Which of the following is a key clinical sign of congenital hypertrophic pyloric stenosis in infants?

NORCET 9 Mains - 2025

Child Health Nursing (Pediatrics)

Easy

Appeared in: NORCET 9 Mains - 2025

Explanation

The hallmark sign of CHPS is non-bilious, projectile vomiting, which occurs shortly after feeding.
The obstruction is at the pylorus, proximal to the ampulla of Vater where bile enters the duodenum, hence the vomitus is non-bilious (contains no bile).
A firm, mobile, olive-shaped mass can often be palpated in the epigastrium or right upper quadrant, which is the hypertrophied pyloric muscle.
Infants with CHPS are typically hungry immediately after vomiting and eager to feed again (a 'hungry vomiter').

Option A: Bile-stained vomitus indicates an obstruction distal to (after) the ampulla of Vater, allowing bile to mix with gastric contents. In pyloric stenosis, the blockage is proximal to this point.
Option C: These signs are more characteristic of a lower or distal bowel obstruction, not a gastric outlet obstruction like pyloric stenosis. Vomiting is the predominant symptom in pyloric stenosis, not significant distension or constipation initially.
Option D: Diarrhea is the primary symptom of gastroenteritis or other infectious bowel diseases. Pyloric stenosis is a mechanical obstruction that causes vomiting and can lead to constipation due to decreased stool volume.

Visual 1: Diagram: Anatomical illustration showing the location of the hypertrophied pyloric sphincter between the stomach and the duodenum, highlighting why the obstruction is proximal to bile entry.
Visual 2: Illustration: Depiction of an infant experiencing projectile vomiting to help visualize the forcefulness described.
Visual 3: Ultrasound Image: An abdominal ultrasound image showing the thickened pyloric muscle, often referred to as the 'target' or 'cervix' sign, which is the gold standard for diagnosis.

Clinical Relevance

Nursing practice connection: Knowing Clinical manifestations of congenital hypertrophic pyloric stenosis (CHPS) helps nurses interpret findings accurately and avoid errors in routine assessment, medication administration, and patient teaching.
Nurses must recognize the signs of CHPS early to prevent severe dehydration, electrolyte imbalance (hypochloremic, hypokalemic metabolic alkalosis), and malnutrition.
Accurate assessment of vomiting (color, force, timing) is critical. Differentiating between bilious and non-bilious vomiting is a key nursing responsibility that points to the location of the obstruction.
What if? If the infant's vomitus was green-tinged (bilious), it would be considered a surgical emergency suggesting malrotation with volvulus, requiring immediate investigation, not the more scheduled correction for pyloric stenosis.

How to Approach the Question

First, identify the core condition in the question: congenital hypertrophic pyloric stenosis.
Recall the pathophysiology: this is a gastric outlet obstruction. Think about the anatomy - what is just beyond the stomach's outlet (pylorus)?
The duodenum is next, and bile enters the duodenum. Therefore, an obstruction at the pylorus means stomach contents are vomited before they can mix with bile.
This logic immediately points to 'non-bilious' vomiting as a key feature, helping to eliminate options with 'bile-stained' vomitus.
Evaluate the remaining options based on classic signs. 'Projectile' vomiting and a palpable 'olive' mass are the textbook triad for CHPS.

Concept Tested & Keywords

Concept Tested: Clinical manifestations of congenital hypertrophic pyloric stenosis (CHPS).
Stem keywords: congenital hypertrophic pyloric stenosis, infants, key clinical sign
Lead-in keywords: Which of the following
Negative lead-in flag: false

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