COPD - tutorial Flashcards
What does COPD stand for and what does it mean?
What is COPD most commonly associated with in western cultures / UK? And the rest of the world?
Chronic = long term
Obstructive = obstruct airflow
Pulmonary = lungs
Disease
UK = cigarette smoking
e.g. India = cooking over open fired
What are the similarities and differences between asthma and COPD? (in terms of causes and treatments too)
Asthma = allergic reaction, fragile airways can close up as they are hypersensitive, caused by many inflammatory cells that release mediators such as interleukins, treated by bronchodilators or corticosteroids, reversible condition
COPD = also produce mucus, but produce a different portfolio of inflammatory cells that produce different mediators, an irreversible lung condition of airway obstruction
What is the pathology of asthma? Use this image to describe?
Airway constricts - as seen by the folds of the airways around the circumference (epithelium)
Mucus - blocks the lumen
What are the 3 conditions of COPD? Describe the conditions:
Chronic bronchitis - mucus hypersecretion completely blocks up the larger airways
Chronic bronchiolitis - characterised by fibrosis, narrowing of the small airways due to the laying down of fibrotic tissue, fewer alveoli connections
Emphysema - lungs are physically darker in colour and have holes in them, alveoli collapse / destruct due to thinning
What are some treatments for COPD depending on the dominating condition causing their COPD?
Mucolytics appropriate if COPD is largely due to chronic bronchitis
Not much treatment for the other dominating conditions
What is the pathophysiology of COPD?
What is the role of the macrophages, oxidants and proteases normally, and how does continuous cigarette smoking alter these normal functions?
Normally - Macrophages fight the bugs / toxins in the inhaled air, and normally there is a balance between oxidants and antioxidants, and proteases and anti-proteases
With continuous cigarette smoking - the macrophages become more active that produce strong oxidants more frequently, which kill bugs but also end up damaging the lungs. Results in an imbalance between oxidants and antioxidants, and proteases and anti-proteases, as continuous production of oxidants / proteases outweighs those of the antioxidants / anti-proteases
What are some developing treatments for COPD?
Development of anti-proteases to restore the protease and anti-protease balance
65M, diagnosed 5 years ago with COPD as it dehabilitated him (could not exercise etc.), used to smoke a pack (20 cigarettes) a day, started when he was 15 and gave up smoking when he was diagnosed
GP has asked him to take part in a drug trial that is given via inhalation - has a dual action: they take out the neutrophil elastases and MMPs (the proteases)
Prior to the administration of the lung, they will have lung function tests, bronchiolar lavage, CT scanning, cannot resume smoking, and must not have any other diseases
Must take the inhaler 2x daily, correct usage shown by a nurse - 5 follow up sessions over 2 years
Use this info to answer the following questions:
Why do trials only take on people with only one disease?
What are the 2 groups in a trial?
What is a placebo?
To establish cause and effect
Other disease may impact effectiveness of medication or medication may impact other diseases
Control (taking the placebo) and the one taking a drug
Looks like the drug but without the active component
What are the lung function tests performed and why is it necessary to do these on the patient prior to the trial?
Explain the graph / slide below:
Measure FEV1 - to compare how his lung function deteriorates with / without the active drug
2 guys came up with: lung function test at 25 y/o measured their FEV1 and it was marked as their 100%. All following FEV1s in their life would be a comparison to this. Everyone showed a decrease in their lung function, but COPD has a much steeper decline
How would the patient’s lung function tests change with the placebo compared to active drug?
Placebo - slight decline deterioration but more or less following same curve of decline
Active - lesser deterioration, follows a shallower curve of decline in lung function
What is the purpose of a bronchoaleveolar lavage prior to the trial and in the follow up sessions?
What is the purpose of a high resolution CT scan?
Look at protease activity in the lavage, look for decline in proteases (as drug = protease inhibitor)
Look for a change in the number and size of the holes in the lungs that are eaten by the proteases - with the placebo the number and size of holes increase proportionally with time, with the active drug if it is perfect the number and size of holes will remain constant
What are the changes in epithelial cell profile and secretions during chronic bronchitis?
How does smoking affect this?
Chronic bronchitis = characterised by excessive mucus production by goblet cell hyperplasia and hypertrophy of the submucosal glands
Cilia = damaged, therefore cannot move the mucus away from the airways
What is stenosis?
Why do the small airways become obstructed, stenosed and collapsed?
Narrowing or hardening of a tube
Obstructed = by mucus
Stenosed = from fibrosis, laying down of fibrotic tissue
Collapsed = destruction of the alveolar attachments holding the airways open by proteases
What happens to the structure of the lung during emphysema?
What are the 2 types of emphysema?
Degraded by the proteases and oxidants
Lung has functional units into which the airway comes into it and bifurcates, bifurcation occurs in the centre of the acinus
Cigarette smoke comes in via the larger airways and hits the centre of the airways before it bends around the bifurcation where less cirgarette smoke affects the smaller airways - known as centri-acinar
Genetic deficiency of alpha-1 anti-trypsin - as the enzyme is deficient thtoughout the acinus, it affects the whole of the lung equally - known as pan-acinar
