Ventilator SETTINGS (PIP?/PEEP? RATE??) for BEGINNERS!

Welcome to Tala Talks NICU. Today we're going over Ventilator 101 Part 2. So today we're going to be talking more about the ventilator settings and what you actually type into the ventilator machines. If you haven't watched the first part, then go back and watch it, otherwise this isn't going to make a lot of sense. And please stick around so that you can get a great picture of my dog who made a sneak appearance later. We divided this video into two parts because we had some sound and video issues with the first half of this talk initially. So it's going to kind of break up into slightly different videos and we really appreciate your feedback about that, so thank you. For the purposes of this video, we're going to only be talking about pressure support ventilation. Eventually we'll go over different forms of ventilation, but let's get the basics down first. So imagine that you were just at a delivery and you intubated a kid and you're wheeling the kid back and the RT, the respiratory therapist, asks you what settings would you like to put into the vent? Even though they probably already know it and they have an idea exactly of what they want to place, but they'll ask you anyway. So today we're going to go over the PIP, the PEEP, I-Time, E-Time, Rate and Pressure Support. To explain this, I'm going to start by drawing a graph. So here we have the x-axis and the y-axis. The y-axis is pressure and the x-axis is time. So obviously as time moves forward, the machine is going to give different amounts of pressure to the baby. So the first thing that we have to determine is what we want our positive end expiratory pressure to be. That is the pressure, if you remember, that the machine gives at the end of the breath, the minimum pressure that it gives to try to make sure that the alveoli stay open. Like we said, it's kind of like the functional residual capacity in a normal lung. So here, let's call that the PEEP, again, positive end expiratory pressure. In neonates, normally we use a PEEP somewhere between 5 and 7 centimeters of water. In this case, let's assume that our PEEP is 5. The next thing that you need to determine is how much PEEP you want to give or the peak inspiratory pressure. This is the maximum air pushed in by the machine. Again, with positive pressure ventilation, that's a positive pressure. So, for example, let's assume that this is our PEEP. And in this case, let's say it's 20 centimeters of water. The PEEP is actually a lot more variable than the PEEP. But ultimately, the PEEP that you want to give will depend on the compliance of the lungs. If the lungs are stiffer, then you're going to need a higher pressure to try to open them up. Whereas if the lungs are a lot more compliant, then you won't have to give such a high PEEP. Like I said, in this case, let's assume our PEEP is 20, which is kind of an average maybe on the lower side PEEP for babies. The next thing you need to decide on your machine is what the rate of breaths that you're giving is going to be. Or how many breaths is the machine going to give in one minute? Babies breathe faster than adults, between 30 to 60 times a minute. So if the rate is 30, then there'll be 30 breaths in a minute or one breath every two seconds. One breath would be taken up by a PEEP and a PIP. So that would be considered one breath. So then we have another breath here, another breath here, and another breath there. So on over the course of a minute. Like I said, if the rate that you set on the machine is 30, then 60 divided by 30 is 2. So each breath will last for two seconds. So that would be the time spent in PEEP plus the time spent in PIP would equal a total of two seconds. If you set the rate at 60, then obviously each full breath would only be one second. So the time spent in PIP is called the I-time or the inspiratory time. And the time spent in PEEP, although we don't use this as often, is called the E-time. So here you see E-time and then I-time. Again, one breath is equal to the E-time plus the I-time. When we breathe normally, we spend a shorter time inhaling or creating a PIP as compared to exhaling or time in PEEP. Similarly, when we use positive pressure ventilation, we also have much shorter I-times as compared to E-times. I don't think I made it obvious enough on this graph, but generally the I-time is much shorter than the E-time. One of the parameters that you type into the vent is the I-time. Obviously, if you also set the rate, then the longer you make your I-time, the shorter your E-time. So if each breath lasts a total of two seconds and your I-time is 0.4 seconds as opposed to 0.3 seconds, then your E-time is going to be proportionally shorter. In reality, I-time is actually dependent on a combination of compliance as well as resistance of the lungs. Generally, the stiffer the lungs, the longer it will take them to fill, so the longer the I-time should be. We pretty much fix the I-time in neonates. So for the tiny ones, the micropremies, our I-time is normally somewhere between 0.3 and 0.35 seconds. For most neonates, we use about 0.35, and if the babies are a lot bigger and they have stiffer lungs, especially, for example, in babies with chronic lung disease, then we would use I-time of 0.4 or even 0.45 seconds. Okay, so like we said already, these are the different parameters that you would type into the machine. The PEEP, the PIP, the I-time, so this is your I-time, this is your E-time, and your overall rate, so how many times you're going into PIP in every minute. Now, let's go back to the first lecture where I talked about oxygenation and ventilation. Remember when I said that oxygenation is dependent on the overall pressure, because it will allow the alveoli and the blood vessels to approximate and therefore have better BQ matching. So on the ventilator, the overall pressure is depicted by the mean airway pressure, which is the area under the curve. So all of this will determine the mean airway pressure. So, if you are on a ventilator and the baby is having issues with oxygenation, what can you do? You want to increase the mean airway pressure. The first thing that you could do is increase the FiO2, at least until you're trying to figure out what's going on. What are other ways, looking at this graph, that you could also increase the area under the curve? So, the first thing that you could do, you could go up on the PIP. And if you think about it, because you spend longer in expiration than in inspiration, so your E-time is longer than your I-time, going up on the PIP is a very effective way to increase the area under the curve. So going up on the PIP is a very effective way to improve your mean airway pressure and therefore your oxygenation. What else could you do? You could also go up on the PIP. Obviously, that will also improve your oxygenation. What else could you do? You