1. Gastrostomy Tubes: A Primer Tamara Simon, M.D. Assisted by Kim Washington, CPNP Special Care Clinic July 2004, August 2005

2. Purpose Allow for enteral feedings for children with: –swallowing dysfunction –severe gastroesophageal reflux –esophageal atresia –esophageal burns or strictures –craniofacial abnormalities –chronic malabsorption –failure to thrive

3. Procedure Placed using endoscopic technique –Done by GI or pediatric surgery –Placed with percutaneous endoscopic technique: Stomach and anterior abdominal wall punctured Feeding catheter is inserted Gastrocutaneous fistula forms around gastrostomy tube held in placed by internal and external bumper guards Sutures, if placed, hold the tube in the stoma Placed in conjunction with Nissen –Requires pH probe +/- upper GI series –Done by pediatric surgery

4. Procedure (continued) Gastrocutaneous fistula matures between 2- 4 weeks and up to 3 months after creation Replacement with low profile button after stoma matures –Balloon tip (MIC-Key) –Mushroom tip (Bard) –Collapsible wing tip

5. MIC-Key Balloon-tip Gastrostomy Button Pros: No venting needed Easier to change Cons: More mobile portion between button and balloon Develops leaks

6. Bard mushroom tip Gastrostomy Button with Obdurator Pros: Sturdier construction Used in PEG placement due to size Cons: Venting apparatus needed Difficult to change Requires training

7. Complications Wound infection Hemorrhage Mucosal injury Gastrostomy tube dysfunction: –Obstruction of tube –Dislodgement of tube –Cracking or fracture of tube

8. Complications (continued) Leakage around wall Granulation tissue formation Migration of tube Fistula formation

9. Wound infection Seen in 20% of patients Purulent, bloody, cellulitic skin; yellow-brown discharge without signs of infection is normal Avoid occlusive dressings because moisture accumulates and predisposes to infection Usually superficial and can be treated easily –Clean with region with antiseptic –Apply topical antibiotics Cellulitis may be occasionally be present –Systemic antibiotics are required –Vigilance for necrotizing fasciitis

10. Hemorrhage Usually small amount of self-limited bleeding at the time of placement Bleeding remote from the time of placement may indicate ulcers or erosion of the gastric mucosa

11. Mucosal injury Range from erosions of gastric mucosa (gastritis) to perforation of stomach Can occur in gastric wall opposite the gastrostomy tube

12. Gastrostomy tube dysfunction: Obstruction of tube Most common cause of tube malfunction (14%) Caused most often by formulas coagulating in acidic pH –Avoid mixing medication with formula (some meds are acidic) –Crushed pills, especially sustained release, commonly cause obstruction –Proteinaceous material implicated Can be prevented by flushing before and after feeds and medication administration

13. Gastrostomy tube dysfunction: Obstruction of tube Attempt to flush gently with 5 ml warm water with 5 ml syringe, instill and pull back up to 5 times Try smaller syringe to create increased pressure If successful, flush tube again to ensure patency If unsuccessful, try solution of pancreatic enzymes (crush Viokase 8 tablet and 325 mg sodium bicarbonate tablet into fine powder, mix with 5 ml warm water, instill in 10 ml syringe, wait 5 minutes Attempt to flush with 5 ml or smaller syringes Can repeat above for 30 minutes

14. Gastrostomy tube dysfunction: Obstruction of tube Other solutions- carbonated liquids, meat tenderizer, and/or milking the tube Then notify GI/surgery that feeding tube cannot be cleared

15. Gastrostomy tube dysfunction: Dislodgement of tube (immature fistula) Immature fistula : < 4 wks post-surgical placement, < 12 weeks post-percutaneous placement –Stoma relies on the apposition of skin and gastric mucosa –Gastric layer closes faster than skin –Almost anything can be used to keep stoma patent –The stomach is not sterile

16. Gastrostomy tube dysfunction: Dislodgement of tube (immature fistula) –Gently place small Foley –However, complications could include detachment of stomach from abdominal wall, development of false tract, peritonitis, pneumoperitoneum, and/or air embolism –If any resistance felt, consult surgery or GI immediately –If necessary, nasogastric tube can be inserted and stoma permitted to close

