Given below are two statements:Statement I: Hypertrophy of circular muscle of the pylorus causes narrowing of the pyloric canal.Statement II: Metabolic Alkalosis and Electrolyte imbalance Noted in Babies with Hypertrophic pyloric stenosis.Choose the correct answer:

1. A

   Statement I is incorrect but Statement II is correct

2. B

   Statement I is correct but Statement II is incorrect

3. C

   Both Statement I and Statement II are incorrect

4. D

   Both Statement I and Statement II are correct

Appeared in: BHU NO - 12 April 2024

Explanation

• Both statements are correct, accurately describing the primary pathology and resulting metabolic disturbances of hypertrophic pyloric stenosis (HPS).
• Statement I is correct because HPS is fundamentally caused by the hypertrophy (thickening) of the pyloric sphincter's circular muscle, which physically narrows the gastric outlet.
• Statement II is correct because the obstruction described in Statement I leads to forceful vomiting. This vomiting causes a significant loss of stomach acid (hydrogen and chloride ions), resulting in the classic finding of hypochloremic metabolic alkalosis and associated electrolyte imbalances like hypokalemia.

Why Other Options Were Wrong

• Option A: This option is incorrect because Statement I is a correct description of the fundamental pathology of HPS.
• Option B: This option is incorrect because Statement II correctly identifies the well-documented metabolic consequences of the persistent vomiting seen in HPS.
• Option C: This option is incorrect because both statements are factually accurate and represent the core concepts of HPS.

Related Visual

Clinical Relevance

• Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Pathophysiology and metabolic consequences of hypertrophic pyloric stenosis (HPS) as background academic context rather than a clinical decision trigger.
• Nurses must recognize the classic signs of HPS: projectile non-bilious vomiting in an infant (usually 3-6 weeks old), persistent hunger after vomiting, visible peristaltic waves across the abdomen, and a palpable olive-shaped mass in the right upper quadrant.
• Pre-operative nursing care is critical and focuses on correcting dehydration and electrolyte imbalances (especially hypochloremic metabolic alkalosis) with IV fluids. Surgery (pyloromyotomy) is delayed until the infant is metabolically stable to reduce anesthetic risks.
• Post-operative care involves careful reintroduction of feedings, monitoring for continued vomiting (which can occur initially due to edema), and assessing for signs of infection at the surgical site.

How to Approach the Question

• First, analyze the question format. It presents two separate statements and asks you to evaluate their accuracy individually and in combination.
• Evaluate Statement I: Recall the definition of hypertrophic pyloric stenosis. 'Hypertrophy' means enlargement, and 'stenosis' means narrowing. The statement says muscle hypertrophy causes narrowing of the pyloric canal. This aligns directly with the definition of the condition.
• Evaluate Statement II: Consider the primary symptom of HPS, which is forceful vomiting. Think about what is being lost in the vomitus (stomach acid - HCl). Loss of acid leads to an alkaline state in the blood (metabolic alkalosis) and loss of electrolytes (chloride, potassium). This confirms Statement II is a known consequence.
• Combine the evaluations. Since both Statement I and Statement II are correct, select the option that reflects this conclusion.
• The image provided serves as a visual confirmation for Statement I, showing the thickened muscle constricting the pyloric canal.

Concept Tested & Keywords

• Concept Tested: Pathophysiology and metabolic consequences of hypertrophic pyloric stenosis (HPS).
• Stem keywords: Hypertrophy, circular muscle, pylorus, pyloric canal, Metabolic Alkalosis, Electrolyte imbalance, Hypertrophic pyloric stenosis
• Lead-in keywords: Choose the correct answer

Question ID

Q0rAlOcY0E8-n-9AV7lurE

Copy ID

Reference Book

E6 Nelson Textbook of Pediatrics(2024) — Volume 2 pp. 58-60, 59-61