Ventilator Modes and Monitoring (Nursing)

00:01 In this section, we're going to take a look at the modes of ventilation.

00:04 Now, hang with me sometimes this can be confusing when you first learn about it, but I promise you, we're going to walk you through step by step.

00:12 The first mode we're going to talk about is Assist-control.

00:15 When you see it on a chart or in orders, you may see it written as A/C, but it means assist-control.

00:21 The next one is synchronized intermittent mandatory ventilation, which is why we call it SIMV.

00:28 So let's talk about the differences between the two.

00:32 Assist-control is usually used in people who are critically ill.

00:37 So this one is kinder, gentler, does more of the work that SIMV would.

00:43 So we use this with really sick people who need a lot of support, they might have a suppressed or even absent respiratory drive because of medications or illness.

00:53 So assist-control when you think about that, that means the ventilator is doing more of the work than the patient.

01:00 So when it says control, the respiration is fully controlled by the ventilator.

01:05 Now that to me it sounds a little creepy.

01:07 But let me explain it to you. This is really a good thing.

01:11 Remember, this is for a client who is critically ill not able to breathe on their own and how assist-control works is one part.

01:19 It will deliver a set amount of breaths per minute at a set volume.

01:24 Let me give you an example.

01:26 If the ventilator settings were assist-control of 18, that means the ventilator will deliver 18 breaths a minute.

01:34 Now, it's at a certain volume that's also ordered by the physician.

01:37 Remember when we talked about tidal volume? So this patient is going to get 18 breaths a minute at a preset volume.

01:45 Here's the part where it gets really helpful to a patient.

01:48 If they're breathing more than 18 breaths a minute, if they try to take an extra breath, say they want to take 20 or 21 breaths a minute, then the ventilator will kick in and support the patient.

01:59 So say they've got their 18 breaths, they want to take another one, all they have to do is to start to breathe, and the ventilator will deliver the full volume of the breath.

02:10 That's what makes it assist-control.

02:14 Now, there's different types of assist-control.

02:16 We have two different types of ventilation classifications.

02:20 You have assist-control volume-control, right.

02:22 So they're both assist-control.

02:24 It's just the last half, that is different.

02:27 Assist-control volume control, or Assist-control pressure control.

02:32 And this is going to kind of speak to how we put guardrails up for a patient, right? How we keep them safe when they're on assist-control.

02:39 So let's break those down. Let's take a look at them.

02:42 Assist-control volume control is the one that's most commonly used in the initial mode of ventilation.

02:48 So you'll see this most often when a patient is just being initiated or started onto ventilator support.

02:55 Now, it assists every sensed inspiratory effort made by the patient.

02:59 So, again, you know what that happens when a patient starts to take a breath.

03:03 It's going to assist the patient.

03:05 That's the assist-control volume control portion of that.

03:10 Now, assist-control PC that's a little different.

03:14 This is appropriate when peak airway pressures are important.

03:18 So think about a patient who has pretty fragile lungs, right? They've had patients with previous Barotrauma, there's lungs have already been damaged, or maybe even after like a thoracic surgery.

03:29 So this one, we want to watch the pressures really, really closely.

03:33 So, which one will you see, most often when a patient is initially started on a ventilator, if they're going to be on assist control? As A/C VC, you got it.

03:43 This is for somebody who has super friable lungs, and we just want to give them a little extra level of protection, You'd use A/C PC.

03:52 Now, Synchronized intermittent mandatory ventilation (SIMV).

03:57 This is more commonly used in the intensive care units.

04:00 This one, the patient gets to participate in the process in a totally different way. Let me explain.

04:07 So we used to think this was the best for weaning patients off the ventilator.

04:10 There's definitely a lot of other opinions out there.

04:14 But the patient is responsible for partially controlling the breath.

04:18 In SIMV, if they start to take a breath, the ventilator just doesn't kick in and deliver the volume to them.

04:26 They're going to have to work to pull that volume themselves.

04:29 So, if they are SIMV of 18, they would get those 18 breaths but if they wanted anything extra, the patient has to draw that volume in their self.

04:38 So, we commonly use pressure support with this one for obvious reasons.

04:43 Okay, well, maybe it's not that obvious.

04:45 Pressure support is going to help you overcome all of that tubing.

04:50 We've got our patient there on the screen.

04:53 You see that they've got their endotracheal tube and then you see that is connected to the ventilator tubing.

04:58 Well, what's off screen is the whole length of tubing that connects to the ventilator.

05:03 That takes a lot of extra effort to suck all that air through all of that tubing.

05:10 This patients on a ventilator because they're not doing great with breathing.

05:13 Pressure support will help that patient kind of even the odds.

05:18 Kind of keeps an even pressure going so they don't have to work quite as hard.

05:22 But they still do have to pull that volume themself.

05:25 So, that's why an SINV, they often use pressure support.

05:29 I'm going to walk you through some of the key monitoring parameters that we watch when a patient is on a ventilator.

05:35 Now, there's some new abbreviations, but we've got them spelled out for you here.

05:38 And I'll walk you through what they mean.

05:40 Ve means minute ventilation.

05:43 So that means in a 62nd period or a minute, this is going to be the amount of air that's delivered in that minute by the ventilator.

05:52 So when you hear people talking about minute ventilation, that's what they're referring to. The volume of air over a minute.

05:59 Now PIP, is Peak inspiratory pressure.

06:03 This is a number that will be set by the physician that says this is the maximum amount of pressure the patient should experience during breathing in or inspiration.

06:15 Now, Pplat happens right before expiration or breathing out.

06:20 So this is the pressure that's applied through the ventilator.

06:23 And what it does is having that pressure there will help keep those alveoli open.

06:28 Those tiny small airways at the very end of the lung tissue helps to keep them open, because we want to make sure those alveoli don't collapse.

06:37 And if you're on a ventilator, remember, you're in a pretty precarious spot.

06:41 So that's what Pplat is.

06:44 Now before we go on, I just talked to you about three pressures.

06:48 What I want you to do is to pause the video and see if you can remember, all three of those and you can include Pplat, and a definition of each one but do it without looking at your notes.

07:03 Okay, that's it. How many could you remember? This is the best way to study with me as we're walking through it. Because when you pause and recall, You're teaching your brain to remember these things for when you really need them.