Created by Amy Fan.
- So, I've got a nice little chart here that tells us how to categorize how severe somebody's asthma is. Basically, these three are persistent, as you can see, more than twice a week. Moderate is daily. Severe is bad symptoms every day, sometimes twice a day. So, here we've got severity scale, and this scale I found is actually, we can adapt it very little to make this scale for evaluating how well somebody is treated. So TX is treatment. The goal in treating asthma, since we can't cure it, is to control the symptoms and reduce the number of times. Basically, we're trying to get them towards the intermittent stage. So, basically for someone to be well controlled, the definition is very similar to the definition for intermittent. So, well controlled would be less than two a week and never more than once a day. So, less than or equal to one a day, when they do have their attack. So, here you say it happened once on Wednesday, just once, then this person is okay. Their medication is working. So, next level is, we say this patient is not well controlled. Don't let the colors confuse you. I'm using green here just to match with this row here, but not well controlled is not green, it's not good. So, I'm going to write WC for well controlled, and this one is defined as more than twice per week, or even if they only have it twice a week, more than once per day when they do have it. So, if they have it on Monday, Tuesday, Thursday, Friday, Sunday, that's not well controlled. That's five times a week. Or even if they only have Wednesday and Saturday, say it only happened on these two days, if they have it let's say two times on Wednesday or three times on Saturday, that already pushes them, that puts them in the not well controlled as well. And then, of course, the last two here, that's poorly controlled. We're not even going to distinguish between them. We're just going to write poor. And if you're the physician, the person who is poorly controlled needs to go way up on their meds. The person who is not well controlled also needs to go up on their meds. So, in terms of treatment, first we've got two modes of delivering the drugs. Let's not worry about the drugs for now. Let's talk about how it's delivered. First we have a nebulizer. Let's spell it out, nebulizer. Now, this needs this big machine here, and it has a hose connected to a mask. So, my very crude drawing of a medical mask. The person basically puts this mask on, and the medication gets evaporated into mist in this machine, and it's delivered with oxygen to the person. It takes about 10 minutes. They just sit there with their mask and breathe it in. Now, this machine can be more expensive, and you need electrical wiring for it, and you need to stay in one place, and it takes about 10 minutes. So, those are the drawbacks, but it works very well. Alternatively, I'm sure you've seen people use this. We have the inhaler, which is this L-shaped tube here with an opening and a button on top. This person can push this button, and the medicine squirts out here. Now, the best way to use this is with a spacer, because the medicine needs to travel with air, and then a person puts their head here and inhales this medication. It takes about 30 seconds, at most. So, this is an inhaler. It is relatively cheap. It's small. It can fit in your pocket. So, it can go with the patient anywhere. So, remember for each of these you can use multiple medications with it. It just depends on what's more convenient for the patient. So, in terms of the drugs that we actually put in here, there are a couple of categories. So first, I want to talk about the drugs that decrease the inflammation. Inflammation is your body's natural reaction to something that's bothering it. Unfortunately, with asthma, inflammation gives us all these symptoms. So, we temper down the inflammation with drugs. So, first we've got steroids. Now, steroids in the body, that's naturally produced there, can also fight inflammation, but, obviously, it's not enough, so we give artificial steroids to temper down the inflammation. We've also got leukotriene inhibitors. This is a weird word. It's just a molecule, leukotriene inhibitors. So, basically it stops the leukotriene from having an effect on the body. Now, the reason these two are related has to do with the way the inflammation starts in the body. We have something, a trigger. An A leading to B, leading to C, leading to D, all the way to the end, we make leukotriene. That's the goal of this whole cascade. So, of course, to stop the inflammation we can either get rid of this, or steroids comes in earlier and gets rid of an earlier stage in the cascade. So, both of these drugs have the same goal, which is to decrease the leukotriene, decrease the whole cascade from causing the symptoms. So, that's one big class of drugs. The other one is bronchodilators. Now, broncho is airway, and dilator means increase the diameter or just open it up, because asthma involves the clamping down or closing of the bronchial pathway. Now, within here we have the beta agonists. Beta is a type of receptors in the body, and in the lungs, their job is to open it up. So, literally we relax the smooth muscle, or if this is asthma right now, with all this smooth muscle clamping down, the beta agonist is able to turn that into a nice open airway, with the smooth muscle much more relaxed around here. So, we throw this drug at the beta-2 receptors on the airway through all of our lungs, and they do different things in different parts of the body, but here, we care about bronchodilation. There are other drugs that also do this. For example, we have theophylline, which is a drug that can be toxic to some people, and we have to monitor the levels very carefully, but it basically does the same thing, of relaxing the smooth muscle and giving us a bigger airway. So, treatment can be kind of trial and error, because our goal is just to go in this direction. So, whatever gets us there, whatever combination of drugs, the amount, we just keep going up and keep adding drugs until we get to well controlled, and that is the goal of our long-term treatments for asthma.