Fundamentals - Practice & Skills, part 20: Nasogastric Tubes
This article covers nasogastric or NG tubes — the different types, their indications, insertion, confirming placement, and removal. You can follow along with our Fundamentals of Nursing flashcards, which are intended to help RN and PN nursing students study for nursing school exams, including the ATI, HESI, and NCLEX.
What is a nasogastric tube?
A nasogastric tube is a tube inserted through the nare (nostril) to access (all the way down and into) the stomach. “Naso-” means “nose” and “gastric” means “stomach.”
One of the most common indications for using an NG tube is decompression for a bowel obstruction.
If fluid or gas has to be removed from the stomach, this can be done with an NG tube.
And an NG tube may be used to administer medications (similar to administration through an IV) or enteral feeding, that is, giving food through an NG tube, which is indicated for patients who are unable to tolerate oral intake.
There are two types of nasogastric tube, the double-lumen tube and the small-bore single lumen tube.
Double-lumen NG tube
A double-lumen tube, for example, the Salem Sump is, as its name suggests, a tube with a double pathway. (You can remember the Salem Sump is a double because it has two “S”s).
The double-lumen tube is a large-bore tube, and, because it is a bigger tube, it’s going to be more irritating in the patient’s nose. The good news is these larger tubes are used for shorter durations than a small-bore single-lumen tube.
In a double-lumen NG tube, one lumen is for suction, and the other lumen acts as a sump (i.e., it allows air to enter the body cavity in order to prevent the suction lumen from adhering to the gastric wall).
A double-lumen is best for decompression, though they are also used to administer feeds and medications.
Small-bore, single-lumen tube
A small-bore single lumen tube, like the Dobhoff or Levin, is the one that people are more familiar with. It is a skinnier tube, that is, its diameter is smaller.
Small-bore single-lumen tubes are best for medication administration and administering feeds.
NG tube insertion
The following are best practices, not hard and fast rules. Facility policies may differ, and individual schools may require extra steps.
When inserting a nasogastric tube:
- Elevate the head of the bed and cover the patient’s chest with a towel. Also provide a basin in the event of emesis (vomiting).
- Estimate the length of tube needed using the NEX method — nose, earlobe, xiphoid process. Measure from the tip of the patient’s nose, to their earlobe, and then to the xiphoid process, which is located at the bottom of the sternum. (The xiphoid process is the most distal edge of the sternum, or breastbone). This gives a measurement of just how much of the tube needs to be put into the patient. It is important to mark the measured length with either tape or an indelible marker — something permanent that is not going to wash off.
- Lubricate the tip of the tube. Having an NG tube inserted is a painful process. Lubricating the tube before insertion will help prevent damage to the patient’s nares (nostrils) as it is being inserted.
- Gently insert the tubing into the nostril toward the back of the patient’s throat.
- Encourage the patient to sip water through a straw or swallow as the NG tube is advanced. The act of swallowing helps to advance the tube into the esophagus and makes it a little more comfortable for the patient.
- Advance the tube firmly, but never push past resistance. If resistance is felt, stop advancing the tube.
- Once the tube is inserted to the predetermined (marked) length, secure it to the nose with tape.
Confirmation of placement
The only way to confirm that a nasogastric tube is in the correct place is with an abdominal X-ray.
Note that in order to avoid exposing the patient to unnecessary X-rays, only do this after placing the NG tube.
It is critically important to know that the tube has been correctly placed before using it (for example, it may have been fed into the lungs and not the stomach). Do not begin feeds or connect to suction until placement is confirmed by X-ray.
Confirming correct NG tube placement at the bedside
Sometimes, the location of the NG tube must be assessed at the bedside. In this case, before using the NG tube, its placement may be confirmed by aspirating (i.e., withdrawing) fluid and testing the fluid’s pH. The gastric environment is highly acidic, so if the tube is correctly inserted in the stomach, a pH test on the aspirated fluid will be less than 5.5 (indicating an acidic environment).
NG tube removal
Removing a nasogastric tube is much easier than inserting one.
First, cover the patient’s chest with a towel, as was done when inserting the tube.
Flush the NG tube with water or air. This is an optional step that clears the tubing.
Instruct the patient to take a deep breath and hold it. Then, remove the tubing quickly and smoothly, ideally in one fluid motion. This way the patient is not subjected to a long, drawn-out removal.
After, offer the patient oral care and a tissue to blow their nose.
Patient resistance to having an NG tube inserted
Remember, having had an NG tube inserted is not fun. Some patients may even try to impede the insertion process, for example closing off their throat area by putting their tongue back, so the NG tube cannot advance. In this instance, the tubing will just curl in the patient’s mouth.
Meris’ first NG tube insertion was with a reticent patient who did this — they put their tongue back so the NG tube coiled up in their mouth. When the patient opened their mouth to speak, the tubing spilled out!
What is important to know, besides always assessing to make sure that the NG tube is not curling in the mouth, is to confirm that the tube is threaded into the stomach.
