COPD Flashcards
What is the definition of COPD?
COPD is characterised by airflow obstruction… usually PROGRESSIVE, NOT fully REVERSIBLE and does NOT CHANGE markedly over several months. The disease is a CHRONIC INFLAMMATORY response in the airways and lungs to noxious particles or gases, predominantly caused by smoking
what is FEV1/FVC for airflow obstruction?
<0.7
what is the FEV1/FVC post bronchodilator?
still <0.7
what are the classifications of FEV1 is COPD?
≥ 80% Stage 1 Mild* 50–79% Stage 2 – Moderate 30–49% Stage 3 – Severe < 30% Stage 4 – Very severe s0 severity is determined by FEV1
why is it harder to expel air in COPD?
the airways collapse as the elastic tissue is destroyed and the airways are no longer open, so there is high resistance against breathing out
what term d owe use to describe the flow volume loop shape for COPD is the expiratory part?
scolloped
what are the two mechanisms of airflow obstruction in COPD?
small airways disease
and parenchymal destruction
what are the characteristics of small airways disease in COPD?
airway inflammation (inflammatory infiltrates) airway fibrosis (scarring of walls) luminal plugs (hyperplasia of glands and goblet cell metaplasia) increased airway resistance
what are the parenchymal destruction aspects of COPD
loss of alveolar attachments
decrease of elastic recoil
what feature of COPD patients causes them to breath at a higher volume?
dynamic hyperinflation
Why do COPD pts show dynamic hyperinflation?
due to the scolloping of the flow volume curve, they can’t breathe their normal tidal breath at a normal volume, need to do this at a higher volume. So inflate their lungs to breathe. when they do exercise, they have to breathe at even higher lung volumes
what is the V/Q match like in COPD
mismatch
would the values for Tlco and Kco be high or low?
low
is a high pCO2 seen in COPD?
potentially, but remember there is type 1 and type 2 resp failure and so this would mean type 2 resp failure. poor ventilation can give high pCO2
Is pulmonary hypertension seen and why?
yes as the alveoli are obliterated, so there is less oxygenation and hypoxaemia results, so the blood vessels constrict to reduce the V/Q mismatch
what are the signs and symptoms of COPD?
Shortage of breath Cough, phlegm Wheeze Raised respiratory rate Hyperexpansion/barel shaped chest Cyanosis Weight loss ‘cor pulmonale’
who are the pt groups most likely to get COPD?
Old patients, smokers, male predominance
what are the features of a pink puffer?
breathlessness is the predominant problem - they are not cyanosed
weight loss
pursed lips on expiration help to prevent airway collapse
what are the features of blue bloaters?
hypoventilation productive cough cpr pulmonale peripheral oedema barrel chest features of CO2 retention, bounding pulse, warm peripheries, flapping tremor of outstretched hands and maybe confusion
what are the risk factors for COPD?
smoking + passive occupational dust and chemicals pollution genes - alpha 1 antitrypsin deficiency infections socio-economic status age illicit drug smoking
what are the points of the MRC (Medical Research Council) dyspnoea scale?
grade 1: SOB on strenuous exercise
grade 2: SOB hurrying on level or walking up slight hill
grade 3: Walks slower than most people on the level, stops after a mile or so, or stops after 15 minutes walking at own pace
grade 4: Stops for breath after walking 100 yards, or after a few minutes on level ground
grade 5: Too breathless to leave the house, or breathless when dressing/undressing
what are the points covered by the COPD assessment score (CAT)?
Cough Phlegm Chest tightness Breathlessness going up hills/stairs Activity limitation at home Confidence leaving the home Sleep and energy final score (minimum 0, maximum 40) – this is a measure of the overall impact of a patient’s condition on their life.
is lung function a strong predictor of QOL?
no - other factors play a role in QOL
what other treatment option is there apart from drug therapy to help reduce decline?
exercise therapy
