Galactosemia (Nursing)

00:01 We're going to talk about an inborn error of metabolism called Galactosemia.

00:05 So what exactly is galactosemia? It is an inefficient metabolism of the sugar galactose.

00:16 Now, where do we get galactose? So, cow's milk is a primary source of galactose.

00:20 Milk products, including cheese and yogurt.

00:24 And human milk will also contain galactose.

00:29 There are some secondary sources.

00:31 So you can find some galactose, in fruits and vegetables.

00:37 And we metabolize galactose so that our cells can use the glucose that we can get from this.

00:44 And our liver can store that as glycogen.

00:48 So how does that work exactly? Well, we're going to take in lactose, so cow's milk and cheese, and those kinds of things have lactose them.

00:58 So we're going to take in lactose, and then with the addition of water, and an enzyme called lactase, that gets broken down into galactose and glucose.

01:09 Now, our body can use the glucose but it can't quite use the galactose yet.

01:14 And this process can go back and forth.

01:18 So how do we use the galactose that is produced by this reaction? It turns out that we need additional enzymes to help break this galactose down and turn it into glucose that our body can use.

01:32 So, I'm not going to try to pronounce these enzymes, but you'll have GALT, GALK, and UDP.

01:39 Those are the enzymes that are going to help this process along.

01:43 So, once those enzymes act on the galactose, then the body can use the glucose that is produced as energy.

01:53 If you don't have those enzymes, that is galactosemia.

01:58 That means that that galactose cannot be broken down, and it's not available for our body to use.

02:04 So each of the three enzyme deficiencies causes a little bit of a different disease expression.

02:12 So what are some signs and symptoms of galactosemia? So infants usually present in the first few days after birth.

02:19 And this happens when they've been started on either breast milk or formula which makes sense because this is the source of galactose.

02:26 It often the results of a newborn screening where you can detect galactosemia aren't back yet when this happens.

02:35 So what is this going to look like? In the early stages infants present and they look pretty sick.

02:40 They can have increased intracranial pressure, swelling of the brain, they can have kidney issues, they can look septic and shocky.

02:50 They will be spitting up and not tolerating feeds.

02:54 They might also be jaundice, which means that they might have this yellowish tinge to their skins and in the whites of their eyes.

03:01 And this indicates that they are already going into liver failure.

03:06 Late signs of galactosemia also include neurodevelopmental impairment, cataracts.

03:13 For females, they may have premature ovarian failure.

03:16 So they're going to become infertile.

03:19 And they experience growth delay.

03:21 So there's some pretty serious effects.

03:24 Additionally, when infants come in and they're sick, we might notice some laboratory findings that might point us in the direction of an inborn error of metabolism, and particularly galactosemia.

03:37 So I'm not going to go through all of these labs, but just know that all of these systems are affected.

03:44 So, there's going to be labs that show that we are not really using carbohydrates, there's going to be signs of liver dysfunction.

03:51 As we talked about in a previous slide.

03:53 There's going to be signs that the kidneys are not happy.

03:57 And you might even see Hemolytic Anemia on your labs.

04:01 So how do we diagnose this? Classic galactosemia should be considered in any newborn who presents with findings that are shocky or findings that may say that they're having neurological changes like seizures.

04:17 And we don't have a great underlying cause.

04:19 We don't have another condition to blame this on, and we can't find an infection.

04:24 In those cases, you're going to suspect an inborn error of metabolism like galactosemia.

04:30 Even if we don't have the newborn screening back yet, we want to test for this because it may take a couple of days for the newborn screening to come in.

04:40 So how do we test for this? We can specifically look for that enzyme activity.

04:45 So you can look for the GALT activity, GALK, and GALE deficiency.

04:53 So any abnormalities there is going to really point you toward galactosemia.

04:59 This test notably can be affected if the infant or child had to have a red blood cell transfusion.

05:07 So and this can be affected for up to three months.

05:10 So if your patient has had to have a transfusion, then we probably need to do DNA testing instead, if we suspect this inborn error.

05:20 Now, what do we do if our patient does have galactosemia? So as with a lot of inborn errors of metabolism, there are going to be a lot of dietary restrictions.

05:31 So we want to make sure that they're not taking in a lot of this lactose and galactose in their diet.

05:37 We also need to give them calcium supplements, because for most of us, we get a lot of our calcium from those milk products.

05:45 And if we're avoiding those in these children, then we need to make sure that they're getting the appropriate amount of calcium.

05:51 We want to involve a metabolic dietician because these diets can be a little bit tricky, and they can be hard to adhere to.

05:58 So the help of a metabolic dietitian can be really, really important.

06:03 It's going to take a multidisciplinary team to manage these patients.

06:08 And there's really going to be ongoing monitoring of many parameters.

06:12 And this is going to include the child's neurodevelopment their speech, making sure their eyesight is okay, and watching their pupil role development.

06:22 So let's use the clinical judgment model to think through galactosemia.

06:28 One of the first steps that we do is that we recognize the cues in our patients that make us think of an inborn error.

06:34 And in these cases, you might have poor feeding, you might have that yellowish tint to the skin, you might have a patient that is looking really ill almost like they have septic shock.

06:48 Occasionally, you're going to have patients that would present a little bit later.

06:52 So if you have a child that has cataracts, which is pretty unusual, or you have a child that has growth delay, it would be pretty hard to detect premature ovarian failure at this point.

07:04 But any of those things would point you in the direction of the hypothesis should be an inborn error and likely galactosemia.

07:13 So once we've recognized some of those cues.

07:16 To analyze them, we can send off the blood tests.

07:19 We can see if that enzyme activity really is impaired.

07:24 Once we've determined that, then we're going to take those actions.

07:28 Let's get that diet under control and make sure we're not taking in a lot of lactose and galactose.

07:34 Remember, lactose will turn into galactose.

07:37 And we want to make sure that our patients are getting those calcium supplements, and that they're involved with a metabolic dietitian.

07:46 So when you're using the clinical judgment model, just remember that there are several steps that we go through.

07:50 And we've just highlighted a few for you to make it a little bit easier.