Which symptom is most characteristic of pyloric stenosis and helps distinguish it in infants from other gastrointestinal anomalies?

Appeared in: NCL (Northern Coalfields Limited)-NO

Explanation

Projectile vomiting is the classic, hallmark sign of hypertrophic pyloric stenosis (HPS).
The vomiting is forceful and non-bilious (contains no bile) because the obstruction is at the gastric outlet, proximal to the entry of the bile duct into the duodenum.
This symptom occurs due to the progressive thickening (hypertrophy) of the circular muscle of the pylorus, creating a gastric outlet obstruction.
Despite vomiting, the infant typically remains very hungry and wants to feed again immediately, a key distinguishing behavior.

Option A: Abdominal distension is a non-specific sign and is more characteristic of lower intestinal obstructions.
Option B: Infants with pyloric stenosis typically pass meconium normally. Delayed meconium passage is the cardinal sign of a different condition.
Option D: Rectal bleeding is not a feature of pyloric stenosis. The issue is an obstruction, not a bleed.

Visual 1: Anatomical Diagram - A cross-section of the stomach showing the hypertrophied (thickened) pyloric muscle, contrasting it with a normal pylorus. This helps visualize the cause of the obstruction.
Visual 2: Clinical Sign Photo - An image depicting the 'olive-shaped mass' being palpated in an infant's right upper quadrant, a classic physical finding in pyloric stenosis.

Clinical Relevance

Nursing practice connection: Knowing Clinical manifestations of Pyloric Stenosis helps nurses interpret findings accurately and avoid errors in routine assessment, medication administration, and patient teaching.
A key nursing priority is assessing for and managing dehydration and electrolyte imbalances, specifically hypochloremic metabolic alkalosis, which results from losing large amounts of stomach acid (hydrochloric acid) through vomiting.
Pre-operative care involves correcting fluid and electrolyte deficits with IV fluids. The infant is kept NPO (nothing by mouth), and a nasogastric tube may be inserted to decompress the stomach.
Post-operative care after a pyloromyotomy involves a gradual reintroduction of feedings, starting with small, frequent amounts of clear fluids and advancing as tolerated.

How to Approach the Question

First, identify the core subject of the question: pyloric stenosis in an infant.
Note the keywords 'most characteristic' and 'distinguish.' This tells you to look for the symptom that is most specific to this condition compared to others.
Recall the pathophysiology of pyloric stenosis: a blockage at the stomach's exit. This logically leads to the contents being forcefully expelled back up.
Evaluate each option's association with pyloric stenosis:
Abdominal distension? Possible, but not specific.
Delayed meconium? Classic for Hirschsprung's, not pyloric stenosis.

Concept Tested & Keywords

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