Emphysema treatment

Voiceover: In talking about treating emphysema I think the most important thing, the first thing to talk about is to stop smoking. Out of all the therapies this is the only one that will stop the disease from getting any worse. Since smoking can cause emphysema it's like the first way to get out of the hole is to stop digging it any further, right? Stop smoking that's the first one. In terms of drug therapies they can't reverse what's already been done but it can help with the symptoms and I think it's important to divide it between chronic therapies and acute. Chronic is what a patient would take everyday to maintain their status. Acute is when once in a while emphysema can have exacerbations. They can get a whole lot sicker really quickly and we use a different combination of drugs to get them through that acute disease. An important first class of drugs in the chronic maintenance therapy I think are the bronchodilators. Broncho which refers to the airways. Dilator just refers to the fact that these drugs get your airways to open up like a tube that becomes bigger in diameter. If this is our airway tree like this. Branching and branching off. If I take a cut right here so that we can look across this tube it will look something like this. You have the outside and you have the lumen which just means the inside where the air goes through. In here in the walls of the airway it's actually full of smooth muscle. Smooth muscle are not skeletal muscles. We can't control it with our mind but a combination of things in the body like the nervous system and other conditions affect how tightly wound this muscle is. Smooth muscle. The way that I've drawn it here is actually pretty tightly wound. Look how small this lumen is becoming as the muscle tightens. The muscles contract this way to squeeze down on that lumen. The bronchodilators can open up that airway. The lumen we'll draw it as this big because the muscles around it have relaxed a little bit. It's not so tightly wound anymore. See how much room this gives us in the middle. That will allow a lot more air through it than this little lumen back here. The bronchodilator is actually an umbrella term and includes several classes of drugs but all of them share the effect of opening up that airway. The first class of bronchodilators I want to mention are the beta2-agonists. They stimulate the beta2 receptors. Beta2 receptors are part of the sympathetic nervous system. This is the fight or flight response. As part of it it wants to open up your lungs a little bit. Stimulating the beta2 receptors will do just that. One drug you might have heard of in this class would be albuterol and actually the drugs in this class all end with something -rol. it's an easy way to recognize and just from the names that can make no sense in English. The second class of drugs would be the anticholinergics which are ... Anti so they are antagonists which means it turns off the receptor. This involves different receptors on the airways but the effect is the same. In these drugs their names often end in opium and it has nothing to do with the drug opium. It's just a coincidence like that. Broncholators open up the airway but one of the reasons that they're constricted in the first place is because there's too much inflation. The next class I want to talk about are the leukotriene inhibitor. Again, what are these words? They mean nothing in English. Leukotriene is an important player in the cascade that leads to inflammation. For example, in the cascade if we have A leading to B leading to C, leading to D and so on, eventually at least to leukotrienes which here I'll just write LT for leukotriene. This is the goal of the inflammation cascade. I want to get here to cause inflammation which includes restricting the airway and other things. Obviously by inhibiting leukotrienes we toned down in the inflammation. It gets rid of some of the mucous and the constriction in our lungs that we're fighting in the first place. Especially in emphysema, toning down the inflammation is a big deal because inflammation is how we get so much neuotrophils and elastase. Toning down the inflammation by inhibiting some of the leukotriene helps the disease from getting worse as quickly. A lot of emphysema patients can take these chronic medications everyday but unfortunately sometimes they can still develop an exacerbation or a flare where the compensation system they have in place is not working all of a sudden and you get much sicker really quickly. Our goal here is short term, get them back to their baseline. One of the first things we give them are antibiotics. Antibiotics. Sometimes when they come to the hospital they already have an infection but if they don't we still give them antibiotics for prophylaxis which just means that disease hasn't happened yet. We're giving it to prevent it, prevention just in case. Because when they're having an exacerbation their ability to deal with infection goes down. As a general rule in the body anytime you have blockage or things not moving the way they should there can be infection behind it because our body is constantly