G/GJ tubes: How to change the balloon G tube and check tube placement

What are feeding tubes?

Gastrostomy tubes (G tubes), combination G/GJ and gastrojejunostomy tubes (GJ tubes) are feeding devices. A G tube gives liquid nutrition, medication and other fluids directly into the stomach. A GJ tube gives liquid nutrition, medication and other fluids directly into the small intestine (the jejunum). Both G tubes and GJ tubes are placed through a small opening in the stomach. This opening is called a "stoma". The tunnel from the outside of the body to the stomach is called the "tract".

Changing the balloon G tube

Primary balloon G tubes (i.e., surgical tubes) should not be changed in the first 8 weeks from insertion. These instructions do not apply to GJ tubes or combination G/GJ tubes.

Supplies

• new balloon G tube
• soap
• warm water
• washcloth
• sterile or distilled water
• five syringes (two 5-mL slip tip syringes and three syringes that fit the feeding extension – either slip tip or ENFit)
• water-based lubricant or jelly
• feeding extension set (for low-profile G tubes)
• pH strips and colour reference guide

Procedure

1. Wash your hands with soap and water and prepare your equipment and supplies.
2. Into one slip tip syringe, draw up the amount of water recommended by your health-care team to fill the balloon of your child’s tube. Draw 5 mL of water into another syringe that fits the feeding extension to flush the tube. Leave the other three syringes empty. You will use these to remove the old water from the balloon and check the pH.
3. Prepare your washcloth with soap and water on one half of the cloth and non-soapy water on another part.
4. Confirm the placement of the balloon G tube by checking the pH of the gastric contents, as described below. This will give a baseline assessment for gastric aspirate before removing the G tube.
5. Remove the sterile or distilled water from the balloon of the old G tube using one of the empty slip tip syringes. Throw the water and syringe away.
6. Remove the old G tube. It is normal for the inner part of the tube to be brown or black. This is caused by acidic stomach contents. Throw away the old tube.
7. This is a great time to assess the stoma for any changes, such as redness, drainage, rash, or hypergranulation tissue. Wash the stoma with soap and water and rinse it with non-soapy water. Then let it air dry.
8. Lubricate the tip of the new balloon G tube and, at a slight angle, insert it into the stoma, following the existing tract. The tube may be slightly resistant, so it is OK to exert light force. Try to time insertion with when your child breaths in, as they are most relaxed at that time.
9. Once the tube is in place, check that the tube is in the stomach by checking the pH as described below. The tube is in the stomach if you get a pH of less than 6.0 and/or the appearance of the gastric contents is similar to the gastric contents from pre-procedure.
10. Once you know that the tube is in the stomach, inflate the balloon with the amount of sterile or distilled water you usually put in.
11. For non low-profile balloon tubes, gently pull the tube until you feel resistance. This indicates that the balloon has reached the inside of the stomach wall. Adjust the outer disk so that it sits snug against the skin.
12. Flush the tube with 5 mL of water. If your child has a low-profile tube you can use the feeding extension to do this.
13. You may now use the tube for feeding and medications.

Checking that the newly changed balloon tube is in the right spot

Before inflating the balloon, flushing the tube, or using the newly changed tubes for feeds and medications, you will need to check that it is in the stomach by checking the pH of the contents that are pulled from the tube.

How to check the pH

You will need:

• one empty slip tip syringe
• the feeding extension set for a low-profile balloon G tube
• pH strips
• pH colour reference guide

What to do:

1. Once you have inserted the new tube, insert the empty syringe into the feeding extension feeding (for a low-profile balloon G tube) or directly into the tube’s feeding port and pull back a small amount of stomach contents. If you cannot get stomach contents, move your child side to side or sit them up while holding the tube in place.
2. Empty the stomach contents from the syringe onto the pH strip.
3. Compare the colours on the pH strip to the colours on the reference guide.

If the pH is less than 6.0, this means the tube is in the stomach and you can flush the tube and use it for feeding and medications.

If the pH is 6.0 or higher the tube may not be in the stomach. Medications and recent feedings can affect the pH. If your child recently had medications or feeds and their stomach contents look like the photos in the video, you may continue to use the tube. If you get a high reading and your child has not had recent feeds or medications, do not use the tube and check the pH again one hour later.  If the reading is still 6.0 or higher, do not use the tube and contact your G tube specialist during business hours or go to the Emergency Department after hours to have the position checked by fluoroscopy.t. In the meantime, you can tape your child’s tube to their stomach as shown in the photo above.