Enteral feeding tubes and home enteral nutrition — formative SAQs

SAQ 1 — The child with cerebral palsy referred for a gastrostomy (20 marks, ~15 minutes)

A four-year-old with severe cerebral palsy has faltering growth despite maximised oral feeding and an unsafe swallow on a videofluoroscopic swallow study. Mealtimes last over an hour and end in a wet cough. The family and the multidisciplinary team agree that long-term enteral feeding is needed. [8]

Questions

1. Which enteral access device is most appropriate, and why is a nasogastric tube not the long-term choice? (5 marks) [1]
2. Outline the pre-gastrostomy assessment, including the reflux and nutritional evaluation. (5 marks) [8]
3. Describe the device options (percutaneous endoscopic gastrostomy versus low-profile balloon button) and when conversion between them occurs. (5 marks) [1] [10]
4. Outline the home enteral nutrition programme you would build for this family. (5 marks) [8]

Model answer (must-hit)

1. The appropriate device is a gastrostomy, because feeding is expected to last well beyond four to six weeks. A nasogastric tube is the short-term choice for feeding under four to six weeks; it dislodges, irritates the nose and requires repeated verification, so it is not the long-term answer for a child needing months to years of non-oral feeding. [1]
2. The pre-gastrostomy assessment plots weight, height and head circumference to quantify the nutritional deficit, assesses reflux and aspiration clinically and with studies where indicated (because uncontrolled reflux may change the choice to a post-pyloric tube or prompt an anti-reflux procedure), checks coagulation and full blood count before the procedure, and confirms the indication and consent with the family. [8]
3. A percutaneous endoscopic gastrostomy is placed endoscopically with an internal bumper and external flange; a low-profile balloon gastrostomy button sits flush on the abdominal wall, retained by a water-filled balloon, and is preferred for cosmesis and concealment. A PEG is commonly converted to a button once the tract has matured, around six to twelve weeks, and the button is exchanged at the bedside when the balloon fails or the child outgrows the stem. [1] [10]
4. The home programme rests on trained carers who can run the feed, look after the stoma and recognise the blocked, dislodged or infected tube; reliable supplies of formula, giving sets and a spare device; regular growth and micronutrient monitoring by the dietitian and paediatrician; and a clear written emergency plan with contacts, so that the family can manage the routine and the common problems at home. [8]

SAQ 2 — The nasogastric tube whose pH is 6.5, and the dislodged gastrostomy (20 marks, ~15 minutes)

A two-year-old has just had a nasogastric tube passed on the ward for short-term nutrition after surgery. Gastric aspirate is obtained but the pH strip reads 6.5; the child is not on acid suppression. Separately, a six-year-old with a long-standing percutaneous endoscopic gastrostomy is brought in with abdominal pain and a tube through which feed will not run. [4]

Questions

1. What is the safest next step before feeding down the nasogastric tube, and what is the accepted bedside pH threshold for gastric confirmation? (5 marks) [4]
2. Name two methods of nasogastric tube verification that are unreliable and must not be used as sole confirmation. (3 marks) [1]
3. What is the most likely diagnosis in the child with the non-functioning gastrostomy, and how is it managed? (6 marks) [1]
4. A child's low-profile balloon button falls out at home. What is the time-critical advice, and why? (6 marks) [1]

Model answer (must-hit)

1. The safest next step is to confirm tube position by chest or abdominal X-ray before feeding, because a pH above 5.5 is not acceptable as sole confirmation. The accepted bedside threshold for gastric confirmation is aspirate pH of 5.5 or below (the NOVEL Project standard); the film should show the tube tip below the diaphragm within the stomach. [4]
2. The auscultatory whoosh test (injecting air and listening over the stomach) and judging position by the colour or appearance of the aspirate are both unreliable and must not be used as sole confirmation. [1]
3. The most likely diagnosis is buried bumper syndrome, in which the internal bumper of the percutaneous endoscopic gastrostomy migrates into and erodes through the gastric wall, so feed cannot pass. It is confirmed endoscopically and managed by endoscopic or surgical removal of the buried tube and replacement; repeatedly flushing will not help. [1]
4. The tract must be kept patent by prompt replacement with a suitable Foley catheter or spare device, because a mature gastrostomy stoma can close within hours and losing the tract turns a simple problem into a surgical one. If the tube cannot be replaced or the child develops peritonism, intraperitoneal leak is suspected and the child needs nil by mouth, intravenous fluids and antibiotics, urgent imaging and surgical review. [1]