Initial Injury and Inflammation – Exudative Phase (Nursing)

00:01 So let's talk about the first of the three phases, the injury or exudative face.

00:06 Now, remember there's an underlying cause of this inflammatory response that's going on in this phase.

00:12 So, what do you remember pause, reflect.

00:16 Stop and think about what were those categories? What's the most common cause of ARDS? Right, Sepsis.

00:24 Good deal.

00:25 Now, there is four other boxes on that page.

00:28 See if you can picture them.

00:31 Take a quick minute and try and write yourself some notes in the margin by training your brain by forcing it to remember your encoding information in a very efficient manner.

00:42 Okay, so we talked about the underlying cause those events, those five categories with sepsis being the most common.

00:50 Now, we're going to divide those up into direct injury to the lungs and then you see something outside of the lungs.

00:57 So, do me a favor and write in the term indirect.

01:00 Yeah, right above that box.

01:02 It says something outside of the lungs, write the word indirect.

01:06 That's what you're likely to see in the literature.

01:08 But I didn't think it was very clear.

01:10 So, I always try to think about direct injury to the lungs then something that happens outside of the lungs or indirect injury.

01:18 Okay, so you're with me.

01:19 Starting at the top where in the injury or exudative phase the first phase or stage of ARDS.

01:27 You have one of those five events happen right up there within a week or when your patient starts having respiratory issues.

01:33 That's the top box.

01:35 So we're going to divide them into direct injury to the lungs or indirect entry to the lungs, which is something outside of the lungs.

01:44 Now, I want to talk about direct injury to the lungs first.

01:48 So let's follow that trail first.

01:51 Here's just some examples of what direct injury could be, Severe Pneumonia.

01:56 Remember severe pneumonia means likely you've got a lot of lobes involved in here, right? So I've got pneumonia and infection and multiple lobes of the lungs.

02:07 Also, an inhaled toxic substance, you breathe it in straight to the lungs and it does damage to the lungs.

02:15 Example, I always think about this is a home fire, my two godsons lost their grandparents who were young active lawyers.

02:24 Not from burn damage, but because they inhaled so many toxic fumes when the home was on fire.

02:30 It was the damage to their lungs that caused them to die.

02:34 So, when you're thinking about ARDS, you know direct injury could be sewn as a really bad pneumonia or they have inhaled a toxic substance something like an example would be a house fire.

02:47 But any toxic substance inhaled right into the lungs put your patient at risk for developing ARDS.

02:54 So, what happens? The event, direct injury, then the inflammatory responders arrived in the lungs.

03:00 That's good because when those lungs take a hit, your body tries to respond to repair things.

03:06 So, that's how inflammatory responders get to the lungs indirect injury.

03:12 You've got the injury right there.

03:13 Then they're going to respond in your lungs.

03:16 Let's move over to the other side of the column and talk about when it's an indirect injury.

03:21 Now, this is where sepsis which we know is the most common cause of ARDS.

03:25 This is where it's one example, pancreatitis.

03:29 Don't let that catch you on a nursing school exam.

03:32 Pancreatitis is an indirect cause of ARDS.

03:36 Also, a massive blood transfusion.

03:39 So, we know from history, we know from demographics and studying patients, these patients that have these experiences sepsis, pancreatitis, massive blood transfusion.

03:49 These are considered indirect injuries to the lungs.

03:53 And that patients are at risk for developing ARDS.

03:56 But look at where my notes all come together, right? All we're talking about is how do these inflammatory responders make it to the lungs? Well, there's a little bit different pathway for the direct injury and there is from the indirect injury.

04:13 Let me explain.

04:14 But at the end of the day, the inflammatory responders are present in the lungs in a really, really big way.

04:22 If it's a direct injury to the lungs, the cytokines are released by the alveolar macrophages.

04:30 We know those right, because there's three types of cells and the alveoli type l, type ll and the macropages.

04:37 Good.

04:38 So that's their job, macrophages are phagocytic.

04:42 They're phagocytic, they're part of your immune system, and that's why they release the cytokines.

04:48 So, if a patient has direct injury to the lungs, massive pneumonia, inhaled something toxic, the macrophages that live in that alveolar area are going to release those inflammatory responders called cytokines.

05:02 But what about the ones that have sepsis or these other areas that are indirect lung injury.

05:09 Those are cytokines are delivered by the blood stream.

05:13 Remember how intimate and close the capillaries are with alveolar.

05:17 Yes, that's because you need that really tight and close interaction in order for CO2 and O2 to be exchanged.

05:25 So when you have sepsis, there are plenty of cytokines running around in that bloodstream, that's how the body has responded and they are delivered through the lungs through the bloodstream.

05:36 Okay, so same process.

05:38 We've got inflammatory responders cytokines arriving in the lungs, some come from the macrophages if it's direct injury.

05:46 Others come by a bloodstream if it's an indirect injury.

05:51 So let's go over that one more time.

05:53 I wanted you to see a macrophage right up close.

05:58 Because I wanted to hit this point one more time to make sure you're studying along with me.

06:02 Remember cytokines are released in the lungs either by the alveolar macrophages because the patient had direct lung injury or more commonly they arrived via the bloodstream due to sepsis.

06:16 Keeping in mind, sepsis is the most common cause of ARDS.

06:21 Now, I've got a chart up here.

06:23 You may not be super impressed by charts, but I just wanted one place where I could summarize everything for you regarding direct and indirect injury.

06:32 Now look.

06:33 On this chart, we're talking about the type of initial injury.

06:37 So look, you've got direct and indirect.

06:40 Those are the main two columns.

06:42 Look at what is similar? Well, we talked about consolidation pattern in a chest x-ray.

06:48 We're talking about ground glass opacities.

06:51 That's the fancy name for what we're talking about the white out or the opacities you saw on the chest x-ray in the beginning of this.

06:58 They're the same for direct or indirect injury.

07:02 So I wanted you to have that concept in your mind.

07:05 But go to the first two levels.

07:07 Look at the difference between if a patient's initial insult or event was direct or indirect.

07:14 That's the key to understanding some of the differences you may see clinically.

07:19 See with direct injuries, they have greater alveolar collapse.

07:23 Oh, that is no good.

07:26 They've got thick discontinuous hyaline membranes.

07:30 Now that word is going to come up again.

07:33 So I want you to underline hyaline membranes.

07:37 This is a waxy membrane made up of all that trash that's happened due to the inflammation.

07:42 They line the alveoli and then you really have impaired gas exchange.

07:48 So with a direct injury, you've got a greater risk for collapse and you have these thick, thick hyaline membranes.

07:55 Now, both will have them but you'll see it more in a direct lung injury.

08:01 Now what's different about indirect lung injuries? Well, they have interstitial edema and vascular congestion, you're going to see more of that.

08:09 Can either of these appear in both? Absolutely! But I wanted to give you a clinical picture about the differences you may see depending on your patient's initial injury.

08:20 Okay, so now let's look at a healthy of aveolus first.

08:23 Let's bring this all back around and take a look at a healthy alveoli.