Projectile vomiting is classical feature of?

SJH Nursing Officer - 2019

Child Health Nursing (Pediatrics)

Easy

Appeared in: SJH Nursing Officer - 2019

Explanation

Pyloric stenosis is characterized by hypertrophy (thickening) of the circular muscle of the pylorus, which is the outlet of the stomach.
This thickening creates a gastric outlet obstruction, preventing stomach contents from passing into the small intestine.
The buildup of pressure from feeding against the obstruction results in forceful, non-bilious, projectile vomiting.
Infants with pyloric stenosis are typically hungry immediately after vomiting and may show signs of dehydration and weight loss.
The classic presentation is in infants between 2 and 8 weeks of age.

Option A: Duodenal atresia, a blockage in the first part of the small intestine, typically causes bilious (green- or yellow-stained) vomiting because the obstruction is distal to where bile enters the intestine.
Option C: Congenital megacolon (Hirschsprung disease) primarily presents with failure to pass meconium in the first 48 hours of life and abdominal distention. Vomiting can occur, but it is a later sign and is typically bilious, not the classic projectile type seen in pyloric stenosis.
Option D: Appendicitis is inflammation of the appendix. While it causes nausea and vomiting, the vomiting is not typically projectile. The primary symptom is abdominal pain that usually precedes the vomiting. It is also very rare in infants.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Differential diagnosis of vomiting in infants, specifically identifying the cause of projectile vomiting as background academic context rather than a clinical decision trigger.
A nurse's primary role is the accurate assessment and reporting of vomiting characteristics in infants. Differentiating between non-bilious projectile vomiting and bilious vomiting is critical for timely diagnosis and intervention.
For pyloric stenosis, nurses manage pre-operative care, focusing on correcting dehydration and electrolyte imbalances (hypochloremic, hypokalemic metabolic alkalosis) to ensure the infant is stable for surgery (pyloromyotomy).
Post-operatively, nurses play a key role in re-introducing feeds, monitoring for persistent vomiting, and educating parents on wound care and signs of complications.

How to Approach the Question

First, identify the key clinical sign in the question stem: "projectile vomiting".
Recall the classic presentations of the gastrointestinal disorders listed in the options, particularly as they manifest in infants.
Associate "projectile vomiting" with its hallmark condition. Think about the pathophysiology: what would cause such forceful expulsion of stomach contents?
Evaluate each option. Pyloric stenosis causes a physical blockage at the stomach outlet, leading to a pressure buildup that results in projectile vomiting.
Rule out the other options by recalling their distinguishing features: Duodenal atresia causes bilious vomiting. Congenital megacolon's primary sign is failure to pass meconium. Appendicitis presents with pain first and is rare in this age group.
Confirm the selection of Pyloric stenosis as the condition most classically defined by projectile vomiting.

Concept Tested & Keywords

Concept Tested: Differential diagnosis of vomiting in infants, specifically identifying the cause of projectile vomiting.
Stem keywords: Projectile vomiting, classical feature
Lead-in keywords: is
Negative lead-in flag: false

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E6 Pathology- ROBBINS & COTRAN PATHOLOGIC BASIS OF DISEASE 10TH Ed p. 756-758

E6 Nelson Textbook of Pediatrics(2024) — Volume 2 pp. 59-61, 63-65