Nasogastric (NG) Tube Insertion

CHAPTER 1

Hi, everyone. My name is Deanna Rothman. I'm a general surgery resident at Massachusetts General Hospital, and welcome to our session on NG tubes. First, let's talk about what is an NG tube. An NG tube, or nasogastric tube, as its name implies, is a flexible tube that goes from a patient's nose into their stomach. There are multiple indications for why a patient may require an NG tube, so let's talk a little bit about what those indications are. The most common indication that you're likely to see on the surgery clerkship is GI decompression. In this case, an NG tube is used to decompress a GI system from above. For example, if a patient has a small bowel obstruction or an ileus after surgery, in both of those situations, the patient is not able to move their GI contents forward naturally through their intestines, and so we use an NG tube to decompress them from above. The next most common indication is for evaluation of a GI bleed. So if a patient presents with hematemesis, hematochezia or melena, usually we'll place an NG tube to exonerate the stomach as the source of the GI bleed. The next most common indication is postoperative care. If a patient had an esophageal, stomach, or a large GI surgery, sometimes we'll place an NG tube intraoperatively. because either we anticipate they have an ileus or it can be protective for the anastomoses that they now have. The last most common indication is feeding or medications. There are several reasons why patients may not be able to take in food orally. For example, if they're sedated or if they're unable to swallow on their own. If both of these situations, we'll keep an NG tube in to assist with their feeds and with getting their medications. Sometimes patients will need this NG tube and this medication and food support for a longer amount of time, so we may exchange a larger NG tube for a more flexible tube like a Dobhoff a little bit later. These are the most common indications for an NG tube, but let's talk about some of the contraindications to placing one. First is severe facial trauma. In cases of severe facial trauma or fractures, there's concern that if you place an NG tube, it won't go the correct way and may end up damaging other nearby structures. So in those situations, we avoid placing NG tubes. Another common contraindication for NG tube placement is recent GI surgery. I mentioned when talking about indications that one of the common reasons why we place NG tubes is postoperatively after a patient had either an esophageal, stomach, or large GI surgery. If this NG tube were to fall out, however, and this patient recently had esophageal or gastric surgery, we would not place another one just in case it would go through that now healing anastomosis, so that would be another contraindication to NG tube placement. Another contraindication to NG tube placement is esophageal varices. In patients that have esophageal varices, it's more challenging and more dangerous to place an NG tube. Potentially the NG tube could injure one of these varices and cause the patient to severely bleed. Therefore, in these situations, we do not place NG tubes. The last most common contraindication to NG tube placement is coagulopathy. Like patients with esophageal varices, patients with severe coagulopathies are at higher risk of severe bleeding after NG tube placement, so we usually hold off on placing NG tubes in these patients. Now, let's review all the materials you'll need for your NG tube placement.

CHAPTER 2

Let's go through all of the materials you'll need for your NG tube placement. First is a bucket. Oftentimes, these patients are already nauseous and placing the NG tube can make them even more nauseous, so it's good to have a bucket just in case. The bucket is also helpful to help carry everything to the room you're going to. Next is a chuck. Similarly, sometimes there can be spillage of GI contents, and so it's good to have a chuck to keep the patient and the bed clean. Next is our suction tubing. This is what we'll use to connect the NG tube to the suction canister in the hospital room. Next are gloves. Gloves are important for our own safety and protection to make sure that we keep ourselves clean. Next is our actual NG tube. There are different kinds of NG tubes, and they all come in different sizes. For this situation where we have a patient that has a small bowel obstruction, we'll be using the NG tube for GI decompression, and so I recommend using an NG tube with a large French. This one is an 18 French NG tube. Sometimes you'll see 12 or 14 Frenches available as well, but those smaller Frenches may end up getting actually clogged more easily since they have a smaller diameter of the tube. So an 18 French is a larger diameter, less likely to get clogged, better for GI decompression. Next is a cup of water with a straw. This is what we'll ask the patient to drink from while we're placing the NG tube. It's helpful to have a straw. It makes it a little bit easier for them to drink the water. Next is our lubricating jelly. This is what we'll be placing on the NG tube to help it go down the nares. Once the NG tube is placed, there are several ways that we can adhere the NG tube to the patient. First is with this specific bandage. This bandage goes over the nose and then adheres to the NG tube to prevent it from falling out. Then we also have tape and a safety pin, which we use to wrap around the NG tube and adhere the NG tube to the patient's johnny to also prevent it from coming out and also to make it a little bit more comfortable for the patient. Now that we have all of our materials, let's go see our patient.

