04.04 Ventilator Settings

Hey guys, in this lesson we're going to talk about ventilator settings. So it is important to understand the basic ventilator settings and modes. It is crucial in critical care nursing when you have a ventilated patient. So make sure that you know what the different modes mean, the different settings and that way you're able to provide the appropriate nursing interventions for these patients. So let's go ahead and talk about it. So first of all, indications for a ventilator. I'm sure that most of y'all know why patients need to be on a vent. So these are some of the most common reasons. If a patient is unstable and they're decompensating and they are unable to meet oxygen demands. If they go into acute respiratory failure or adult respiratory distress syndrome, which is also known as ARDS. If they go into a cardiac or respiratory arrest, if they are hemodynamically unstable and quickly decompensating like somebody who is septic and going into shock or if they're having surgery, especially if they're having major invasive surgery, they will be intubated and they will come out on vent and they will stay like that for a few hours. Perfect example of that would be a patient who's undergoing bypass surgery.So when you have a patient who just got intubated or you're assuming care over somebody who has been intubated, you have got to make sure that you assess a few things, always check that ET tube and make sure that you have a patent airway. If not, your patient's not breathing and they could die. So some of the things that you do to check the ET tube is you check the size. For the most part, some ET tube sizes go anywhere from seven and a half to eight. Usually men have a bigger size than women. The basic example that I can give you guys is you don't want a 300-pound man with a size six ET tube. Basically that's going to be too small. It's like having a really small little straw and trying to blow air through it.

It's not going to happen. So you have to make sure they have the appropriate size of ET tube. Hopefully they pick the right one when the patient got intubated. Then you want to check for placement. If you ever hear the term the the ET tube is at 21 at the lip. Basically what that means is if that's my patient's head, that's their eyeball. Here's their nose it's their mouth and an ET tube is inserted. Well, it goes something like this. It's got little markings on it for different centimeters. So if you have 21 at the lip, 21 to 23 is, is for the most part, the most common placement. So if you have 21 at the lip or 21 at the teeth, that's good. Want to keep an eye on it and make sure that it doesn't move.

If I were to have my ET tube 28 at the lip, it means that it's inserted too far and it's probably in the right lung and only inflating that side. So I would have to make sure that I get respiratory to come help me so we can pull this ET tube out. If it was 10 at the lip, then it's not inserted far enough so the patient is not adequately being ventilated. So this would need to be inserted a little further again to about 21 to 23 at the lip after you verify placement. Another thing you want to do is check your securing device. It can either be tape or velcro or a commercial tube holder and basically it kind of wraps around the back of the patient's head and it secures and holds onto that ET tube so that it doesn't fall out.

And then you want to verify placement. You want to make sure that it is in the right spot. This can be done with a chest X-Ray. It can be done by listening to breath sounds or an end-tidal CO2 monitor. And then lastly, you want to check the cuff. You want to make sure that that cuff is inflated and that basically to keep this simple, you can do that, but some ventilators are able to do that. If not, you would do like a leak test. And again, this is more complicated in it's easier if you work with Vents often, the most important thing is you don't want to hear a leak and you want to make sure that your cuff is inflated. So let's go ahead and talk about different ventilator modes. Keep in mind that some hospitals have ventilators that combine a lot of these modes or they are highly advanced with different modes.

These are the most basic ones. So let's go ahead and cover these, in the first one which is the ACVC or the assist control volume control mode. In this mode, the ventilator will deliver a set tidal volume. So if the respirations are set at 12 per minute and the tidal volume is set at 500, the ventilator will guarantee that and will deliver a guaranteed volume of 500 with each ventilated breaths of whatever the event is set to. This is typically used with patients who are unstable and need full ventilatory support. The second mode, It's a pressure control. So here what you're doing is it delivers a predetermined pressure to help inflate the lungs. It may not always get a guaranteed a tidal volume you're more worried with this setting about the pressure needed to make sure that those lungs get inflated.

