ARDS: Berlin Definition (Nursing)

00:01 I told you it gets more specific than the three criteria I gave you in our first overall framework and here it is.

00:08 Now, when you're looking at this, let me help you break it down.

00:11 There's two categories, they're in the dark headings.

00:14 So, one is within the first week of known clinical insult or new or worsening respiratory symptoms, these things happen; the other one is an impaired oxygenation.

00:26 So when you're thinking about the definition of ARDS, this is what the healthcare team will consider in actually diagnosing this in your patient.

00:34 So, first category, we're looking at bilateral opacities on chest imaging not fully explained by effusions, lobar/lung collapse, or nodules.

00:46 Think back to that chest x-ray. Remember what the normal lung look like, right, got that.

00:51 Then remember what the ARDS lung looked like we talked about those opacities, so check, that's one thing we have, we know that we have opacities on the chest x-ray, but we have to rule out that it was caused by something else.

01:06 So, in order for it to be the syndrome of ARDS, we've got to rule out other possible causes, that's why you see the definition there that says, not fully explained by effusions, lobar/lung collapse, or nodules.

01:19 So the patient's gonna need to be evaluated to make sure those aren't causing those opacities.

01:25 Now, look at the next item, respiratory failure not explained by cardiac failure or fluid overload.

01:32 So you want to make sure that those opacities are on there, we know that they're likely caused by ARDS.

01:38 The patient is in respiratory failure, right, they have increased effort, work of breathing.

01:45 We have to place them on supplemental oxygen and it's not caused by someone who's in CHF or they're just fluid volume overloaded.

01:54 We know that it's another cause, its ARDS.

01:57 Now, the third bullet point in our first category.

02:01 You need an objective assessment, something like an echocardiography.

02:05 So underline that word, echocardiography. This means an echocardiogram.

02:11 You may have seen these on your CHF patients, remember we're making sure that we rule out CHF.

02:18 But in echocardiogram, you're gonna come in and take some pictures, right? Gel on the patient's chest, use the magic wand and get some pictures that talk about the function of the heart.

02:29 How is it contracting? How is it expanding? What's the ejection fraction? Because that's gonna help us exclude things like hydrostatic edema even if there isn't a risk factor.

02:40 So, opacities, ruling out other things like heart failure or fluid volume overload and some type of objective assessment that supports the findings, that's the first category.

02:53 The second category is impaired oxygenation.

02:57 Now, divided into multiple categories, we've got mild, moderate, or severe.

03:03 So, I said multiple but really, it's just three, mild, moderate to severe.

03:09 Now I'm sure you've probably already figured out, but you would prefer to have mild over severe, absolutely.

03:17 Now, these are measured by the PaO2/FiO2 ratio.

03:21 Normally, if they are starting to bunk down to 200-300 because, remember, normal is 300-500, this tells us, hey, we're starting to get into trouble.

03:33 Now, you'll notice that end of that sentence says, with ventilators settings of PEEP or CPAP greater than 5 centimeter of water, so they are very specific.

03:44 This patient in ARDS has to be on a ventilator or on CPAP at certain settings and still you get that PaO2/FiO2 ratio.

03:54 So mild is between 200-300, moderate between 100-200, severe is less than 100.

04:03 Now, don't get caught up in that ratio.

04:05 If you're not familiar with it yet, I'll do a quick review in just a minute, but what I want you to take away from this slide is the definition here it's a continuum, right, they're not exactly clear cut with the patient.

04:19 I know we have very clear numbers, 200-300, 100-200, less than 100.

04:26 But you see there's a big difference. Let's take a look at moderate, that's a range.

04:31 There's a big difference between a PaO2 and FiO2 of 102 and 198, so I don't want you to immediately think of this as black and white, it just gives us a language to communicate with each other, but I'm a lot worse off as a moderate ARDS patient with one of 102 than I would be if I had a PaO2/FiO2 of 198.

05:13 Let me explain. Okay, so let's take a look at that ratio of the PaO2/FiO2.

05:19 You'll probably hear it spoken in practice as the PF ratio.

05:23 Now, we can use this to evaluate the level of impairment of the patient's ability to move oxygen from the lungs to the arteries.

05:32 that's what this tells us, so straight up, if this is new to you, make sure you write yourself a note, that's saying, the ability of the patient to move oxygen from the lungs to the arteries, that's what this number tells us.

05:46 So we also use this PaO2/FiO2 in the Berlin definition of ARDS we just discussed.

05:52 So that's why they take this ratio, they create it and they use that in the Berlin definition.

05:59 Now, if you want more information of exactly how that goes down, go ahead and check out our video series that specifically covers the PaO2/FiO2 ratio.

06:09 Okay, so now we've reviewed the definition of ARDS, we've reviewed the PaO2/FiO2 ratio, now let's look at some of the most common causes of this syndrome.