could spend a longer time in PIP. So if all of these were slightly wider, then again, that's going to improve the area under the curve, therefore the mean airway pressure, therefore your oxygenation. So increase PIP, increase PIP, increase I-time, and increase FiO2. And we can discuss all of those more later. What I want you to realize from this is imagine that everything stays the same. Your proportion of I-time over E-time stays the same. Say your total cycle is 2 seconds and your I-time is 0.3 seconds. So you've got 1.5 seconds here of E-time. If you kept everything else the same, the PIP and the PEEP, and the proportion of I-time over E-time the same, if you doubled the rate, so instead of having 3 of these going up, we now have 6 of them going up in the same amount of time, and your I-time would drop proportionally, that would not affect the oxygenation, because you would still have exactly the same area under the curve. So realize that changing the rate, if you're keeping the same proportion of I-time and E-time, is not going to affect your oxygenation. So that's oxygenation. FIO2, PEEP, PIP, I-time. Now let's talk about ventilation. What did we say that ventilation was dependent on? What are we trying to do with ventilation? We're trying to get the carbon dioxide from the alveoli outside the lungs. So what's important is the tidal volume, which is the air breathed in and out with each breath, as well as the rate, so how many times a minute you're breathing. So remember this previous graph that we had, and we saw that the tidal volume was dependent not just on the compliance of the curve, but also on the difference in pressure. So here, if your PIP was, let's say that that's 12, and this is 5 as your PEEP, then your tidal volume is going to be the difference between them, so it's going to be that. If your PIP is 20 and your PEEP is 5, then your difference in pressure is going to result in a tidal volume mapping. So you can see from this graph that to increase your tidal volume, therefore improve your ventilation and blow off your CO2, you can go up on the PIP. So can you see how going up on the PIP improves both the oxygenation as well as the ventilation because it's increasing your tidal volume? Also, to improve your tidal volume, though, you can go down on the PEEP. So say our PEEP really was 7. If you take that down to 5, if anything, that's going to improve your tidal volume. But going down on the PEEP, what's that going to do? That would decrease your oxygenation. So generally, again, we do not change the PEEP. We decide how much pressure the baby needs at the end of its expiration to make sure that those alveoli don't collapse. And generally, we'll keep it about the same, whether it's 5 or 6 or 7. If we're really in desperation from an oxygenation standpoint, we might go higher than that. But generally, we're keeping the PEEP the same. So when we go up on the PIP, then we are affecting both the oxygenation as well as the ventilation. What else can we do to affect the ventilation? We can increase the rate because the rate also will allow more of that carbon dioxide to leave the lungs. So I'm going to reiterate this one more time. On a breathing machine, to improve the oxygenation, you can increase the FiO2, increase the PEEP, increase the PIP, or increase the eye time. To improve the ventilation, you need to improve the tidal volume, which you can do by increasing the PIP, decreasing the PEEP, but we don't really want to do that, and then increasing the rate. So all of those are going to improve the ventilation. There's just one more thing that I want to mention with the ventilator. And that is, for the purposes of this, this is again pressure mode because we're typing in pressures here, we are assuming that the baby is not taking any extra breaths by itself. So here, if you set the rate at 30, every two seconds exactly the machine will take a breath. Whereas in reality, we want the machine to be synchronized with the patient. So what we really do is synchronize intermittent mandatory ventilation, which means that if the baby breathes 20 times a minute, even if you set the rate at 30, for those 20 breaths, the machine will recognize when the baby is about to take a breath, and then give it the full PEEP. So in that situation, the baby is not always going to be fighting against the machine. So it might not be exactly two seconds, it could be at one and a half seconds, and then three seconds, but the machine will wait for the baby to take a breath, unless it's lasted too long, and then it will force a breath. So say you set the rate at 30, and the baby is breathing 40 times a minute. So like we said, for 30 of those breaths, the machine is going to give the full PEEP. So if you're breathing 40 times a minute, and the rate is 30, then there's 10 breaths, which the machine is not giving the PEEP to. But if you think about it, if the baby is intubated, and is effectively breathing through a straw, then that's a lot of extra resistance that that baby needs to breathe through. If somebody just intubated you, and just told you to breathe without putting you on a breathing machine, you would eventually tire out. It's much more exhausting to breathe through such a narrow space, versus the decreased resistance of our trachea and lungs and everything. So, for those extra breaths, which are not accounted for by the rate, we type something into the machine called pressure support, which is where when the baby takes a breath, which is not being given the full PEEP, we give just a little bit of extra pressure, just to help get over that resistance in the lungs. So your pressure support could look a little bit like this. So not quite the PEEP, but a few centimetres of pressure higher than the PEEP, just to help the baby get over that little bit of resistance. Different hospitals, different practices, will use pressure support to a different degree. But it's important that we give that to the baby, just so that the baby gets a little bit of effort for their breathing. Again, if the baby wasn't taking any breaths, then the pressure support wouldn't matter. The baby only receives those pressure support breaths when the baby is breathing, and is not receiving the full machine breath. If your rate is 30 times a minute, so that means that each breath... My dog is here. So that's... Yeah, you're famous. So that means that each... Okay, that was a lot of information today. That was basically, you know, all of neonatology in one video. So please look over it. If you do have more questions, then I'll be very happy to answer them. I am going to go into more details about vents and the different modes that can be used, as well as eventually we'll talk about high-frequency ventilation. But otherwise, I really do hope that you learned something. Please remember to like and subscribe and comment below about future topics. Thank you.