17. Gastrostomy tube dysfunction: Dislodgement of tube (cont) Mature fistula –Attempt to replace same size and type of tube or button –If size not known, measuring device can be used (consult G tube nurse); use taped Foley catheter left in place if nurse not immediately available

18. Gastrostomy tube dysfunction: Dislodgement of tube (cont) –Original tube or Foley catheter can be inserted to maintain patency until device obtained stoma closes in 24-48 hours If fistula has almost closed, consult surgery/GI and nasogastric tube can be inserted –Place successively larger tubes (Foleys) every 30 minutes to dilate –Do not dilate with hemostat!

19. Gastrostomy tube dysfunction: Cracking or fracture of tube –Remove original Balloon-tip (MIC-Key) - remove after deflating balloon Mushroom or collapsible-wing tip (Bard)- gentle traction or, if necessary, cut tip at external surface of wall and push into stomach for later excretion or removal by endoscopy

20. Gastrostomy tube dysfunction: Replacement of tube –Balloon tip (MIC-Key) Clean site and select proper replacement Test new button by inflating and deflating balloon with water or saline- 360° inflation Lubricate tube with water soluble jelly Gently insert in stoma perpendicular to abdominal wall- 3 cm beyond balloon Reinflate balloon with water or saline (3-5 ml for infants, 5-7 ml for children)

21. Gastrostomy tube dysfunction: Replacement of tube Test placement Apply gentle traction pulling balloon against gastric mucosa Button should lie flat against abdomen

22. Gastrostomy tube dysfunction: replacement of tube –Mushroom and collapsible-wing tips Insert obdurator into open sides of tip to distend tip before placing in stoma With tip distended, tube is inserted into stoma perpendicular to abdominal wall with steady pressure until flush with abdominal wall Once fully inserted, obdurator is removed Test placement Button should lie flat against abdomen

23. Confirming gastric placement Check pH of aspirate (<5) Check color of aspirate If no aspirate obtained, inject 5 ml air and aspirate again Also reposition patient Transpyloric placement (for NG) –Bilious, high pH –Withdraw tube 3-5 cm and recheck Pulmonary placement bilious, high pH –Respiratory distress, serosanguinous aspirate, pH 5-6 –Remove immediately

24. Leakage around wall Occurs in 10% of patients Looks like formula May be caused by: –clogged tube –deterioration of tube- check balloon –stoma that is enlarged due to external traction on the tube May be treated with : –Sorbsan around the site if the stoma is too big –Stoma adhesive powder and Maalox/Aquaphor solution can be used for leakage alone

25. Granulation tissue May accumulate on abdominal wall Bleeds easily, causes discharge, irritation, and discomfort Clean secretions or crusts from site Apply water soluble jelly to normal tissue in 5 cm circle surrounding granulation Silver nitrate stick can be used to cauterize tissue once daily for 7-10 days (up to 3 weeks) until granuloma is gone

26. Granulation tissue Recurrences are frequent Check for prolapse (pinker, regular color) which does not respond to silver nitrate – i.e. doesn’t turn gray Apply Kenalog cream tid for 2 weeks (wait 1 hour if after silver nitrate)

27. Migration of Tube Can migrate down the intestinal tract or up the esophagus Downward migration can cause obstruction or even perforation Upward migration can cause aspiration

28. Further Questions Questioning potential complications? Get a radiologic dye study +/- abdominal radiographs, upper GI series, or endoscopy Consult G tube nurse Consult Kim Washington if Special Care Clinic patient Consult gastroenterologist or surgeon who originally placed G tube

29. References Teoh DL. Tricks of the Trade: Assessment of High-Tech Gear in Special Needs Children. Clinical Pediatric Emergency Medicine. 3(1), March 2002. Washington, K. G Tube Care handout. Joffe, M. Troubleshooting Lines, Tubes, and Catheters. Pediatric Hospitalist Meeting, Denver, July 2005.