Created by Amy Fan.
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- Why would a drug that blocks the B2 receptor so that the lungs relax stimulate the B1 receptors in the heart, causing tachycardia?(3 votes)
- B2 Agonists enhance the action of B2 receptors, not block them. B1 and 2 are SNS receptors and cause central dilation and increase cardiac output.(10 votes)
- If there are beta receptors then wouldn't there be alpha receptors, but would the alpha receptors be in the brain?(4 votes)
- There are alpha receptors throughout the body. Alpha1 receptors are mostly found throughout the smooth muscle in the body and help control blood pressure. Alpha2 receptors ARE found in the brain and have a more complex action.(4 votes)
- Why is the treatment medicine the same in asthma and COPD?(0 votes)
- Someone correct me if im wrong, but I think it's because the main thing in both asthma and COPD, there is obstruction in the airway from the excess mucous production. B2 agonists and anticholinergics will both help with this because it dilates the airway, allowing o2 and co2 to pass. Steroids and leukotrienes inhibitors both tackle the inflammatory cascade which causes constriction in the smooth muscle cells (which is part of the inflammatory response). This also promotes dilation in the airway. and since both asthma and COPD both have mucous overproduction - mucous can carry viruses which leads to more infection (thus more inflammation), antibiotics would be good to prescribe to prevent it from getting worse(10 votes)
- so theres pink puffers and blue bloaters?(2 votes)
- With all the emphasis on eliminating the source of irritation to prevent chronic bronchitis from developing or worsening, don't you think it would be beneficial to include some videos on SMOKING CESSATION in this series, especially since smoking was singled out as probably the most common etiology of inhaled irritants and we know that there are many smokers who desire to quit smoking?(1 vote)
- I thought the lumen was the end of an airway?(1 vote)
- Lumen in biology means the center of a tube. It is like saying 'doughnut hole'. We have a lumen in the trachea and other airways where the air travels, a lumen in the intestines where the food travels. In physics, it is a unit of light. :)(1 vote)
- following, how woould the inflation begin at2:22(1 vote)
- Would mucolytics have some benefit in the treatment of chronic bronchitis? I know that it would just be symptom management and not help the underlying process. I just want to make sure that doing so wouldn't be contraindicated.(1 vote)
- In the lesson on chronic bronchitis treatment, it may be helpful to mention that a simple expectorant, like Guaifenesin, my help to expel the excess mucus from the lungs. Thank you for considering my recommendation.
Respectfully, Anthony Stello(1 vote)
-[Voiceover] In chronic bronchitis, the problem basically is that we have irritants which lead to inflammation, which lead to the production of mucus, which leads to all the problems in lung function. Actually let's write that lung function. Things like not getting enough oxygen, not being able to breathe out. If that's our theme then it makes sense to think of it one by one. At each of this point, what can we do to treat it? Irritants first obviously to remove the irritant would be the best. First with irritants of course to remove the source of irritation would always be the best and first thing that should be thought of and I'm drawing a cigarette here. No matter how much I sound like a broken record, quitting smoking is hugely important to chronic bronchitis because it's the only thing that stops the source of the disease from getting worse. Everything else here is just treating symptoms but stopping the smoking actually stops the progression of the disease. I really want to throw that out there as our first thing to think about in treatment and of course other sources of irritants can lead to chronic bronchitis, right. A major source for chronic bronchitis especially in some parts of the world is pollution and this one is very hard to treat especially for one person and you can't stop your city from being polluted. Aside from moving, there's not much that can be done usually. Sometimes there is occupational exposures like things to coal or to asbestos depending on where this person works. Of course we can always promote healthier work environments trying to protect themselves with masks or other things but as of right now these are still very high risk jobs for chronic bronchitis. Of course we can have allergens. The person can have some control over if you know what kind of allergens are irritating, you can try to stop, stay away from that as much as possible. Just decreasing all of these and stop irritating the lungs is the first step to treating chronic bronchitis. Okay, so given that this has already happened, we're treating the symptoms. Inflammation is the body's response to irritants. Then the lungs part of that response makes the muscles in the walls of the lungs spasm and that's how we get the cough and also the airways narrow as part of the inflammation. If we draw a cross section of the airway here, we're looking down the tube like this and usually in a non irritated lung the lumen here, might be about that wide. This is smooth muscle and just different things, layers of the wall, there's glands, there's connective tissue. This is how along usually it looks like but when it's being irritated, its spasms and the lumen get so small like this, it's hard for air to get through. All of these muscles are spasming and the walls are getting thicker like that. In our case, there's going to be some mucus in the lumen's wall clogging it up. One important way to treat this is a ... Write this as a bronchodilator. We already know that broncho first at the lungs, bronchodilator. This basically just opens the airway back up. The bronchodilator helps us go from this to this. Now, there are different classes of drugs that all qualify as a bronchodilator because all that means is it just opens the airway back up. One important class is a beta-2 agonist. An agonist means it activates this receptor. Beta receptors are part of the fight and flight response that our body has and there are beta receptors all over the body including in our hearts and then there are our eyes. During fight and flight, our pupils