Lab Values, part 22: Amylase & Lipase

Hi, I'm Meris, and in this video, I'm going to be talking to you about two lab values, amylase and lipase. Let's go ahead and get started. All right, so first up, we're going to talk about the lab value amylase. Now, amylase, this is a digestive enzyme that's used to break down carbohydrates. It is produced both in the saliva, but also in the pancreas. It's a pancreatic enzyme. And the expected range here is going to be 30 to 220 units/L. So again, we are expecting that there's going to be a good amount of this. It is a normal thing to have in my body. I should be making it. I should be using it to break down carbohydrates. So we don't want this one to be super close to zero. This one can go all the way up to 220. Now, what if I have elevated amylase levels? Well, a couple of things could be going on. The thing that we see a lot is going to be acute pancreatitis. Pancreatitis is one of these conditions where you will see marked increases in these labs. So this is a very, very likely thing that they're dealing with if they have an elevated amylase level. But there's other things that could be going on, pancreatic cancer. Again, pancreatic dysfunction. Cholecystitis, this one, I have a gallstone or gall inflammation, gallbladder inflammation, or infection or something is going on. And this is going to cause me to actually have some pancreatic involvement because of how these two things are connected through the bile ducts, okay? So that's where we can see cholecystitis causing this elevation in amylase as well. And then, of course, a salivary gland infection. If I have an infection of my salivary glands where amylase is also produced, then it's going to build up. It's not going to be able to get out. And we're going to have that really intense rise in our amylase levels.

Now, let's switch gears and talk about lipase. Now, lipase is very, very similar. This is a protein that's released by the pancreas into the small intestine. And this is used to help break down fat. So lipo, right, meaning fat, and a ase is an enzyme. So this is the fat enzyme, the enzyme that breaks down fat. Super duper important, right? I need this enzyme so that when that food gets moved from my stomach down into my small intestine, that there is an enzyme there to break down fatty foods, lipase. Well, what if this level is elevated? Because again, here we have an expected range of 0 to 160 units. We are anticipating that we're going to have some lipase and it's going to be in there in that range. But what if it's elevated? What if I'm looking at this patient and their lipase is elevated? Well, this, again, is very suggestive of pancreatitis. An elevated lipase level in particular is very suggestive of pancreatitis. But again, pancreatic cancer, any sort of pancreatic dysfunction goes hand in hand with lipase. The thing that I want to call your attention to, though, is the whole point here is, yes, you will see amylase and lipase being run together, but lipase is much more specific for pancreatic issues. So it is going to be a much more specific lab for diagnosing acute pancreatitis. So if my patient comes in and they have an amylated - sorry - an elevatedamylase level, but not an elevated lipase level, that tells me with pretty good certainty. This isn't a pancreatic issue. Maybe something else is going on. Maybe I need to look at salivary glands. Maybe we need to look and see is there cholecystitis. But that is why it is so helpful to have that lipase value.

Now, this is just a little pearl for you from my own lived experience. I am a person who suffers from acute pancreatitis. I have been having acute pancreatitis off and on for about the last 12 years, and we have no idea why. About 30% of people who experience it will never know why they call mine recurrent acute idiopathic pancreatitis. I don't have chronic pancreatitis. I have recurrent acute pancreatitis. I'm not a drinker. I don't use IV drugs. There's nothing like that going on, and they can't figure out why. But the first time that I went, I described it as chest pain. It felt like chest pain to me because it's actually up here under my rib cage is where it hurts me. They did not draw an amylase or a lipase. They did a cardiac workup and they cleared me and they sent me home and said, "Huh, who knows?" But eventually, when I went back again having that same pain, one of the providers said, "I'm going to draw a lipase level just to be on the safe side." And when she did, it came back at over 1,000. And when I followed up with my GI doctor - this is the thing that I want you to know - I told him I was diagnosed with acute pancreatitis, and he kind of rolled his eyes and said, "Oh my gosh, the emergency room is so quick to diagnose people with pancreatitis because their lipase was elevated." He was like, "What was your lipase? Like 300?" And I said, "No, it was over 1,000." He said, "Oh, well that is acute pancreatitis." He went on to tell me that by their standards in the GI world, they don't consider it acute pancreatitis unless it is three times higher than the top normal number. So again, for the lipase, we're talking about 160. So it needs to be three times higher than that for him to have considered that related to acute pancreatitis. So not that this matters for you to keep in your memory, but it's just one of those things I like to pass on because now when I'm caring for a patient and I think, "Could this be pancreatitis?" And I look at that lipase, I'm looking to see like, is it really elevated? How high is it elevated?

All right, I'm so glad you stayed until the end because I'm going to test your knowledge of some key facts provided in this video with some quiz questions.

Elevated levels of amylase and lipase are most indicative of which condition?

Acute pancreatitis.

How do lipase levels compare to amylase levels in diagnosing pancreatic inflammation?

Lipase is more specific than amylase in diagnosing pancreatic inflammation.

All right, that is it for this video. I do hope you learned something. I'll see you in the next one. Thanks so much and happy studying.