherapy can help clear excess sputum
What other options are available to manage COPD exacerbations if it is severe?
- IV aminophylline
- Non-invasive ventilation (NIV)
- Intubation and ventilation with admission to intensive care
- Doxapram can be used as a respiratory stimulant where NIV or intubation is not appropriate
How is non-invasive ventilation delievered?
ie. Which device?
Bilateral positive airway pressure (BiPAP)
How does BiPAP work?
It involves a cycle of high and low pressure to correspond to the patients inspiration and expiration.
IPAP (inspiratory positive airway pressure) is the pressure during inspiration. This is where air is forced into the lungs.
EPAP (expiratory positive airway pressure) is the pressure during expiration. This provides some pressure during expiration so that the airways don’t collapse and it helps air to escape the lungs in patients with obstructive lung disease.
When is BiPAP used?
BiPAP is used where there is type 2 respiratory failure, typically due to COPD.
The criteria for initiating BiPAP is when there is Respiratory acidosis (pH < 7.35, PaCO2 >6) despite adequate medical treatment.
The decision to initiate it would be made by a registrar or above.
When is BiPAP not suitable?
Main contraindications are
- Untreated pneumothorax
- Structural abnormaility or pathology affecting the face, airway or GI tract
What should be done before starting someone on BiPAP?
Patients should have a chest xray prior to NIV to exclude pneumothorax where this does not cause a delay.
What should be in place before starting someone on BiPAP?
A plan should be in place in case the NIV fails so that everyone agrees whether the patient should proceed to intubuation and ventilation and ICU or whether palliative care is more appropriate.
How do you monitor the effectiveness of BiPAP?
You should repeat ABGs every 1 hour until they are stable, and then every 4 hours.
If unstable, the IPAP is increased by 2-5 cm increments (usually starts at around 20cm) until the acidosis resolves
What is CPAP?
This stands for continuous positive airway pressure.
It provides continuous air being blown into the lungs that keeps the airways expanded so that air can more easily travel in and out. It is used to maintain the patient’s airway in conditions where it is prone to collapse.
When should CPAP be used?
Main indications are:
- Obstructive sleep apnoea
- Congestive cardiac failure
- Acute pulmonary oedema
What are the complications of COPD?
- Reduced quality of life
- Increased morbidity and mortality
- Depression and Anxiety
- Cor pulmonale
- Frequent chest infections
- Polycythaemia
- Respiratory failure
- Pneumothorax
- Lung cancer
- Muscle wasting and cachexia
Why are pneumothoraxs a complication of COPD?
This is due to abnormal lung parenchyma and formation of bulla.
Why can COPD cause muscle wasting and cachexia?
It is realtively unclear but thought to be due to a number of factors
- Effects of the disease (increased breathlessness, therefore requiring more energy)
- Increased nutrional requirements
- Psychological factors
- Muscle wasting from decreased exercise tolerence
- typically affects low socio-economic individuals, who have a poor health status anyway
