Urine Casts: Types (Nursing)

00:00 I've organized information about casts.

00:03 Now that you know what they are. I've organized it in a chart.

00:06 Because I think this is the simplest way for you to take this information, and make it your own.

00:11 So the first column is the type of cast.

00:13 The second one is what it's made of? That means the predominant cellular elements.

00:18 And the third one is possible causes.

00:20 So when you look at results of casts, and you see the type, this is a great chart for you to refer to, to understand what that means to your patient.

00:29 So let's start with the Hyaline cast.

00:32 It's the most common type of cast it's made of a solidified mucoprotein remember that Tamm-Horsfall protein.

00:37 Normally, in someone's urine you might see between zero to five of these on a low power field.

00:45 So it's predominantly made of mucoproteins.

00:48 And it could be a sign of pyelonephritis, chronic renal disease, dehydration, or vigorous exercise.

00:56 Okay, blah, blah, blah.

00:58 I know I've put a list out there for you.

01:00 And sometimes that's hard to remember.

01:02 But keep in mind casts are formed when your inflow is low.

01:06 When that urine is going to be extra concentrated, or in an acidic environment.

01:11 So we're talking about Hyaline cast.

01:13 Why does it make sense that you'll see it in pyelonephritis, or renal disease? Well, those classically have low renal flow.

01:21 But what about dehydration and vigorous exercise? Well, those are acute things. Those come on in an instant.

01:28 So dehydration is less intravascular volume, less stuff flowing through my kidneys.

01:36 And that's why you're more likely to develop these casts.

01:39 Vigorous exercise? Oh, yeah, that's not a stretch.

01:42 Vigorous exercise could cause the dehydration.

01:46 So that makes sense.

01:49 Anytime you see a list like this, don't just let it roll by you.

01:52 Stop. Pause.

01:54 Look for ways that you can chunk information to make it make sense.

01:58 So we know this is a pretty common type of cast made of mucoproteins.

02:02 And we're going to see it most likely with low urine flow, concentrated urine or in acidic environment.

02:10 Next up, let's look at Erythocyte.

02:12 So these types of casts are made up of red blood cells.

02:17 Now, you'll see this in glomerulonephritis.

02:20 But it might be normal if the patient plays contact sports.

02:23 Because they can take some pretty big hits in the contact sports.

02:27 So if intact erythrocytes are visualized on a microscopic exam of their urinary sediment, this can help us distinguish between hematuria and other conditions.

02:39 So microscopic examination can detect red blood cell cast, or dysmorphic, right? Difficultly shaped, oddly shaped, abnormally shaped red blood cells.

02:52 Because we divide hematuria into glomerular, renal, and neurological ideologies.

02:59 Okay, that's a lot of vague words.

03:01 So let's go back and break that own.

03:03 So you get it all in your notes.

03:05 If I see erythrocytes cast that we would classify as erythrocytes we know they're made up of red blood cells.

03:13 Now, this could be a renal problem or a non-renal problem, right? So we divided into glomerular, renal, and urologic ideologies.

03:24 So, if I see red blood cells, this is going to require further follow up on my part.

03:31 Next, leukocytes. Those are white blood cells.

03:34 You're gonna start to see a common theme here, right? Pyelonephritis, glomerulonephritis, interstitial nephritis, renal inflammatory processes.

03:44 White blood cells are part of the inflammatory process.

03:48 Look at every word in that possible causes.

03:51 itis, itis, itis...

03:54 Cool.

03:55 Inflammatory process is what itis means because itis means inflammation of whatever is before that.

04:03 So it would make sense that leukocyte, or white blood cell casts are the result of inflammation.

04:11 Now, so get epithelial.

04:13 We're talking about renal tubule cells.

04:15 So a cast that's an epithelial cast is made up of renal tubule cells.

04:21 Now this can be the result of acute remember that's something that's happening right now.

04:25 Acute tubular necrosis.

04:29 That's no bueno.

04:31 That's not a good thing.

04:32 So the reason I'm going to see casts, they're made up of renal tubule cells They're going to be called epithelial but that could be acute tubular necrosis.

04:42 It might also be interstitial nephritis, eclampsia from seizures, nephritic syndrome, and allograft rejection, heavy metal ingestion or renal disease.

