COPD: Diagnosis (Nursing)

00:00 Now how do we diagnose COPD? Well we're going to get a really complete history of symptoms from the patient. We might do some pulmonary function test that gives us specific numbers on how well the patient's able to breathe. We also might look at a CAT scan or a chest x-ray. Now how do we look at this progressive decline? Well we talked about pulmonary function test now you see it in there with a clip on their nose and they have that mouthpiece in their mouth and it's attached to a piece of equipment. So, a pulmonary function test, these are breathing tests that they perform before and after a bronchodilator. So, they will do the test then they'll give patient a bronchodilator that's inhaled and now they'll figure out if the airflow limitation is present and/or partially or fully reversible. Remember that's a criteria we talked about earlier. So, we're looking at pulmonary function test. You do them first then you give the patient an inhaled bronchodilator then you measure again. That will help us know if the airflow limitation is present and if it's partially or fully reversible with the bronchodilator. Now spirometry measures the ratio of the amount of forced expiratory volume in 1 second and that's forced vital capacity. So you divide the forced expiratory volume divided by the forced vital capacity, that will give us a percentage. So that's what we're looking at, that percentage number. So in a pulmonary function test, we're going to end up with that percentage that gives us an indication of the patient's overall status. So, FEV divided by FVC gives us a percentage. A baseline is important and then we consistently check in back with the patient to see how they're progressing. Are they getting better or they go into that anticipated progressive decline that we're trying to prevent. Now, a CAT scan or a chest x-ray are 2 examples of imaging that we use when diagnosing COPD. A chest x-ray will help us rule out other diseases like maybe the patient has lung cancer or bronchiectasis, maybe pleural disease or interstitial lung disease or even heart failure. So, this patient's having shortness of breath, those are other things that we would consider as differential diagnosis and we want to rule them out. Chest x-ray would help that. That also help us identify complications of COPD so we want to make sure that do they have a pneumonia or not, do they have a pneumothorax and air in there that has caused collapse of the lungs or then heart failure. So, chest x-ray can help us rule out other causes or it might help us identify complications of COPD. You know that some of the things are the same in both lists that's why it's never just a one test and we know that's what it is. You have to look at all the pieces of information to put together the puzzle to figure out the underlying cause of the patient's respiratory problems. Now, ABGs and COPD, what would you expect? Well, usually you'll see a mild to moderate COPD, usually shows moderate hypoxemia without any hypercapnia. Now if we didn't use those words, what does hypoxemia mean? Hypo means low, emia is in the blood. So we're looking at ox in the middle, that's oxygen. So low oxygen in the blood without hyperelevated capnia, meaning CO2.

03:27 So with mild to moderate COPD, we normally see moderate low oxygen without elevated CO2.

03:37 Now as COPD progresses, you're more likely to see an elevated CO2 level which we call hypercapnia. Now, ABGs are often worse with an exacerbation, right, with exertion. So the patient's just had a lot of activity then it's going to be worse if they've had an exacerbation of COPD, those are also going to be worse. But it's always a good idea because ABGs only show you what was going on at that exact moment that you drew that arterial blood gas sample, that's what the ABG tells you. So good idea to look at trends. Do you have other values? Do you have trends of before and after treatment? Those are critically important things to help you put that whole puzzle together.