clearing things out of our system. In emphysema for example if you have these dilated airways, these walls and the air is trapped back here in exacerbation that gets even worse. Imagine all these collapsed airways. Now all the things moving out are not moving, are not working great in emphysema to begin with and now they're even worse. We have a dramatic increase in the possibility of having an infection. There's bacteria in the lungs all the time and the lungs try to clear them. Now we're spinning out of control in this flare and the usual system to clear this bacteria is not working well so we give them antibiotics. Just because they have a pneumonia or some other infection on top of everything right now that would be horrible. We want to do everything we can to prevent that. Antibiotics. The next thing in terms of inflammation, we got to give them a huge dose or something. We got to pull out the big guns here. We want to give them some steroids. Steroids are the universal tempering down the inflammation big guns. We have our cascade again. A leading to B to C to D dot, dot, dot. Eventually to leukotrienes. Steroids work much earlier in the cascade. Let's say it works in step C. We usually give them a pretty big dose and the cascade stops right here. Now that's good for preventing inflammation but since this is a cascade and it's connected so D is also not working. All the other things that branch off of C and D, the other arms of the immune system which inflammation is part of are also not working. With all these things out of commission yes,our inflammation goes down. That's our goal. At the same time it also takes down the immune system. They're immune compromised during their steroids treatment. Immune system down. This makes the antibiotics even more necessary but also this is why we try to not give people steroids for a long, long time. This is like an emergency save of our cars running down the hill. We need to stop it first and then we can think about how to get back on track. That's steroids and another thing. This person can't breathe or having trouble getting air in and out. You come to the hospital. It might seem kind of logical to put them on oxygen, right? In the hospital we put oxygen on people at the job if they had anytime they have breathing problems. I'm gonna put a question mark here by oxygen because this is actually kind of tricky in emphysema patients. To explain that let's talk about the respiratory drive. Respiratory drive is a combination of mechanisms in the body that make you breathe. You notice that you don't have to think about breathing all day long. That's because between your brain and the nervous system, your lungs there's a system in place to make you breathe. Now usually let's say you're supposed to have this much oxygen. This is O2. And you're only supposed to have this much carbon dioxide. When you breathe carbon dioxide is going out. It's going out and oxygen is what you want to take in. Usually the body is very sensitive to these levels exactly where each one is. Usually the brain is programmed in such a way that if our CO2 goes up this is what stimulates us to breathe. Our respiratory center is more centered on extra, having extra CO2. Emphysema is an obstructive disease, right? We always have too much CO2 and since that's chronic the body is smart, it learns after a while that this patient is just gonna have a little more CO2 than usual. Look at this new dotted line. That's our new normal. We also have a little bit less of oxygen because our lungs are so inflated it's hard to take in more air. This is our new O2. These are new CO2. Now since our CO2 is always above that line stimulating us to breathe, the body is like okay, I get it. I'm gonna change my signal. In emphysema patients the lack of oxygen here this level is actually what drives them to breathe. The respiratory drive has shifted from CO2 driven to O2 driven. They need to constantly be reminded that they lack oxygen to breathe. In our patient with an O2 heavy respiratory drive if you give them oxygen what happens? That oxygen goes up and we lose our respiratory drive. Ironically giving them oxygen can decrease their drive to breathe and that's the last thing you want in somebody who's having an emergency with breathing. Also the body chemistry and pH it's all used to having a little more CO2 than usual. Suddenly giving them oxygen can actually knock this system off balance. It has to be given with caution. If somebody is given oxygen their breathing has to be monitored and making sure that they're still breathing and really, if they really lose that respiratory drive their machines with masks they can take over that drive and make sure that people breathe. This is a quick overview of some of the drugs that we use to treat emphysema whether it be everyday or acutely, but most of all they have to stop smoking. If smoking's what caused their emphysema stop now before it gets worse and if they got emphysema through another way then definitely stop smoking to reduce the number of flares they have and to lessen the burden on the lungs and to stop digging further in this hole.