get bigger so we can see a little better. Of course since we're talking about this right now is also part of the lungs. The lungs, it just opens up the airway like we talked about just now. Another class is the anticholinergics. Instead of agonist, these are antagonists. That just means it goes against what the cholinergics usually do. Now, this is a completely different pathway but it does the same thing of opening up the lumen of the airways, so we can get more breath in and the lung can be less inflamed. Another completely different kind, different class of anti-inflammatory drugs are the steroids and the leukotriene inhibitors. Leukotriene inhibitors. Up here the bronchodilators really just treat the symptom of inflammations. Write that here. The symptom but down here when we bring out the steroids and the leukotriene inhibitors, these are the big guns that actually go to the actual site of the inflammation and stop it there. How inflammation works in our body is that there's a trigger, so T for trigger. It goes to a cascade one leads to another. We have A leading to B, leading to C, leading to D, dot, dot, dot. All the way, the last step is a leukotriene. We've reached the end, inflammation cascade. Inflammation has started and then we keep going. Of course the leukotriene inhibitor is here. Just gets right at the last step, the product of this whole cascade so it tempers down the inflammation. The steroids are earlier, say in step C. The steroids come in and stop the cascade earlier here. Now I put a slash here but do not confuse them for being similar to each other or being interchanged well they're completely different but I had them together here because they both target the cascade of the inflammation and stops it at the route instead of just going for the symptom of it like a bronchodilator. Okay let's keep going with our process here. Now for the mucus, you might imagine that since they cough so much and that must be very uncomfortable. We might give cough suppressants to these people. You probably seen it over the counter, stops you from coughing. It's important to remember that for chronic bronchitis, we do not do the suppressants because that mucus is already there. We want it to come out. Again, we have our airways here and it's coated by, there's too much mucus here and we don't want it. Let me use a blue color because it's kind of a liquid. Okay here's all the mucus and we cough all day long. That's uncomfortable, yes. Imagine if we gave them the suppressant and they no longer cough it up, this would just be full of mucus all clogged up. This would actually be horrible for the patient because the more clogged we are, the more we can have bacteria behind it, we'll have pneumonia, other infections so we really don't want that. As much as it's uncomfortable to cough, unfortunately most of the time for productive coughers, we need to let them keep coughing but we can go through these other treatments to go down on the inflammation. Maybe they won't make as much mucus to try to solve the problem that way. Lastly, we have to deal with the fact that the lungs are not getting enough oxygen, these people are called blue bloaters because they have lower oxygen in their blood because the airways are so narrow and there's mucus so oxygen doesn't get through as well. We might think, okay, let's give them oxygen. Nowadays it's easy enough to do that in the hospital or at home oxygen but I really want to put that in parenthesis because yes, a lot of people get this but in some patients especially very sick patients. We have to be very careful about giving them oxygen and here's why, and here we have to talk about the issue of the breathing drive. I mean you don't have to think about breathing all day long, right? Just because something in your brain automatically tells us to breath. This is there when you're asleep. It's a very powerful drive and it's important to remember that in most people, let's say their O2 level is about this high. Their carbon dioxide level will be about this high, it's going to be lower and that differential is there. Remember the oxygen goes in the blood during a breath and when you breathe out, the CO2 comes out. If you're not breathing, the CO2 goes up and oxygen comes down. If you or I stop breathing, it is the fact that our CO2 would go up. That signals our body in our brain that "Uh-oh we're not breathing" and the breathing drive kicks in. In a person without bronchitis, it is this fact that the CO2 is going up that makes us breathe, that signals our brain, our body that okay we need to keep breathing, once you get that gas out of there. CO2 controls the breathing drive in people who don't have chronic bronchitis. Okay, this is healthy, H for healthy. Let's look at people with chronic bronchitis. What happens is that their O2 level is lower to begin with and their CO2 level is higher than normal like that. The CO2 being high no longer makes them breath, drive them to breath. Is the fact that this O2 is low, that controls our breathing drive. If we give them oxygen here, this can actually take away the breathing drive like giving them too much oxygen. The body will think because it's usually relying on the oxygen to breath. With extra oxygen, that drive might go away and this person going to actually stop breathing especially when they're having a bad episode of chronic bronchitis. Oxygen is used but it can be dangerous and they should be used with caution and this person should be monitored to make sure that they're still breathing. Lastly I just want to mention that if a person has an acute episode just when the disease gets really bad, we will treat them aggressively with steroids, yes but one other we want to add are antibiotics because they might have an infection. If they have it, we have to treat it and they don't, we want to prevent it because the extra mucus during an acute exacerbation can keep the bacteria in the lungs. You really want to get on top of that and make sure that we don't develop pneumonia on top of bad chronic bronchitis. Here in a nutshell are the most common treatments for chronic bronchitis. As you can see most of it is symptomatic which means we don't get rid of the root of the problem. Remember to go back to the beginning. Whatever we can do to reduce the irritation to begin with, would be the best thing for the patient in the long term.