Which of the following is the cardinal sign of pyloric stenosis?

Combined AIIMS - 2020 (Jodhpur, Bhopal, Patna, Raipur)

Child Health Nursing (Pediatrics)

Easy

Appeared in: Combined AIIMS - 2020 (Jodhpur, Bhopal, Patna, Raipur)

Explanation

Hypertrophic pyloric stenosis is a condition where the pylorus, the stomach's outlet, thickens and obstructs the passage of food.
This obstruction leads to forceful, non-bilious vomiting, which is the hallmark or cardinal sign of the condition.
The vomiting is described as 'projectile' because the stomach contracts powerfully to overcome the blockage, ejecting contents with force.
Infants with this condition are typically hungry immediately after vomiting because the feed never reached the intestines for absorption.

Option B: Fever is a sign of infection or inflammation, which is not the primary mechanism of pyloric stenosis. Pyloric stenosis is a structural, muscular problem, not an infectious one.
Option C: Diarrhea is not a feature of pyloric stenosis. Because food is blocked from entering the intestines, there is a reduction in stool volume.
Option D: While constipation can occur in pyloric stenosis due to the reduced amount of food reaching the intestines, it is a secondary consequence, not the primary or cardinal sign. The most dramatic and defining symptom is the vomiting.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Identifying the cardinal sign of hypertrophic pyloric stenosis as background academic context rather than a clinical decision trigger.
Recognizing projectile vomiting as a potential sign of pyloric stenosis is critical for early diagnosis and intervention, preventing severe dehydration and electrolyte imbalances.
Nursing priorities include assessing for signs of dehydration (e.g., sunken fontanelle, dry diapers, poor skin turgor), monitoring electrolytes, and preparing the infant and family for potential surgery (pyloromyotomy).
What if? If the vomiting were bilious (greenish), it would suggest an obstruction distal to the ampulla of Vater (e.g., duodenal atresia, malrotation), which is a different and often more urgent surgical emergency.

How to Approach the Question

First, identify the core concept in the question stem: 'cardinal sign of pyloric stenosis'. 'Cardinal sign' means the most important or defining symptom.
Recall the pathophysiology of pyloric stenosis: a thickening of the pyloric muscle causes gastric outlet obstruction.
Think through the consequences of this obstruction. If food cannot leave the stomach, what will happen? The stomach will try to empty itself forcefully.
Evaluate the options based on this pathophysiology. 'Projectile vomiting' directly results from the forceful stomach contractions against a blocked outlet.
Eliminate the other options. Fever points to infection. Diarrhea is unlikely with an obstruction. Constipation is a possible secondary effect but not the primary, defining sign.

Concept Tested & Keywords

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