NG Tube/Corpak Residuals

[Steveo123]

As a nursing student, I have always been taught that before you place anything down an NG tube or Corpak that you should always verify the residual volume of stomach contents. During my clinical experiences and my work on a gastroenterology floor as a nursing assistant, I have never once seen a nurse check a patient's residual volume. Again, I was taught that before administering medication, increasing a tube feed, and even on a regular basis the residual volume should be measured to ensure that gastric emptying is occurring. Being on a floor where gastroparesis is common, I thought that it would happen for sure but it never does. Is this uncommon for me to see or in reality are residual volumes not usually measured unless specifically requested by the physician?

[Double-Helix, BSN, RN]

It depends on the policy on the floor/facility. Is there a policy and procedure manual that you can look at and see what the unit's specific policy is?

In my PICU, for example, NGT placement is verified each shift and PRN before using the tube. We verify placement by injecting air and listening for entry into the stomach.

We check residuals only when the patient is receiving feeding through the tube. If there is nothing going into the tube (one used only for intermittent medications, for example) then there is no need to check residual volume. Is it possible that you are confusing the need to confirm placement with the need for checking residuals?

If the patient is getting bolus feeds than we check residuals one hour post feed when we adjust the rate/volume of the feed. If the first residual is okay, we only check once per shift and PRN. If the patient is on continuous feeds, we check residuals once per shift and if we increase the rate of the feeding.

[Steveo123]

Is it possible that you are confusing the need to confirm placement with the need for checking residuals?

If the patient is getting bolus feeds than we check residuals one hour post feed when we adjust the rate/volume of the feed. If the first residual is okay, we only check once per shift and PRN. If the patient is on continuous feeds, we check residuals once per shift and if we increase the rate of the feeding.

I did mean the need for checking residuals. As far as placement, I was always taught that placement needed to first be verified by an xray (KUB) before the tube can be used. After being verified by xray, subsequent checks would be performed at bedside by checking the external length of the tube, the aspiration of stomach contents, and by checking the pH of the aspirated fluids. I was told that the "whoosh" method (listening for placement) is never an acceptable measure to determine location (but that it is still the most common technique).

But I've never seen a nurse do anything that you described that you do. It just baffles me that I have never seen it done, but now I at least know that it happens on your unit.

[Sun0408, ASN, RN]

If someone is on continuous tube feeds we check residual q4hrs adult ICU. If they are on bolus feeds we check just before administering. For meds, we do not check residual. It takes only a few seconds to check residual if the pt is tolerating TF's. Are you sure they are not doing it?

[Steveo123]

If someone is on continuous tube feeds we check residual q4hrs adult ICU. If they are on bolus feeds we check just before administering. For meds, we do not check residual. It takes only a few seconds to check residual if the pt is tolerating TF's. Are you sure they are not doing it?

I know it only takes a few seconds. I've done it dozens of times myself. But on the floor I work on I work directly with one nurse all day, assisting in everything that I do so I know for sure that they don't do it.

[Double-Helix, BSN, RN]

Yes, an x-ray should be obtained before using the tube. And yes, you're taught in school to aspirated contents and check pH, but that doesn't really happen in the real world. First of all, if the stomach is empty, you won't always get aspirate. Second, there's such a small difference in the pH of gastric vs respiratory secretions (gastric is approx 4 and respiratory approx 5.5) that the results may be confused. Plus, if your patient is on a stomach acid blocker or certain other meds, it will interfere with your pH. Third, try getting a hospital to actually buy pH test strips for gastric contents. If you inject air into the tube and listen in the stomach, you're going to hear it. It could still mean the tube is in the esophagus, but that's where tube length comes into play. And really, of the patient is at all alert and has a tube in their lungs- you're going to know it.

[Steveo123]

Yes, an x-ray should be obtained before using the tube. And yes, you're taught in school to aspirated contents and check pH, but that doesn't really happen in the real world. First of all, if the stomach is empty, you won't always get aspirate. Second, there's such a small difference in the pH of gastric vs respiratory secretions (gastric is approx 4 and respiratory approx 5.5) that the results may be confused. Plus, if your patient is on a stomach acid blocker or certain other meds, it will interfere with your pH. Third, try getting a hospital to actually buy pH test strips for gastric contents. If you inject air into the tube and listen in the stomach, you're going to hear it. It could still mean the tube is in the esophagus, but that's where tube length comes into play. And really, of the patient is at all alert and has a tube in their lungs- you're going to know it.

Oh yeah, I know that for sure. I'm not saying I disagree with you, I'm just saying that I know things vary far from what you're taught from what actually happens in the real world. That's why I was just curious as to whether or not checking for a residual volume is one of these lessons from school that isn't practiced or if it should be and the nurses I work with just don't.

[Esme12, ASN, BSN, RN]

Welcome to AN! The largest online nursing community!

Those nurses should be checking for residuals if those patients are getting feedings. They should also be "verifying" position by auscultation at least once a shift. Usually a CXR is done to verify placement especially if the patient is going to be fed. Checking the PH of the "contents"/drainage is not a reliable test especially if the patient had aspiration of gastric contents in the field. As Ashley said if the patient is on certain meds it would effect the resulting PH. I have always verified placement prior to instilling ANY meds down the NGT AND verified placement upon returning from testing as things move when a critical patient is transported for testing.

If the patient is awake....as Ashley said.....it is usually pretty clear when you are in the lung by the patients behavior of coughing, choking, and difficulty breathing.

I hope this helps. :paw: