G-tube Primer by Dr. Lindsey Armstrong.
Hi, I'm Lindsey Armstrong, a Surgical Critical Care Fellow at Boston Children's Hospital.
Today I'm going to be reviewing a quick G-tube Primer. The objectives for this video are to
define gastrostomy, identify indications for G-tube placement, and identify types of G-tubes.
G-tube Overview.
So what is a G-tube? A G-tube, or a gastrostomy tube, is simply a tube that goes into a
gastrostomy. A gastrostomy is created surgically between the abdominal wall and the stomach.
The G-tube goes into this gastrostomy, and can be used for feeding or decompression.
You may be familiar with children in the hospital that require nasogastric tubes
for feeding or decompression. Children with small bowel obstructions, or ileus, may need
the tube in place so that they can vent their stomach. Or other children that have functional
abdominal tracts may need the tube for feeds, if they can't take all their nutrition by mouth.
When children require these types of tubes on a longer term basis,
they may be candidates for surgically placed gastrostomy tubes. These tubes also serve other
functions, and can be used for procedures, for contrast administration, or for passing dilators
retrograde in the cases of esophageal stricture sometimes seen in kids with esophageal atresia.
Gastrostomy tubes are more advantageous than the NG tube, for multiple reasons. Babies are
known to be nose breathers, so having one less tube in their nose helps them
breathing. The NG tubes are also limited by their size, whereas the G-tubes don't have
to be the size of the patient's nares, so we're able to use much larger tubes
for feeding and decompression, if it's through the abdominal wall than through the nose.
Also the NG tube, if left in place for a while, can cause irritation
to the delicate mucosa of the nose and esophagus. So in this case,
a G-tube is more comfortable and doesn't risk that type of erosion.
If you're called by a nurse about a problem with the G-tube, then there are a few things
that you should know about that tube that will help you address those issues.
Most importantly, you're going to want to know what kind of tube it is, and that refers to the
brand, also the location-- is it in the stomach? The small intestine? Or both, as in a G-J tube?
When the tube was placed, so how many weeks, months, or years ago.
And then also if you can, who placed it. Was it done at this institution, or somewhere else?
Types of G-tubes.
We'll now take a few minutes to review the different kinds of G-tubes.
The first and most common tube is the button, or the tube. Hopefully you're familiar with this
type of tube. As I said, there's two types-- the button, which is a skin level tube, or the tube,
which has more of an extension that you'll see external on the baby or child's abdominal wall.
Both have internal balloons used for fixation, and both can be G or G-J.
The gastrostomy button is a skin level silicone device that has a side access port,
on which you can stick a syringe and inflate or deflate the balloon.
The balloon should be inflated with sterile water only.
The other port is a feeding port, and there is an anti-reflex valve within the tubing
that prevents gastric contents or feeds from coming out the tube, if you don't want them to.
This comes with extension kits, so that the bag doesn't have to be right against the child's
abdominal wall. The extension sets will swivel as the patient moves, so that the patient can change
positions during feeding. The gastrostomy tube with the extender, is a non-skin level silicone
device. It has three ports, one for the balloon as with the button, one for feeds, and one for meds.
There is a round flange, or disk, that is movable along the length of the tubing on the outside of
the child, and this can be used to accommodate any size abdominal girth. You'll simply slide
this down to the patient's abdominal wall until it is flush, to secure the tube externally.
These types of tubes are often used when the patients require more venting or continuous
decompression. The longer tube however, is more susceptible to being pulled on,
which can cause accidental dislodgement. Or consistent tension can actually enlarge
the tract, or the gastrostomy, which could lead to leaking.
The G-J tube is a gastrostomy, and a jejunostomy tube all in one. This is a
button or a tube. The button is a skin level silicone device with a side port, on which
you insert your syringe for balloon inflation and deflation, to hold the tube in place internally.
These other two ports that you'll notice on this button are-- one for the G and one for the J.
The G goes directly into the stomach, and the J port is attached to a longer tube
internally, that will end up ending inside the small bowel.
These also contain anti-reflex valves, and the tubes are radiopaque, which means that
you can see them if you get an X-ray. This is useful in determining their location.
These are often placed in interventional radiology through an existing gastrostomy. So if a child
had a G-tube, but for some reason was unable to tolerate feeds in their stomach anymore,
they might be a candidate for exchange to a G-J tube done by the IR physicians.
These also come with extensions, which can be used on the G port or the J port.
It's important to remember to never give bolus feeds through the J port,
only through the stomach. This is also an advantageous tube because you can
simultaneously feed the small intestine through the J port, while decompressing the stomach.
The alternative to the G-J button is the G-J tube, which is a non-skin level silicone device.
Again with three ports, one for the balloon, one for the stomach and one for the small bowel.
It also has the external disk, which is movable and helps to secure the tube externally. This is
radiopaque, again to help determine the location of the tip of the J port in the small bowel,
and it is most often placed by interventional radiology through an existing gastrostomy.
Moving on to different types of tubes. We have the Bard Button. It is a skin level silicone device,
with a soft radiopaque retention dome instead of a balloon for securement. So the Bard Button
is not inflatable, or deflatable. It has extension kits that go on to the outside,
as does the button with the balloon. And these can be used for feeding or decompression.
The PEG, or the Percutaneous Endoscopic Gastrostomy Tube is a tube that is not placed
surgically, but is placed via endoscopy. The tube is inserted through the mouth,
and then brought out through the skin on the abdominal wall via the Seldinger Technique.
The patient is of course sedated for this procedure.
The tube is different than other tubes you will encounter. It is a polyurethane tube,
and it also has an internal bumper through which the patient's port for feeding or decompression
enters. This stabilizes the tube internally, and then there is an external bumper that will
stabilize it on the external wall. This also comes with adapters and extensions for giving feeds.
The Malecot tube is another form of G-tube that is most commonly seen in smaller babies, as the
internal fixation device is much smaller. So children with
very small stomachs, that maybe a G-button balloon would take up their entire stomach.
This is a little more advantageous. So there's actually room for feeds in the stomach as well.
The internal bumper is a soft flexible bulb that looks almost like a weaved basket,
and it anchors the tube inside the stomach. It is easily pulled out, with really not that much
tension. So it's usually used as a temporary device until another tube can be placed, or the
child is big enough to have a different kind of tube. It comes in latex and latex-free versions,
and does require external securement usually through sutures or some-- a great tape job.
The Foley catheter, while not a common G-tube, can be used for temporary securement. Most commonly,
if your G-tube were pre-existent and were to fall out, if the tube is broken, you can't
find another tube, and need to get something into the gastrostomy to ensure that the track doesn't
close, then a Foley catheter of the same size, or one to two French smaller would be ideal.
This of course is a non-skin level tube. It has an internal balloon that you can inflate with the
ports on the outside. It's of course going to pull out easily. So once you have it in place,
it's important to secure it with tape or with sutures.