A good example will be if you have a patient with ARDS, when a patient has ARDS, you don't want the patient to overinflate the lungs because it's already a little constricted. So you're worried more about the pressure so that it doesn't get damaged. And that would be in pressure control. Another setting is the SIMV or the synchronized intermittent mandatory ventilation. So in this particular mode, the vent delivers, it's kind of like the same setting. So if you're delivering a rate of 12 breaths per minute in a tidal volume of 500, the vent will deliver this. But if the patient breathes on their own, the vent will also deliver or will assist the patient with the breathing. This is used with weaning because it'll have like a preset amount that you want. And then again, if the patient spontaneously breaths on their own, it'll go ahead and help them out with that.

With the pressure support mode, this mode is, these two are usually seen together because it's again used for weaning. You can have a pressure support on its own and basically if you were to have pressure support only the ventilator is not set to deliver a certain number of respirations a minute or tidal volume, it is simply there just to assist the patient to overcome the work of breathing. What you need to understand that in this mode that if a patient is not ready to be weaned or cannot spontaneously breathe on their own, they should not be in pressure support mode. They need to be in the assist control mode. And then lastly, we have a bi-level or a by vent mode. This is usually seen in more advanced vents when a conventional vent is no longer working for a patient cause this is more advanced and not all ventilators are able to do this type of mode.

And basically there's a couple different settings like a high and a low setting on this one. You're able to have longer inspiration and shorter expiration or if you want to set it for shorter inspiration and longer expiration, you're able to do this with the bi-level mode. And this just usually helps when you have patients with oxygenation problems where the conventional vent is just not doing the work. So let's go ahead and talk about other ventilator settings. These are usually ordered by the doctor, so you have to make sure that the event is set to the proper settings. The FIO2, that's the amount of oxygen that the patient needs. Some vents go from 40 to 100%. This can be a little lower, but the typical is just 40 to 100%. They need to have a respiratory rate set on them. Again, for the most part, it's 12 to 20 breaths per minute.

The vents need to know the tidal volume to deliver a title volume is the amount of air required to inflate the lungs. Usually it's between six to eight mls per kg. So if I have a patient that weighs 75 kgs, they would have a tidal volume of 450 mls. So what this means is if the tidal volume is accidentally set to 650 mls, my patient is being overinflated. This can cause some damage. And then lastly, you want to set the peep. The is the positive end-expiratory pressure. And this is the pressure needed to keep the alveoli open after expiration. And this is very useful cause it helps to facilitate gas exchange.

And so some nursing considerations when you have a patient on vent, number one would be sedation. Keep in mind that not all patients need to be sedated for the most part, most of the time they do, especially if they're biting the tube or bucking the vent or trying to pull out their ET tube. Yes, you want to start some propofol or some Precedex. But again, you may have a patient who is on a vent and requires no sedation. Usually you may have an order for to do SATs and SBTs and basically this is spontaneous awakening trials where you wean off the sedation a little bit to check their neurological status or SBT spontaneous breathing trials where you basically see if they're breathing on their own, if they're ready to be weaned off the vent, always check to make sure you have a patent airway, listen for breath sounds, suction as needed. You want to make sure that you prevent pneumonia, check that peak airway pressure, the alarms on a vent will go off, especially if your peak airway pressures are getting elevated and basically, you need to keep an eye on this if the number is high. What that means is there's increased pressure to inflate the lungs. It can be something so simple as a patient needs to be suctioned or they have decreased lung compliance and basically their lungs are getting a little stiffer. And so you want to make sure that you keep an eye on the peak airway pressures. And then lastly, of course we are nurses. So we provide holistic care. So you want to turn these people, you want to provide oral care and just basically you have to 100% take care of the patient other needs like nutrition, if they have the OG tube or a peg tube, just address everything. And one last thing that is imperative to understand when you have a patient who is on a ventilator, you have to have ambu bag at the bedside in case something were to happen. Then the vent stops working. You have to make sure you oxygenate that patient. So always have an ambu bag at bedside.So just to recap, make sure that you guys understand the basic modes and settings on a ventilator, because it is crucial in critical care nursing when you have a patient who is intubated, know what nursing interventions to implement, so that you can take care of these patients the right way. So I hope that this little lesson has helped you guys and giving you guys just a basic understanding of the ventilators and the settings and different ventilator modes. Again, I know that it's something that's a little harder, more complex to comprehend, but try to keep it simple and as always, make sure that you guys go out and be your best selves today and happy nursing.