What is a cardinal sign and common symptom of Hypertrophic Pyloric Stenosis?

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AIIMS NORCET 8 Prelims Memory Based Paper 2025

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Answer 1

Correct Answer: Projectile non-bilious vomiting and metabolic alkalosis

Rationale:

Hypertrophic Pyloric Stenosis (HPS) is a condition in infants where the pylorus (the opening from the stomach to the small intestine) becomes abnormally thickened, leading to obstruction of gastric emptying.
Projectile non-bilious vomiting is the cardinal sign of HPS. This occurs because the thickened pylorus prevents food from moving from the stomach to the intestines. Vomiting is non-bilious because the obstruction is proximal to the duodenum, where bile would normally be mixed with gastric contents.
Metabolic alkalosis is a common symptom of HPS. Repeated vomiting leads to loss of stomach acid (hydrochloric acid), resulting in an imbalance in acid-base levels and causing alkalosis.
Other associated symptoms include visible gastric peristalsis (wave-like stomach movements) and failure to thrive due to inadequate nutrition intake.

Additional Information:

HPS typically presents in infants between 2-6 weeks of age and is more common in males. Diagnosis is confirmed using ultrasound imaging, which reveals the thickened pyloric muscle.
Treatment involves surgical intervention, specifically a pyloromyotomy, which relieves the obstruction by splitting the thickened pyloric muscle.

Explanation of Other Options:

Bilious vomiting and diarrhea

Rationale: Bilious vomiting (vomit containing bile) indicates an obstruction distal to the duodenum, not proximal as seen in HPS. Diarrhea is not a typical symptom of HPS, as the obstruction prevents food from reaching the intestines.

Bloody stools and abdominal distension

Rationale: Bloody stools and abdominal distension are more characteristic of conditions like intussusception or necrotizing enterocolitis. These symptoms are not associated with HPS.

Constipation and dehydration only

Rationale: While dehydration may occur due to fluid loss from vomiting, constipation is not a defining feature of HPS. The primary symptom is vomiting, not bowel movement abnormalities.

Conclusion:

Projectile non-bilious vomiting and metabolic alkalosis are the hallmark signs and symptoms of Hypertrophic Pyloric Stenosis. Early recognition and surgical treatment are crucial for preventing complications and ensuring recovery.