Glucose Lab Values

The normal value of glucose is 70 to 115 milligrams per deciliter. It may vary depend on the facility you’re at or if you're using some sort of bedside testing which we will get into later. But for the most part a patient blood glucose should be between 70 and 115. I'm sure that we’re all really familiar about the importance of glucose when we're managing our patients, but I think we should go back to why that is.

First off glucose comes from carbohydrates in our diet. We eat them and then they are broken down in our digestive system. The reason we need glucose is because when they are broken down through glycolysis, it's used for energy and it's the energy production unit for all of our cells. But here's where things get tricky.

We have this hormone insulin and it's produced in our pancreas. And the reason we need insulin is because it is essentially the key to getting glucose into all of our cells for cellular respiration or cellular energy use. Let's go through this process a little bit. So this is the phospholipid bilayer, so the outer cell wall of a cell. And this unit right here is the insulin receptor for a cell. There's an alpha subunit and a beta subunit. What happens is insulin is produced by the pancreas and comes down and fits into this receptor like a key. It then activates the beta subunit and a whole cascade of events happen. What happens are that these glucose transporters come and attach themselves to the cell wall and allow for the influx of glucose from the outside of the cell to the inside of the cell. Cool, right?

So what happens if there's a problem with insulin? Well we have a couple of different things that happen. You can either have a problem with the production of insulin, which is essentially diabetes. Diabetics have little or no insulin to come activate this influx of glucose into the cell. That's going to create higher levels of glucose in the blood where it shouldn't be, because it should be inside the cell. Sometimes there's a problem with this actual receptor, and this is where you get into issues of insulin resistance, we'll get into those a little bit later. Either way, the glucose is outside of the cell where it shouldn't be, and we need to get the glucose inside the cell. So for diabetics, this is where additional insulin comes into play. Because their problem is with the actual insulin production, by supplementing them with insulin, allows the insulin molecules to go to the cell, activate those glucose Transporters, and it moves the glucose into the cell.

So what are we need to be thinking about when we're looking at glucose labs in particular?

First off they’re going to be in most of your lab panels, so a lot of your liver labs and chemistry's and otherwise you're going to contain this as a default. The other thing is that you need to submit this to the lab in a green or gray tube. Most of the time it's going to be green, because it's going to get you a quicker result, and usually that's the standard.

The other time you're going to actually do glucose is when you have a bedside glucose testing, or capillary blood glucose or cbgs. This is when you're going to be responsible for checking the glucose at the bedside for your patients who need better glucose management. There's a lesson on glucose monitoring, as well as other endocrine disorders associated with glucose testing so I encourage you to check those out

So when are you going to see I'm normal glucose values? You are going to see elevated glucose levels in diabetic patients because they either lack insulin or don’t have enough and also with HHNS, or hyperglycemic hyperosmolar nonketotic syndrome. There are lessons on both of those, so go check them out. Another time you'll see it is with pancreatitis, because pancreatitis disrupts that process of insulin production. You also see it in cases like renal failure.

Steroids, either through medication or with the problems of certain cortisol stimulating diseases or illness like Cushing’s disease or stress can cause insulin resistance. The ways this happen are complicated, but the thing you need to remember is that if your patient is subject to stress or on steroids for some reason, know that it can keep the insulin from working and cause the glucose to jump up.

Now there are a couple of situations where you're going to see decreased glucose levels. If a patient has a tumor called an insulinoma, it will actually cause an overproduction of insulin there for driving blood glucose down. Also cases of hypothyroidism and hypopituitarism will cause it in addition to malnutrition, so they're essentially not getting enough food, and they lack energy. The other time you're going to see it is if you're patient actually receives an overdose of insulin, so now you've got too much insulin and its use up all the glucose and there's nothing reserve.

So far this lesson for nursing concepts we've really focused on lab values and glucose monitoring when we're watching the actual lab for glucose.
So let's recap.

Your normal value for your glucose is going to be 72 115 milligrams per deciliter.

Remember that insulin is the key that is required to get the glucose from the outside of the cell to the inside of the cell.

When you're taking care of your patient is going to be very common for you to do bedside testing, so make sure you check out the glucose monitoring lesson for tips and tricks. Also most of your labs are going to include glucose in there testing.

When you see an elevated glucose, think that there's too much glucose in the blood and we need to move it into the cell. So they either lack the ability to utilizar insulin, they don't have enough insulin, or that you have some sort of insulin resistance.

If you have decreased glucose, then think they either don't have enough sugar or they have an overproduction of insulin.

That's it for our lesson on glucose. Make sure you check out all the resources attached to this lesson. Now, go out and be your best selves today. And, as always, happy nursing!!