COPD Flashcards
(33 cards)
What is COPD?
Common disease characterised by airflow obstruction which is progressive and not fully reversible. The airflow limitation is associated with abnormal inflammatory response of the lungs to noxious particles or gases
Why is it important to know if patients with COPD are CO2 retainers?
Respiratory drive is normally largely initiated by PaCO2 but in COPD, hypoxia can be a strong driving force, which can therefore be reduced if hypoxia is corrected. This means their target sats will be 88-92%.
What ratio would you expect to see in FEV1/FVC in someone with an obstructive lung disorder such as asthma or COPD?
<0.7
How do we categorise the severity of COPD based on the FEV1 % predicted?
> 80% FEV1 = mild
50-79% FEV1 = moderate
30-49% FEV1 = severe
<30% FEV1 = very severe
COPD is the 4th leading cause of death. Is the prevalence of disease expected to rise or fall?
Rise
Most patients with COPD are diagnosed after what age?
> 35
COPD is closely linked with levels of? (social)
deprivation
What is the biggest risk factor for developing COPD?
smoking
Other than smoking, what other risk factors are there for COPD?
air pollution occupational exposure to dust, fumes and chemicals age - more common as you age asthma - overlaps low socioeconomic status alpha antitrypsin deficiency recurrent childhood respiratory infections genes
2 key pathological changes in COPD?
small airways disease
- airways inflamed
- airway fibrosis
- increased airway resistance
Parenchymal destruction
- damage to alveoli and airways which decreases
chronic bronchitis refers to inflammation of the bronchi which is defined as a chronic productive cough for how long?
3 months for 2 consecutive years
In COPD, which immune cells are seen infiltrating the airways?
neutrophils
When there is chronic bronchitis, what happens in the airways? (3)
- Goblet cell hyperplasia
- Mucus hyper secretion
- Chronic inflammation and fibrosis leading to narrower airways
What is emphysema?
permanent dilation of the airspaces distal to the terminal bronchioles
What is the effect of enlarged air spaces in the lungs?
reduced are for gas exchange and leads to chronic hypoxia
In COPD, inflammatory processes lead to the production of proteases by inflammatory cells. What do these proteases do and what is the effect?
protease causes the destruction of elastase which is important in the structural integrity of the alveoli. when this is destroyed, the alveoli can collapse and dilate and bull form.
what is cor pulmonale? what is the most common cause of cor pulmonate in the developed world?
right ventricular impairment secondary to pulmonary disease. most common cause is COPD.
what vascular changes can we see in COPD?
thicker artery walls poor V/Q mismatch low PaO2 poor ventilation may give high pCO2 obliteration and vasoconstriction gives pulmonary hypertension
clinical features of COPD
symptoms
- chronic cough - usually productive
- sputum production
- breathlessness
- frequent episodes of bronchitis
- wheeze
signs
- dyspnoea
- pursed lip breathing
- wheeze
- coarse crackles
- weight loss
- hyper expansion of the lungs- downward displacement of the liver
signs of cor pulmonale?
peripheral oedema
left parasternal heave
raised JVP
hepatomegaly
what is the treatment for an acute exacerbation of COPD?
bronchodilator given as nebuliser (salbutamol)
oxygen therapy used cautiously
corticosteroids: prednisolone
antibiotics for pneumonia
non-invasive ventilation for hospitalised
how do we diagnose COPD?
suspected clinically and confirmed using spirometry
Describe the MRC dyspnoea scale from 1-5
- 1 = SOB on marked exertion
- 2 = SOB on hills
- 3 = Slow or stop on flat ground
- 4 = Exercise tolerance 100-200 yards on flat
- 5 = Housebound or SOB on minor
A patient comes into clinic complaining of a cough and wheeze. The patient is 14 and finds he is waking up at night wheezing and short of breath. You give him a peak flow diary to record over 2 weeks and it shows marked diurnal variation. What do you think is the problem?
Asthma
