COPD Flashcards
What is COPD?
Characterised by an airflow obstruction which is:
Progressive in severity
Not fully reversible
Does not change markedly over several months
Umbrella term for chronic bronchitis, emphysema and chronic asthma.
What are the systemic effects of COPD?
Weight loss
Skeletal muscle dysfunction
Cardiovascular disease
Osteoporosis
Depression and fatigue
Cancer
What is normal airway clearance:
Airways lined by cells which produce mucus and cilia which continually beat
Mucus traps dust particles and bacteria
The cilia move the mucus along until is reaches the throat and we swallow it or cough
It’s a defence mechanism
What happens to ‘normal’ airway clearance in COPD patients?
COPD and bronchiectasis excess mucus is produced
Mucus is thicker and stickier
The cilia are unable to beat as the mucus traps it
- a lot of COPD patients are/were smokers - smoking paralyses the cilia
All of this means:
Dust and bacteria stay trapped in the airways
Mucus builds up and provides a warm moist environment for bacteria to grow
Infections can develop = chest infections are common
What is bronchitis?
Chronic disease of the lungs where the bronchi become inflamed
What happens to those who have bronchitis? Symptoms?
The inflammation causes more mucus to be produced which narrows the airway and makes breathing more difficult
Clearly this is difficult as well
Wheezing is very common especially after coughing - bc inflamed airways may narrow for short periods of time, also reduces amount of air that enters the lungs
What must a patient have for it to be confirmed as bronchitis?
Airways must be inflamed
Airways must be narrower, with less space for sputum to get through
May feel unwell, tired and unable to cough
What is emphysema?
Condition where the alveoli of the lungs become inflamed and lose their natural elasticity
They over expand and lose their ability to fill up and contract properly
Consequence of emphysema, what happens?
As air fills up in these sacs some will rupture and become one sac, therefore reducing the surface area for the exchange of oxygen and carbon dioxide
When you breathe out, the trapped air cannot be released and breathing becomes more and more difficult
Can become overinflated due to the trapped air.
What is asthma?
Common disease in the uk
An episodic increase in airway obstruction caused by various stimuli resulting in increased airway resistance
What does asthma cause?symtpoms?
Is it reversible?
Inflammation and bronchoconstriction
Symptoms: breathlessness, wheeze, tightness in the chest
Airways are sensitive - become irritated and narrow
Reduced airflow through the airways
Normally is reversible - use inhalers, antibiotics etc.. to return to ‘normal’
But it can become chronic with some fixed airway damage (eg. Inflammation) and therefore comes under the COPD umbrella.
What are the causes of COPD?
Cigarette smoking (90%)
Significant smoking history, 20 pack years or more (1 pack a day for 20 years)
Occupational exposure - coal miners for eg.
Alpha-1 anti trypsin deficiency - genetic link, this is a protein.
*therefore important to remember that in some cases it is not always due to smoking
Social deprivation - correlation with this.
How do we diagnose COPD?
Detailed patient history
Clinical signs - breathlessness on exertion
Cough, increased sputum, risk factors and rule out other causes
Use spirometer for diagnosis, categorising severity and monitor progression
Use chest x-ray to see if clear clinical signs/anything else to be aware of.
Classification
Early disease -
Often few symptoms
Morning cough (smokers cough) - doesn’t limit ADL’s, chest infections in the winter, breathlessness when exercising vigorously
Clinical examination may be normal eg auscultation although spirometry may be reduced
Classification
Moderate disease -
Range of respiratory symptoms
Cough, wheeze, SOB with moderate exertion
Clinical examination may reveal wheeze, barrel chest, flattened diaphragm on CXR
Classification
Severe disease -
Severe symtpoms
Cyanosis, significant weight loss, raised, peripheral oedema
Overuse of accessory muscles
Treatment for COPD
Smoking cessation - 4x more likely to quit with help, advice and nicotine replacement
Stop smoking services are widely available
Stopping smoking will help slow the progression of the disease
Educate them as much as possible as to why it is so important to stop!
Medication for COPD
Inhalers
Steroids and antibiotics
Mucolytics - help breakdown sputum
Flu and pneumonia vaccines - essential for these patients to keep on top of having these
Pulmonary rehab -
This is just as important as taking their meds
It involves:
Exercise and education
Self management
Diet
Lifestyle modifications
Will all help to reduce admissions and air recovery time post exacerbation
Pathophysiology of COPD -
Exposure to irritant - tobacco smoke, air pollution, industrial chemicals etc
Inflammatory response - stimulate immune system to activate neutrophils, macrophages, lymphocytes in the bronchial walls
These cells release pro inflammatory cytokines and proteases.
Cytokines are like alarm signals that tell the immune system to start fighting
Proteases are enzymes which help digest proteins to clear out damaged cells
Repeated inflammatory response leads to an imbalance in cytokines and proteases and healthy lung tissue begins to get damaged.
Pathophysiology of COPD, airway changes that can become permanent:
Mucosal swelling -
Inflammatory response causes swelling of the bronchial lining, thickening airway walls and narrowing lumen
Pathophysiology of COPD, airway changes that can become permanent:
Mucus hypersecretion -
Goblet cells increase in mucus production. Excess mucus can obstruct airways, impede cilia function
Pathophysiology of COPD, airway changes that can become permanent
Airway remodelling -
Fibrosis (scarring) of the airway walls, lead to further airflow limitation
Damage to alveoli can lead to loss of elasticity of the lungs
What happens to the diaphragm in COPD patients?
Diaphragm becomes flattened and cannot work as effectively
This increases their WOB - it is harder to take a breath in
Due to increased effort, other muscles have to take over the work such as accessory muscles
* costs them a lot more to breath - use much more O2.