CHAPTER 3

There are several steps to placing an NG tube besides the actual NG tube procedure. These steps are consenting and discussion with your patient, making sure you have all your materials at the ready, having the patient positioned appropriately, then placing the actual NG tube, and then post-procedure steps. Let's go through each of those steps together. First is having a discussion with your patient. In this case, this patient has a small bowel obstruction, and so we'll be placing an NG tube for GI decompression. At this point, I've already had a discussion with my patient and consented them for the procedure. They understand why we're doing the procedure and why we think it's most appropriate and are willing to proceed with the next steps. Next is to make sure you have all your materials at the ready. As you can see, I have a bucket, a chuck just in case. I have my NG tube, and you can see the NG tube is already lubricated. And I also have my suction canister ready to suction. Most hospital rooms have a suction canister similar to this one. It's important to make sure it's all ready to suction and that you have your suction tubing ready to go. I also like to make sure I have a cup of water with a straw for our patients to drink from. I'll usually have either the patient hold it, or I'll have a nurse or someone else assisting me able to hold the cup for us. Now that I have all my materials ready, I'll position the patient appropriately. So as you can see here, the patient is positioned upright and usually I will recommend that they tuck their head as well. That helps close the airway and open the esophagus to make sure the NG tube goes the right way. I sometimes will also have my hand behind the patient's head to encourage them to maintain that position. Once I have everything positioned and all my materials at the ready, you can place your NG tube. I usually do the the placement in two steps. First, I advance the NG tube up to the posterior nasopharynx. At that point, you'll feel a little bit of resistance. Once you pop through that resistance, that means you're in the right place, and that's usually around 12 centimeters of the NG tube. At that point, once I feel that release, I'll ask the patient to start drinking water. As they're drinking water, they help swallow the NG tube and go down into the esophagus. At that point, you keep pushing up until about 60 to 65 centimeters on the NG tube, and then you know you're probably in the right place. There are some common NG tube pitfalls you may encounter when placing your NG tube. So let's go through three common ones and how you can tackle them. So first is a deviated septum. Oftentimes, patients may have a deviated septum, which will make it more challenging to get through the nose. How oftentimes how this will present is that you'll be trying to get your NG tube to the posterior nasopharynx and encountering a lot of resistance. In that situation, it's worth trying the other nostril to see if you can get an easier passage. Usually there's one nostril that's a little bit easier than the other in most patients. Second is NG tube coiling. Sometimes you'll find that the NG tube gets coiled in the patient's mouth. In this situation, it's best to immediately pull back the NG tube, let the patient have a little bit of a breather, and then encourage them once again to maintain their head tucked. That tucked position will help the NG tube go into the esophagus instead of coiling in the mouth. A third common pitfall that can happen with placing an NG tube is that the NG tube goes down the airway instead of the esophagus. Some signs of this is that your patient may start coughing or you might have increased resistance around 20 centimeters of the NG tube. If this happens, it's important to draw back your NG tube pretty quickly. If you're not sure if you're in the airway or the esophagus, something you can ask your patient to do is to say something. If they're not able to verbalize, usually that's a sign that their vocal cords aren't able to oppose and you are in the airway. So it's important to pull your NG tube back pretty quickly, let your patient regain their breath and then try again. So now let's go through placing the NG tube together.

CHAPTER 4

So I start by introducing the NG tube to the nare, and what you'll see is that I'm actually pushing directly towards the back of the head rather than up the nose, which is a common mistake most people make. As I'm pushing to the back of the head, I'll reach some resistance right around 10 to 12 centimeters, and that's when I'm hitting the posterior nasal pharynx. I let the patient know this is probably gonna be a little bit uncomfortable. Once I pop through and I feel that release, that's when I'll start asking the patient to start drinking water. As they're drinking water, I'm gonna continue to advance the NG tube. I'll keep advancing up until I reach about 60 to 65 centimeters. It's also important to note, as I mentioned, if you get any resistance at any point during here, it's important to stop and pull back. Now that we're at 65 centimeters at the nare, I'm gonna hold onto my NG tube and try to adhere it to place to make sure it's not gonna go anywhere. What I'm gonna be using for that is this kind of bandage that's specifically designed for NG tubes. As you can see, it goes around the nose and wraps around the tube as well to prevent it from moving. Now that I know that my NG tube is not gonna go anywhere, I'm gonna put it to suction. At this point, I should be seeing gastric content coming out. If I don't or if I see anything else, I'll take it off of suction. Now that I'm seeing gastric content, I try to position the NG tube so that it's comfortable for the patient. To do that, I'll make a little loop with tape. And then adhere it with a safety pin to the patient's johnny. I usually like to loop it up like this just so it's not pulling down on their nose. And once the NG tube is positioned, you're all set. Last step will be to get a chest x-ray to make sure that your NG tube is in the correct position. So let's go look at a chest x-ray now together.

CHAPTER 5

So this is an example of a patient who had an NG tube placed and then got a chest x-ray afterwards to confirm its placement. First, let's review the chest x-ray. As you can see, we have both lung fields, the right lung here and the left lung. You can also see the trachea here in the midline leading to the right main stem bronchus and the left main stem bronchus. Here you also see the heart and the heart border, as well as both diaphragms. Here's the right diaphragm and the left diaphragm. The left diaphragm here looks a little bit translucent, and that's because of a large stomach bubble underneath, which is why we placed the NG tube. Now we can look at the NG tube, which as you can see through the radiopaque stripe is going down the esophagus here following through the GE junction, which we assume is right here where the diaphragms are, and then into the stomach. Here, we can't actually see the tip of the NG tube. It goes beyond the chest x-ray. But what we can see is a small gap in the radiopaque line. All NG tubes have that gap, and that's where the last port is. So you ideally wanna see that this gap is below the GE junction as well. So this is a well-placed NG tube. On the other hand, this is an NG tube that is not properly placed. Once again, we're following the NG tube's radiopaque stripe going down to the esophagus, but here we see that the radiopaque strip, the little gap that indicates the last port is actually above the GE junction, and we could see that because our diaphragms are right here, and so therefore we expect our GE junction to be right around here. So since that port is up here, that means that the tip of the NG to which you could see here is not advanced far enough into the stomach, and so it needs to be advanced more, probably a few centimeters. So this is an improperly placed NG tube. We'd go back and advance it farther in this patient, probably at least a couple centimeters. Then repeat a chest x-ray to confirm it's now in the correct position.