Lecture 19 - Chronic Airflow limitation Flashcards
what is asthma?
Chronic infalmmatory disorder of the airways
often associated with atopy
SymptomsL recurrent episodes of wheezing, breathlessness, chest tightness and coughing
Widespread, variable, usually reversible airfow limitations
The allergen can stimilate which two cells in asthama pathophysiology?
mast cell (usually) or macrophage cell
causes mucos production and vasodilation and angiogenesis
What happens to the subepitheliual collagen layer in asthmatics?
Remodelling causes it to thicken
in addition, the infiltration of inflammatory cells causes an increase in mucosal vascularity
What happens to smooth muscle volume in asthamatic remodelling?
increases a lot. - augments the airway hyperresponsiveness
The narrower a luminal diameter..
the high the airflow resistance (der)
FEV1 is affected ___ than FVC in patients with obstructive lung disease
more - FVC can be fully preserved in cases
Why do patients feel breathless with obstructed airways?
here is a change in the “work of breathing” - change in the load
Breathlessness is a recognition of an inappropriate degree of respiratory work for body workload
What are the factors that exacerbate asthma?
Allergens resp. infections pollutants Exercise and hyperventilation weather changes food, additives, drugs emotion
How do you make a diagnosis of asthma?
appropriate clinical setting
need to demonstrate reversible airflow obstruction (peak flow, spirometry - reduced FEV1)
Bronchoprovocation test - measures hyper-reactivity
Targetting the inflammation that causes airway hyperresponsiveness is due using…
anti-inflammatory steroids (usually)
sometimes monoclonal antibodies
Remember asthma treatment is more than just …
pharmacotherapy (although its important)
Asthma medication tries to minimise the underlying pathophysiology - what are all the medication options?
beta 2 agonists
inhaled corticosteroids (preventer)
oral corticosteroids - only for severe asthmatics
combination inhalers
leukotriene receptor antagonists
anti-IgE
clinical effect for corticosteroids is at what dosage?
a very modest amount - point of difference with COPD which needs higher doses
What is COPD
group of disorders characterised by airway inflammation and airflow limitation that is not fully reversible
A progressive condition associated with an abnormal inflammatory response to noxious stimuli (almost always cigarettes)
fully reversible asthma is not COPD
What are the two broad categories of COPD?
Emphysema - loss of airway tissue
Chronic bronchitis - inflammation and speutum production
What are the COPD stats in Australia
3rd leading cause of disease burden in Australia
Fourth leading cause of death in Australian men & 6th in women
nearly 500,000 people in Aus with moderate to severe COPD
mortality of COPD 10-times higher in indigenous Australians
Among principal causes of death, only COPD continues to have a growing death rate
COPD is currently what (in terms of diagnosis)
under-diagnosed
under-recognised
under-treated
COPD is preventable and treatable but largely unknown to health care professionals
smoking is responsible for __ -__% of COPD cases
smoking is responsible for 80-90% of COPD cases
Up to ___% of long-term smokers develop COPD
50%
15-20% develop severe airflow limitation
Inflammation , caused by noxious agents acts in two parts of the lungs, what are they?
Small airway disease - Airway inflammation, airway remodelling
Parenchymal destruction - loss of alveolar attachments, loss of elastic recoil
What are the inflammation damages from COPD?
Mucociliary dysfunction
strutural changes
Airway inflammation
systemic component
Around one thurd of pateints with COPD grow _____from respiratory specimen during stable state
bacteria
Bong hits are bad because?
Temperature of air is much hotter and there are fungi in the (pure) form
There is alot of shared genetic predispositions between COPD and ___ ___
lung cancer - comorbid
What are the non-pharm. and pharm. smoking cessation strategies?
non-pharmacologic:
will power doctor's advice self-help material councelling courses
Pharmacologic:
Nicotine replacement therapy
bupropion (partial agonists of nicotine receptor)
varenicline (partial agonists of nicotine receptor)
true or False
b2 agonists (long-acting) are standard treatment
true
Long-acting anticholinergics are demonstrated to achieve
less dyspnoea
better exercise tolerance
less exacerbations
less mortaility
The only patients that will benefit from inhaled corticosteriods is…
those with frequent exacerbations
higher doses needed than in athsma
risk of pneumonia is increased
Other are other treatment options for COPD?
Theophylline
long erm antibiotics
pulmonary rehabilitation
vaccinations (particularly influenza)
oxygen (only for those with significant resting hypoxia)
