A child with congenital megacolon is admitted for surgical correction. The enema should be?

BSF Staff Nurse - 2015

Child Health Nursing (Pediatrics)

Hard

Appeared in: BSF Staff Nurse - 2015

Explanation

Isotonic saline is the safest enema solution for children, especially those with Hirschsprung's disease.
Its osmotic pressure is the same as the body's fluids, which prevents dangerous fluid shifts across the large surface area of the dilated colon.
This avoids complications like water intoxication (from hypotonic solutions) or dehydration and electrolyte imbalance (from hypertonic solutions).
The primary purpose in this context is to decompress the bowel safely before surgery, which isotonic saline achieves by stimulating peristalsis through volume without altering fluid balance.

Option A: An oil enema is a lubricant used to soften hard, impacted stool. It is not effective for the large-volume cleansing and decompression required to prepare a child with megacolon for surgery.
Option B: Soap water enemas are both irritating to the bowel mucosa and hypotonic. The soap can cause chemical irritation and inflammation, while the hypotonic water can be rapidly absorbed by the large, dilated colon, leading to fluid overload and water intoxication.
Option C: Phosphate enemas are hypertonic, meaning they have a higher solute concentration than body fluids. They work by drawing large amounts of water from the body into the bowel. In a child with megacolon who may retain the enema, this can lead to severe dehydration and life-threatening electrolyte disturbances like hyperphosphatemia and hypocalcemia.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Pre-operative management for a child with congenital megacolon (Hirschsprung's disease), specifically the selection of a safe enema solution as background academic context rather than a clinical decision trigger.
A nurse's primary responsibility when administering an enema to a pediatric patient, especially one with Hirschsprung's, is safety. This includes using the correct solution (isotonic saline), correct volume, and monitoring the child closely for signs of complications.
Nurses must monitor for signs of bowel perforation or enterocolitis, which are serious risks in children with Hirschsprung's. Symptoms include fever, abdominal distension, and explosive, foul-smelling diarrhea.
What if? If the patient were an adult with simple constipation and no contraindications, a phosphate enema or even a tap water enema might be considered. However, for a child with a pathological bowel condition, safety protocols are much stricter, and isotonic saline is the standard of care.

How to Approach the Question

First, identify the key elements of the question: the patient is a 'child', the diagnosis is 'congenital megacolon' (Hirschsprung's disease), and the procedure is a pre-surgical 'enema'.
Recognize that 'congenital megacolon' implies a large, dilated bowel that can retain significant amounts of fluid, making the patient vulnerable to fluid and electrolyte shifts.
Evaluate each enema option based on its tonicity (isotonic, hypotonic, or hypertonic) and mechanism of action.
Consider the risks associated with each type of enema in this specific patient population. Hypotonic solutions (tap water, soap suds) risk water intoxication. Hypertonic solutions (phosphate) risk dehydration and electrolyte imbalance.
Select the option that is isotonic, as it will not cause a significant net fluid shift, making it the safest choice for a child with a compromised bowel.
Therefore, an isotonic saline enema is the only appropriate choice.

Concept Tested & Keywords

Concept Tested: Pre-operative management for a child with congenital megacolon (Hirschsprung's disease), specifically the selection of a safe enema solution.
Stem keywords: child, congenital megacolon, surgical correction, enema
Lead-in keywords: should be
Clinical cues: The diagnosis of 'congenital megacolon' in a 'child' is the most critical cue. This points to Hirschsprung's disease, a condition with a high risk for fluid and electrolyte imbalances, making the choice of enema solution critical for safety.

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E6 Nursing Fundamentals Potter Perry 12e Part 6 pp. 42-44, 41-43

E6 Nelson Textbook of Pediatrics(2024) — Volume 1 p. 728-730