Hi. I'm Meris. And in this video, I'm going to be covering Nasogastric or NG tubes. I'm going to be talking about the different types, their indications, insertion, confirming placement, and removal. So lots of really great content. I'm going to be following along using our fundamentals of nursing flashcards. These are available on our website, leveluprn.com. And if you already have a set of your own, I would invite you to follow along with me. I'm starting on card number 108. Let's get started. So, first of all, what is an NG tube? Well, Naso means nose, and gastric means stomach. So an NG tube goes to the stomach through the nose by way of the nose. Why do we use them? There's a bunch of different reasons. One of the big ones is going to be decompression. So if we have something going on where we need to remove fluid or gas from the stomach, we can do so with an NG tube. And then we can also use this for administering things like medications or even enteral feeding, so giving food through an NG tube. Now there's two different types that you need to be familiar with. The first is double lumen and the second is small-bore single lumen. So double lumen the example we give here is Salem Sump. You can remember that it's a double because it has two S's, Salem Sump. And the biggest use for this one is going to be decompression. So double lumen decompression. Okay. So this is a large-bore tube. So that means it's going to be more irritating to your patient's nose, but it works as a sump, meaning that it actually filters air through as well so that the tube does not stick to the stomach while it is set to suction. So this is ideal for suction, and you can administer feeds and medications through it. But it's going to be for a much shorter time than our small-bore single lumen tubes. We have a couple of examples here. Dobhoff is the one that you're probably familiar with. But small bore, meaning it's skinnier, the diameter is smaller. So this is going to be best for medication administration and administering feeds.
Moving on, we're going to talk about inserting an NG tube. So as you can see on this card, we actually have step by step in order how to insert an NG tube. Remember, this is just based on kind of best practices. Your school may have you do some extra steps. Your facility policies may be different. So this is just a guideline, not a hard and fast rule. I'm not going to go through line by line with you, but I want to point out some of the important things here. The first is how do we measure an NG tube? How do we know how much of this tube to put down into the patient? So we're going to use the NEX method, so NEX. So that's going to be measuring from the nose to the ear lobe and from the ear lobe to the xiphoid process at the bottom of the sternum. That's going to help us to estimate the length needed. And we're going to want to mark that length with either tape or an indelible marker, meaning something permanent. It's not going to wash off. The other thing is we have to lubricate the tip of the tube. This is very painful in general to have a tube put down. I've had an NG tube. It is not a fun experience. But if you don't lubricate it, you could cause real damage to your patients' [narrows?]. The other thing is that we are going to encourage our patients to either swallow or sip water and swallow as we advance the NG tube. The act of swallowing will help us to advance that tube and make it a little bit more comfortable for our patient. And then don't ever push past resistance. If you feel resistance, you need to stop.
Okay. Now let's talk about how do we confirm placement of an NG tube? The only way that we can 100% without a shadow of a doubt confirm that the NG tube is in the correct place is with an x ray. The radiologist will read the x ray and say, yes, it is in the stomach or, no, it's somewhere else. Right. And that's the only way that we can say for sure. But we also don't want to expose our patients to unnecessary x rays. So we are only going to do this after placing the NG tube. So when we place the tube, we're not going to use it. We're not going to put anything down it or set up suction until we know 100% sure it's in the right place. So that's very important because you don't want to accidentally feed the lungs, right? That could be disastrous. At the bedside, though, before you use the NG tube in the future, you want to assess placement by using one of multiple methods. The big one is going to be checking the gastric residual-- well, the gastric PH, I should say. When you pull back on the NG tube with a syringe, you want to test the PH of that fluid. Remember, we have a highly acidic gastric environment. So I am expecting that if I'm in the stomach, anything that I aspirate from there that's gastric fluid is going to have a PH less than 5.5.
All right. Let's talk about removing an NG tube. Removal is much easier than insertion. Big thing is that I want to say you should flush that tube beforehand. It's optional. You don't have to, but it clears that tubing. So use water or air to flush it, and then tell your patient to take a deep breath and hold it and remove that tube swiftly and quickly, kind of in one fluid motion so that you're not subjecting them to this long, drawn out removal. And then afterwards, your patient's probably going to want to blow their nose, and they may even want oral care as well. So be sure to offer that to them so that they can be as comfortable as possible. All right. I hope that review of NG tubes was helpful. If it was, please like this video. If you have a great way to remember something or if you have something to share with us, please do so in the comments. I would love to hear it, and I know everybody else watching would as well. Be sure to subscribe to the channel as well, because we have some pretty great stuff coming out and you want to be the first to know. So the next video in this series is going to cover parenteral and enteral nutrition. I hope to see you there. Thanks so much and happy studying.
Oh, my gosh. I totally forgot about my first experience putting an NG tube down when I was in nursing school. I had a patient who was confused, and he kept pulling his NG tube out. So we kept having to put the NG tube in. And so they offered me the chance to do it. And, first of all, I was just shaking, like absolutely shaking. But the patient kept kind of closing off his throat area. He was putting his tongue back, so we couldn't advance it. And it kept curling in his mouth. But he didn't want to say anything because he hated it. So it was just curling in his mouth. And then he would open his mouth to speak, and it would spill out. So be sure to assess to make sure that it's not curling in the mouth. But I really felt for him because having had an NG tube, I can tell you, they are not fun. You don't want one. So I totally get it. I felt really bad for him. But point being, make sure that you're going in the stomach because that was not in the stomach.
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