COPD Flashcards
what causes COPD
90% is smoking related
other causes can include pollution, fuel smoke
increased susceptibility with alpha1-antitrypsin deficiency
macroscopic changes in COPD lungs
increased mucus secreting goblet cells in mucosa
inflammation of bronchi
pus secretion in lumen
emphysema + narrowing = airway limitation
microscopic changes in copd lungs
inflammatory cell infiltration of bronchial walls
lymphoid follicle production
which airways are usually affected first in copd
small airways
what is the effect of chronic inflammation in copd
scarring, thickening and narrowing of airways
what is emphysema?
abnormal permanent enlargement of air spaces distal to terminal bronchiole with desruction of walls without obvious fibrosis
2 common types of emphysema
centri-acinar emphysema
pan-acinar emphysema
describe centri-acinar emphysema
distension and destruction around respiratory bronchioles with preservation of more distal alveolar ducts
describe pan-acinar emphysema
distention and destruction affecting entire acinus - forms bullae
what is the effect of emphysema on lung function
airflow limitation and V/Q mismatch
explain how COPD happens
chronic inflammation causes thickening of walls, causing scarring and narrow of airways
emphysema causes destruction of alveoli causing V/Q mismatch and further airflow limitation. loss of elasticity also causes premature airway collapse and air trapping
chronic mucus secretion also leads to blocking of airways
all these factors lead to obstruction of airway, hyperinflation of lungs, hypoxaemia, hypercapnia
why does polycythaemia happen in copd?
renal hypoperfusion/hypoxia causes fluid retention and increased erythrocyte production
why does cigarette smoking cause COPD
cigarette smoke causes increase in neutrophil granulocyte production. these cells produce proteases and elastases which damage the air walls
why does alpha1-antitrypsin deficiency cause copd
alpha-1-antitrypsin is an important antiprotease, without which the activity of proteases will cause progressive damage to the air ways
what is cor pulmonale
pulmonary hypertension
signs of cor pulmonale
pulmonary edema
Right ventricular hypertrophy
peripheral edema
severe cor pulmonale -
ascites
hepatomegaly
elevated JVP
xray findings in a copd patient
usually normal but can see
hyperinflation
flattened diaphragm
level 1 - 5 on the MRS dyspnea scale
1 = sob only on strenuous exertion 2= sob on hills and hurried level walking 3 = walks slower than most people, sob after ~15 mins walking at own pace 4= stops for breah after ~100 yards or few minutes on level ground 5 = too breathless to leave the house or when undressing
what is bupropion?
nicotine acetylcholine receptor antagonist - reduces smoking cravings
what can be prescribed in smoking cessation programs?
nicotine replacement patches
buproprion
varenicline
what can be prescribed to reduced the pleasureable effects of smoking?
varenicline
what is the commonly prescribed mucolytic drug?
carbocysteine
investigations in exacerbation of COPD
find out if infective or not
CXR sputum culture ECG Blood cultures ABG PEF meter
differential diagnoses in someone with known COPD presenting with increasing breathlessness, increasing cough, fever,
(I)E of COPD asthma heart failure lung cancer pneumonia PE airway obstruction
extrapulmonary symptoms/signs of COPD
cor pulmonale - heart failure/pulmn H/T
osteoporosis
polycythaemia
metabolic disorders - weight loss/muscle wasting