04:55 Okay, awesome.

04:56 How do we chunk that together? Well, I want you to first file away, if you see epithelial cast on a microscopic report, we've got a big problem.

05:06 We have to figure out if it's something because of an event that has happened, and you have that acute tubular necrosis, or we've got some other more complex things going on.

05:16 Honestly, I don't recommend that you memorize this list.

05:19 I just don't.

05:20 Its too many things.

05:22 This real estate up here is precious.

05:24 What I want you to know is if you see a renal tubules cells, right? if we see an epithelium cast, it's a big deal.

05:32 I would remember acute tubular necrosis, and a lot of other serious things.

05:38 That's what I would do.

05:40 So I'm gonna ask you, just write that write in your note.

05:42 Acute tubular necrosis and a lot of other serious things.

05:46 Call that good.

05:47 There's only so much information your brain can memorize.

05:50 And I want you to keep the most important things right at the top.

05:54 Okay, let's look at a granular cast.

05:57 Now, it's made up of various cell types.

05:59 And this means, I'm sad to say advanced renal disease.

06:04 It breaks down the cellular cast and adds plasma proteins like albumin or immunoglobulin.

06:09 This is a problem.

06:11 So if you have granular casts made up of various different cells, hey, that's a difference.

06:17 That's one way you can help your brain chunk information.

06:20 It is various cell types, right? It can be kind of all over the map.

06:24 So what could cause this? Chronic renal disease.

06:28 This is a sign that this has been going on for a long time.

06:32 It's not an acute problem. it's a chronic problem.

06:35 And you have the stasis or slow down, or stopping in the nephron.

06:39 You might see it in shorter term if they have dehydration or super vigorous exercise.

06:45 But usually, this is a sign of chronic disease.

06:49 Now, waxy cast. Just sounds weird to me.

06:53 But again, this is because of renal stasis or nephron obstruction.

06:58 Okay, this is a serious problem.

07:00 So it's made up also of various different cells.

07:03 This tells me there is very low flow urine associated with this, right? So severe and long term kidney disease and chronic renal failure.

07:13 You're going to see waxy cast.

07:15 So when cellular cast remain in the nephron for a long time, because the flow is so low, before they're actually flushed into the bladder, the urine that's in the bladder.

07:26 The cells may degenerate.

07:28 They become kind of coarsely granular cast.

07:31 Later, finely granular class and ultimately a waxy cast.

07:37 So this is really not a good sign.

07:39 Granular and waxy casts are believed to come from the renal tubule.

07:45 But either way, we've got a bigger problem going on.

07:49 Now let's talk about fatty casts.

07:51 Nobody even likes the nam of that one either.

07:54 But these are hyaline cast plus fat globules.

07:58 There's no nice way to say that.

08:00 Hyaline cast and fat globules.

08:03 Now these are formed when lipid rich epithelial cells are broken down.

08:08 So that's where the fat globules come.

08:11 They come from epithelial cells that are lipid rich.

08:14 Now, this tells me we got a really high urinary protein nephrotic syndrome.

08:21 Again, none of these guys in this part of the chart are good news for your kidneys.

08:27 Now, these are called broad because they are larger than other cast.

08:31 So kinda personal. It's like the plus size cast, right? It's a broad because it is larger than the other cast.

08:39 They're a sign of end-stage chronic renal disease and are thought to be formed in the damaged and dilated tubules.

08:46 That's why they're so much bigger.

08:48 They're called broad, because that's an indication that this cast this mold of the tubules is showing you these tubules are so damaged.

08:57 That's why they are dilated and enlarged.

09:02 Now with crystal casts, these are present with urinary solutes, such as oxalates, urates, or sulfonamides.

09:10 The word I use there was urinary solutes, that means something that's dissolved in the urine.

09:17 Now oxalates.

09:18 We refer to before in this video series, that's oftentimes something when enough of that gets together, you can end up with an excruciating kidney stone.

09:27 So a little bit of crystals, not that big a deal, but you are more likely to be having problems later on.

09:35 So common crystal seen and even healthy patients include calcium oxalate, triple phosphate crystal and amorphous phosphates.

09:43 So it's not that big a deal unless they're getting more and more in number and they're clumping together.

09:50 Then you're really gonna care about but usually crystal casts are not that big a deal.