Med-Surg - Gastrointestinal System, part 3: Diagnostic Tests

Updated:

The following diagnostic tests: esophagogastroduodenoscopy (EGD), sigmoidoscopy, colonoscopy, and GI series. Lab values associated with the gastrointestinal system, including: AST, ALT, amylase, lipase, bilirubin, ammonia, albumin, prealbumin, and total protein. What can cause elevated or decreased levels of these lab values.

Full Transcript: Med-Surg - Gastrointestinal System, part 3: Diagnostic Tests

Hi. I'm Cathy with Level Up RN. In this video, I am going to talk about diagnostic testing related to the gastrointestinal system. At the end of the video, I'm going to give you guys a little quiz to test your knowledge of some of the key points I'll be covering in this video, so definitely stay tuned for that. And if you have our Level Up RN medical-surgical nursing flashcards, definitely pull those out so you can follow along with me.

The first test I'm going to talk about is an EGD, which is an esophagogastroduodenoscopy.

This is a procedure that is done under moderate sedation, where a scope is inserted down the throat, and the esophagus, stomach, and the duodenum are visualized with that camera. And the patient needs to be NPO for about six to eight hours before the procedure, or per facility policy. No kind of bowel prep is needed for this procedure because we're going in this way.

However, with a sigmoidoscopy, which goes up this way - this procedure visualizes the anus, rectum, and sigmoid colon - anesthesia is not required, but you do have to have the patient be NPO after midnight before the procedure, and they will need to drink polyethylene glycol, some kind of drink such as GoLytely, to clean out those bowels.

Then we have a colonoscopy, which is done under moderate sedation, like the EGD.

With a colonoscopy, we scope much further in so we can visualize the anus, rectum, sigmoid colon, descending colon, transverse colon, and the ascending colon. So just like with the sigmoidoscopy, the patient will need to be NPO after midnight, and they will need to consume some of that polyethylene glycol in order to clean out the bowels. So any time I talk about a colonoscopy, I remember one night as a new grad on night shift, where I had to give, literally, like four gallons of GoLytely, which is polyethylene glycol, to a bed-bound patient. And let me just say I will never forget that evening, and thank goodness for my amazing CNAs who were there by my side, helping with that situation.

Next, we have a gastrointestinal series, or GI series, which is a procedure that is used to identify GI abnormalities such as an ulcer, tumor, or obstruction.

So with this procedure, the patient will drink some barium and x-rays are taken as the barium moves through the patient's GI tract. So the patient will need to be NPO for eight hours prior to the procedure. In addition, they should not smoke or chew gum for eight hours prior to the procedure and then after the procedure. You want to encourage a patient to increase their fluid intake in order to flush out that barium. In addition, you should warn them that their stools will be whitish in color for several days until that barium is cleared out.

Lab values associated with the gastrointestinal system as well as the expected range for each of those lab values can be found in our medical-surgical nursing flashcard deck. You can also find those lab values and ranges in our lab values flashcard deck, which also contains my silly ways and mnemonics for remembering those ranges. So if you struggle with lab values, you may want to check that deck out.

All right. AST and ALT, if those levels are elevated, that is strongly indicative of liver dysfunction, such as cirrhosis or hepatitis.

Amylase and lipase are pancreatic enzymes. So if we have an increase in either of those enzymes, then that is indicative of pancreatic dysfunction, such as pancreatitis.

Bilirubin will be elevated in the presence of liver dysfunction. Other causes of elevated bilirubin include hemolytic anemia, as well as a blood transfusion reaction.

Ammonia will be elevated in the presence of liver disease. So a patient with advanced cirrhosis will often have elevated ammonia levels, and that can cause encephalopathy. So ammonia will build up in the brain and cause confusion in that patient.

Albumin, prealbumin, and total protein may be decreased in the presence of liver dysfunction, but these values will also be decreased if the patient has malnutrition.

All right. It's time for a quiz. I have. Three questions for you. First question, what test visualizes the esophagus, stomach, and duodenum under moderate sedation? The answer is an EGD, or esophagogastroduodenoscopy. Question number two, what patient teaching should you provide a patient after a GI series? The answer is you should teach them to increase their fluid intake to help flush out that barium. And you should also teach them that their stool will be white for several days until that barium is cleared out. Question number three, what two labs may be elevated in the presence of pancreatitis? The answer is amylase and lipase. Remember, those are the two pancreatic enzymes that will be elevated when we have pancreatic dysfunction.

Okay. That's it for this video. In my next video, we will get into disorders of the GI system, so definitely stay tuned for that.

Back to blog

Leave a comment

Please note, comments need to be approved before they are published.