I've noticed a trend of techs and nurses alike on the unit using the Salem sump to clamp off the primary lumen of the NG tube. I remember hearing in nursing school that this was not to be done. I have scoured the internet and textbooks for an answer. Everything says that the Salem sump cannot be clamped externally, which makes sense because this defeats the purpose of that lumen, but they don't mention anything about using the Salem sump to clamp off the primary lumen. Thanks for your help!
Apr 28, '11
Think about why there are two lumens in this tube. Imagine there were just one, connected to suction. When the fluid is all drained, or there is very little accumulating, the suction keeps...sucking, and will pull on the lining of the stomach, resulting in damage to the mucosa. This is, in fact, why that air vent was invented: to break the suction and prevent mucosal damage.
So, knowing that, you can see why you NEVER clamp off the air vent when the main lumen is to suction. You'd be defeating its protective purpose.
There should always be air going down the air vent lumen (listen or feel it with your fingertip briefly), and fluid or at least air coming up the main lumen. If either of those is not happening, it's your job to investigate and fix it.
If fluid is coming up the air vent (a common cause of inappropriate clamping) it's because, well, air isn't going down it, probably because the main lumen is obstructed and there's no suction pulling air down the vent. To figure this out, IF there is no contraindication to moving the tube a bit, irrigate it with a bit of saline and /or withdraw it a few inches, move it up and down. Chances are it will suddenly start to drain and the air will start to go down the air vent. You can push a little air down the vent to clear it. When you have it draining properly, re-secure it.
Be prepared to do this often. These things will occur regularly. Ignoring them, defeating the safety feature of the tube, or just saying the heck with it is risky for your patient and defeats the purpose of the drain being there in the first place. There's a reason it's there: make sure it does what it should do.
If you don't clear the main lumen AND you have clamped the air vent (because it's making a mess on the pillowcase) you now have NO suction to the stomach, and when enough fluid builds up the patient can aspirate. This IS dangerous.
Last edit by nurseprnRN on Apr 28, '11
: Reason: addition
Apr 28, '11
by Esme12, ASN, BSN, RN Senior Moderator
Clamping off the port defeats the puprpose of using the Salem sump. Many people clamp this off because of back flow. Sometimes the back flow of gasrtic contents up the "blue" side is because of insufficient suction or the use of intermittant suction. There is a "anti-reflux" valve that should be used on the "blue" vent side.......I have seen some places that don't buy the valve because like everything else....it costs money.......very little money....but money none the less. Clamping it won't "hurt the patient" per se although there has been documentation that the use of a "Salem" NGT causs less trauma to the stomach lining.
a. The Levin Tube.
The actual tubing is referred to as lumen. The Levin tube is a one-lumen nasogastric tube. The Salem-sump nasogastric tube is a two-lumen piece of equipment; that is, it has two tubes. The Levin tube is usually made of plastic with several drainage holes near the gastric end of the tube. There are graduated markings on the lumen so that you can see how far you have inserted the tube into the patient. This nasogastric tube is useful in instilling material into the stomach or suctioning material out of the stomach.
b. The Salem-Sump Tube.
This nasogastric tube is a two-lumen piece of
equipment. It has a drainage lumen and a smaller secondary tube that is open to the atmosphere. The major advantage of this two-lumen tube is that it can be used for continuous suction. The continuous airflow reduces the frequency of stomach contents being drawn up into the whole of the lumen which is in the patient's stomach.
Last edit by Esme12 on Apr 28, '11