Mechanical Ventilation Explained - Ventilator Settings & Modes

Mechanical Ventilation Explained - Ventilator Settings & Modes 

Hello friends, I welcome you to our website, in which we keep bringing new posts every day. And we have brought a new post for you. Which is going to be of great use to you in your life.

    Welcome to another MedCream lecture. We are going to talk about mechanical ventilation. This is meant to be an introduction to the mechanical ventilated. If you've never done mechanical ventilation before we're going to introduce you to the basics so that you can go in and feel really competent about managing a patient on a ventilator. This is often a difficult task because usually these patients are serious, but in reality the basics are quite understandable and we are going through them now. It's a series that's really going to go through a lot of different lectures. We're going to start with the basics right away. The first thing you need to know is you got to know the definitions of some of these things. You've got the patient. It's quite easy. Then you are coming to know about this thing in their mouth. That's the dotrachial tube. We're going to show this a little more later. Then, you've hooked it up to a big machine with a bunch of knobs on it, and dials and outputs this we know as the ET tube. That's the tracheal tube. Then finally you've got the actual ventilator. This is important to know because sometimes people have intubation. This means we put a tube in their mouth because they need airway protection. Sometimes we do this, in other words, because they can't protect their airway. They cannot protect goods, liquids and solids,

    By going down your airway where that stuff shouldn't. Inexplicably because of this, it is also not comfortable. We have to make them unconscious and when we want to make them unconscious, we have to put them on ventilators. This may be one reason we have to do it. The second reason is that they can protect their path is fine but they are not able to breathe on their own. They are having trouble breathing so we try to take them out with the mechanical part of breathing and that's where the ventilator comes in. The way we deliver it is through the endotracheal tube. It is important to know what an endotracheal tube looks like. The basic is largely similar to Ways # Methods. It's a long tube that looks like this. This is the part that connects to the ventilator. This is the part that goes inside the patient. Actually, you'll notice that there's a balloon at the end of that endotracheal tube and the thing that allows you to blow it up is a little thing that goes up, called the pilot balloon. It goes up. Actually, the pilot part comes out and it looks like a little pilot balloon that you can feel what the pressure is. Then there's a small part where you can inject air into it. When it goes down and you intubate someone it goes into their mouth, the chord behind their vocal cords, specifically, and down into the trachea. Vocal cords usually end around right here so it's going into some trachea then usually it branches off. you have left and right main stem bronchus here you have endotracheal tube going

    Below Now, this balloon is inflated here so that the stuff that can make it down here is not past o and go into the lungs. This is called airway protection. After intubating we blow up the balloon here to make sure it happens. Some versions of it still have a little bit of trickery from here as well. Its purpose is to suck secretions that can come up and out and that is called subglottic suction. This is kind of an option. This is the basic anatomy of an endotracheal tube. Of course we just talked about ventilators. It has a bunch of buttons and whistles and things were about to get a bit talky. Going back to our patient. We've got our endotracheal tube. We have got our ventilator. What is the purpose of this ventilator? The purpose of a ventilator is to maintain homeostasis between the fixed gas concentrations we are talking about here, that is, carbon dioxide and oxygen. Oxygen is being poured into the patient and carbon dioxide is being released. For the most part we want to keep them close to normal. There are some exceptions to this. Here's the thing though. There are many different ways to put in air someone. We can say that we are going to put air in someone on the basis of quantity. We're going to put a certain X amount of volume in any one and then let it escape. This is one way to do this. Another way to ventilate someone is by saying we will inflate them to some degree of pressure. We are going to put this ventilator in a certain amount of pressure in the patient and then when the pressure is applied it is going to come back out.

    We can do that. Now, we can do this at a fixed rate. We can do it fast and we can do it slow so in other words, how many breaths per minute. We can also adjust the flow rate. In other words, we can put a certain quantity in but we can get that quantity gradually or we canMight give the quantity very quickly. The other thing we can do is we can decide how much pressure to leave H there at the end when we put in the air and then we can decide how much pressure to go there after pouring the air . In the end, we can decide how much oxygen we want to put in there. How much? We can put in a lot or we can put in a little. Now, just to make it more complicated so you can see where we're going. With that, we can be in the ventilator when the patient gets their breath or we can put the patient in charge of when they want to breathe. . Think about all these different variables. Now, you can quickly see how this happens. There are many different ways you can ventilate someone, and each one of them has a different ventilation method. You may have heard of these before, such as AC or SIMV or pressure support, or CPAP. These are all different methods and we're going to go through some of these modes and show you how to make sense of how it's working. Here is our system. Here, we have got ventilators. Here, we have that tubing that goes down the endotracheal tube goes down into the lungs and we have our balloon here, filled with air to make sure nothing else falls out. We're ventilating our right lung And our left lung. Let's talk about the method of ventilation first.

    This will become important later. The first mode I want to talk about is AC. The way we call it, it's assistive control. It also has another name for continuous mandatory ventilation or CMV. This is the most common method of ventilation you will see, especially on a medicine floor or medicine unit. The key here is that the patient triggers the exit route. How does this happen? Well, the patient breathes in and so there's a negative pressure here, which causes a negative pressure to feel here, on the ventilator. In another way you can understand it by flow, if there is any flow which actually passes here by negative pressure. As soon as the ventilator picks up on that negative pressure, it is going to deliver a specific amount. There's an actual dial on here where you can actually turn the knob to a specific volume or you can just enter it. That volume can be anywhere from 500 cc to 600 cc more commonly. The ideal way to ventilate someone would be about eight milliliters per kilogram, ideal body weight.

    Anyway, whatever the volume is, it's ventilated to deliver that specific volume in AC mode. Now, the patient can trigger it. You can also set the backup mode or rate. what does this mean? For example, if I set the rate to twelve. Because there are twelve, five-second intervals in a minute. That is, every five seconds the ventilator will give one breath to a patient of a specific volume, every five seconds only if the patient does not breathe. If the patient is breathing above twelve then the ventilator will only breathe when the patient triggers it by trying to take one breath in. In other words, if you set the mode to AC, set to a volume and set the rate to twelve, the patient can never breathe less than twelve times per minute. Now you must understand something about this, which is very important. You can remember from chemistry and the equation which says that PV is equal to nRT. In this system the temperature remains constant. R, of course, is always a constant and is constant. The thing you should realize is that pressure is inversely proportional to volume and itself. In other words, as the volume of the gas goes up the pressure decreases, if you have the same amount of gas. However, another way of looking at it is compliance which I will abbreviate as C. Compliance is equal to the change in quantity

    On a change in pressure, which means that if the pressure changes a little bit and the volume changes a lot, you have a very compliant lung. If you don't have very obedient lungs, this is going to take a lot of pressure. Just make a few changes. Here's the thing. The thing is, these set of lungs have a specific compliance and if you're delivering a specific volume to these lungs, you're going to get a specific pressure after you deliver that volume. That can change depending on the pressure compliance. The point of this is that you should have a readout that tells you what the pressure is in that lung so that you know what compliance is. In other words, in this mode of ventilation, you set the title volume and the ventilator will tell you what the pressure is so you are setting the titling volume. You are setting the amount of gas to go into the lungs and based on lung compliance, it will tell you what the pressure is. If lung compliance goes down, you will generally have high pressures. If the lung compliance is too high, in other words, a very obedient lung, your pressure will remain on the lower side.

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