Hi rachel, I can't read your lecturer's mind but maybe this is what he's thinking...both asthma and COPD present clinically with breathlessness or acute exacerbations.
However, asthma usually presents with reversible symptoms and interference with normal activity of various degrees i.e. acute exacerbations of breathlessness +/- wheezing and after medication (short acting beta-2 agonist)will be normal.
COPD on the other hand is generally a partially reversible condition (this is a controversial issue for some doctors if you just mention it. You'll have to specify that the improvement of this disease can only be partially achieved if put on long term medication) thus their symptoms are persistent. But what I think your lecturer wants to hear (maybe) is the salient clinical feature of COPD which is the chronic bronchitis of blue bloaters and the emphysematous pink puffers.
A typical blue bloaters (not always seen) have CO2 retention, the picwickian syndrome (obesity, somnolence, hypoventilate, plethoric/red face), short neck, doesn't look breathless, an abnormal ABG (hypercapnic, hypoxic) & shallow breathing.
The pink puffer does not retain CO2, is usually thin, has a long neck, look really breathless, has a normal/ near normal ABG & pursed lips breathing.
That makes all the difference in my opinion for these 2 conditions.
