Small Bowel Obstruction (SBO) case study

hodgieRN · Nov 5, 2012

Sure. The obstruction will obviously block anything going down, so you can have variations in output b/c everything is coming back up. 575 ml is a lot, but there's other factors that can add to it. For example, the GI tract can become hyperactive and start spilling mucous or fluid. Pt's with SBO can become dehydrated, so once they re-hydrate with IV fluids, the amount of fluid production can increases b/c its available. The stomach can secrete an impressive amount on it's own. Interestingly, NG suctioning itself can cause a hyper-production of fluid (more rare than common), meaning the stomach can secrete what you suction out. The gallbladder can overproduce bile, which can add to your output.

But, a sudden increase in output signifies a change, so you should report that to the doc and keep a close eye on it. Make sure you are looking at the contents. If it goes from green to black or red, it could mean a GI bleed. All that NG loss can lead to electrolyte imbalance like potassium, magnesium, and sodium or dehydration. The good thing is that your pt had a decrease from the 575.

In general, the output can vary. I had a pt that lost liters per day through the NG. If I left it on medium continuous suctioning, it just kept coming out. It was like 600-800 ml every 4-6 hrs. The fluid kept spilling into his GI tract.

thechamster · Nov 6, 2012

Thanks for the help!! I asked my instructor about it and she said she's not looking for any specific number (here I am going crazy trying to find an approximate number) but the fact that it changed from a sudden 575 to 250/2hr. IS this change abnormal? Is there a possibility that there is something occluding the NG tube? Maybe change in position?

Esme12, ASN, BSN, RN · Nov 7, 2012

I think you need to look at the amount that the NGT drained not how much drained when. Just by the patient moving the NGT can move and get "sucked up" on the side of the abdomen and suddenly move and dump a huge amount. The issue is how will the loss of this volume affect the patient. What can this do the the homeostasis of the body......will it affect the acid base balance? Will it affect electrolytes? Does it affect the fluid balance/hydration of the patient? Is the loss of 850cc's of fluid harmful to the patient? Can an IV at 100cc/hr replace this loss?

What does the loss of this VOLUME of fluid have on the body?

hodgieRN · Nov 7, 2012

Checking for NG occlusion is pretty straight forward. As long as it flushes and aspirates easily, the tube can be considered patent. In other cases that don't include obstruction, a decrease in output can signal proper draining of the GI tract. As Emse12 stated, positioning can alter output. I wouldn't say technically say it's abnormal, but while in school, it's safer to think it's abnormal or at least a change in order to get the point across. However, it is common for NG's to suction and/or stick to the gastric wall, making it seem as if there's an occlusion. If you ever get report and the nurse says an NG has zero output, make sure it's not on constant suction or check the intermittent to see there is no pressure. Those modules stop working sometimes or the person who changed the canister left the "ortho" port open, leaving zero suction to the NG.

nurseprnRN, BSN, RN · Nov 12, 2012

To really understand this question it's very important to understand what that NG tube, probably a Salem sump tube with the little blue pigtail, is, how it works, and why we care.

Before Salem sump tubes were invented, all we had were single-lumen tubes to suck out stomach contents. What's the problem there, you say? Well, if suction has removed all liquid stomach contents and it keeps sucking, what you get are little punch biopsies of the stomach mucosa, and this is not a good thing. So, some clever person (perhaps a Salem witch) figured out that if there were a way for the suction to have something else to suck on, to break the vacuum in the stomach, like air (and any other fluid that happened to accumulate too, of course), then this would protect the stomach from having vicious little hickies from suction at the eyelets down below and bleeding and such.

The air vent on the Salem sump is that solution. Air should always be going down the blue lumen. How do you know if that's happening? Well, you can put your ear near it and hear it, or put your thumb over the end of it briefly and feel suction there, but the best way to see is that there should always, always, always be air bubbles coming up the main lumen to your suction cannister. Now you know something important: if it isn't, there's hickifying going on down there, and that's a bad thing.

The air vent lumen should always be patent (open) all the way down. If it isn't you can do a couple of things (after you have determined that some fool has not turned off your suction outlet). One is to untape the tube and pull it back an inch or so, and then put it back. You can also push some air (not fluid) down the blue lumen. Yes, you may have to do this all dang day long, but you will often be rewarded by a gush of gastric goo, which is what you wanted anyway.

What's going on if there is no air coming up the main lumen and there's goo coming out of the air vent? Well, (assuming your suction is still turned on and plugged in properly) your main lumen is probably occluded and goo has nowhere else to go but up the air vent, and you should probably think about replacing the whole tube. But before you do that, if it's not otherwise contraindicated, shoot some NS down both lumens, and follow that with air down the air vent lumen. See if that doesn't get things moving properly. If not, do the wiggling thing as above. If that doesn't work, get the ok to replace it (or have the physician or np come and replace it).

Some Salem sumps come with little plugs in the blue lumen. They're supposed to be one-way valves to allow air entry and prevent backflow but they don't always really do a great job of it. If you can still verify air entry past that plug and bubbles are going up the main lumen, it's fine. But if it's gotten grubby and acts like an actual plug, get rid of it, or what you have is now a gastric mucosa-grabbing single-lumen tube.