Hypertrophic Pyloric Stenosis MCQ Quiz | Pediatric Surgical

Welcome to this specialized multiple-choice quiz on Hypertrophic Pyloric Stenosis (HPS), a critical topic in Pediatric Surgery for MBBS students. This quiz is designed to test your understanding of the etiology, pathophysiology, clinical presentation, diagnosis, and management of HPS. Covering 25 carefully curated questions, this assessment will challenge your knowledge on everything from the classic “olive-like” mass and projectile non-bilious vomiting to the characteristic hypochloremic metabolic alkalosis. After completing the quiz, you can submit your answers to see your score and review the correct responses. For your future reference and study, an option to download all questions with their correct answers in a convenient PDF format is also available. Good luck!

1. What is the hallmark clinical presentation of infantile hypertrophic pyloric stenosis (HPS)?

Bilious projectile vomiting Non-bilious projectile vomiting Chronic diarrhea Failure to pass meconium

2. At what age does HPS typically present?

Within the first 24 hours of life Between 3 to 6 weeks of age After 6 months of age During adolescence

3. What is the classic metabolic derangement seen in an infant with prolonged vomiting from HPS?

Hyperchloremic, hyperkalemic metabolic acidosis Hypochloremic, hypokalemic metabolic alkalosis Normal anion gap metabolic acidosis Respiratory acidosis with metabolic compensation

4. A pathognomonic finding on physical examination for HPS is a palpable:

“Sausage-shaped” mass in the right upper quadrant “Olive-sized” mass in the epigastrium Distended bladder Hepatosplenomegaly

5. HPS is characterized by hypertrophy of which specific muscle layer of the pylorus?

Longitudinal muscle layer Circular muscle layer Muscularis mucosae Oblique muscle layer

6. What is the preferred and most sensitive imaging modality for diagnosing HPS?

Abdominal X-ray Barium upper GI series Abdominal Ultrasound CT scan of the abdomen

7. Which of the following ultrasound findings is most diagnostic of HPS?

Pyloric muscle thickness > 3 mm Pyloric canal length < 10 mm Presence of free fluid in the abdomen Whirlpool sign

8. What is the most crucial initial step in the management of a dehydrated infant diagnosed with HPS?

Immediate nasogastric tube placement for decompression Emergency pyloromyotomy IV fluid resuscitation and correction of electrolyte imbalance Administration of antiemetics

9. Which intravenous fluid is most appropriate for maintenance therapy in a rehydrated infant with HPS awaiting surgery?

5% Dextrose in water (D5W) 0.9% Normal Saline Lactated Ringer’s solution 5% Dextrose in 0.45% Saline with 20 mEq/L KCl

10. The definitive surgical treatment for HPS is known as:

Nissen fundoplication Ladd’s procedure Ramstedt pyloromyotomy Kasai portoenterostomy

11. A Ramstedt pyloromyotomy involves which of the following steps?

Resection of the hypertrophied pylorus Longitudinal incision of the pyloric serosa and muscle, leaving mucosa intact Creation of a bypass from the stomach to the jejunum Transverse closure of a longitudinal pyloric incision

12. What is the most common cause of persistent vomiting after a pyloromyotomy?

Incomplete myotomy Mucosal perforation Gastroesophageal reflux Wound infection

13. Which demographic has the highest incidence of HPS?

First-born females First-born males Premature infants Infants of diabetic mothers

14. Postnatal exposure to which antibiotic has been associated with an increased risk of developing HPS?

Amoxicillin Gentamicin Erythromycin Cefotaxime

15. If a barium upper GI series is performed, what is the characteristic finding for HPS?

“Double-bubble” sign “Bird’s beak” sign “String sign” or “railroad track sign” “Corkscrew” appearance of the duodenum

16. Why is the vomitus in HPS typically non-bilious?

The obstruction is distal to the ampulla of Vater Bile production is decreased in infants The obstruction is proximal to the ampulla of Vater The vomitus consists mainly of saliva

17. Post-operative feeding after a successful pyloromyotomy is typically initiated:

After 24-48 hours Within 4-6 hours Once bowel sounds return, usually after 3 days After a post-operative swallow study confirms no leak

18. The phenomenon of “paradoxical aciduria” in a severely dehydrated HPS patient is caused by:

Renal failure leading to inability to excrete acid Renal conservation of K+ at the expense of H+ ions in the distal tubule Overproduction of lactic acid due to poor perfusion Aldosterone-mediated excretion of bicarbonate

19. A dreaded, though uncommon, intraoperative complication of a Ramstedt pyloromyotomy is:

Hemorrhage from the gastro-duodenal artery Splenic injury Duodenal mucosal perforation Injury to the common bile duct

20. Which of the following conditions is least likely to be in the differential diagnosis for a 4-week-old with non-bilious vomiting?

Gastroesophageal reflux (GERD) Duodenal atresia Overfeeding Pyloric atresia

21. Visible gastric peristaltic waves moving from left to right across the upper abdomen are a clinical sign of:

Hepatomegaly Gastric outlet obstruction Paralytic ileus Normal infant physiology

22. An infant with HPS presents with severe dehydration and a serum bicarbonate of 35 mEq/L. What is the immediate management priority?

Administer sodium bicarbonate to correct pH Proceed to emergency surgery immediately Delay surgery until fluid and electrolyte abnormalities are corrected Initiate oral rehydration solution (ORS)

23. Which of the following is a recognized, but rarely used, medical treatment for HPS?

Proton pump inhibitors Atropine sulfate Octreotide Prostaglandin inhibitors

24. Jaundice can sometimes be associated with HPS. This is typically due to:

Biliary atresia Hemolysis from electrolyte imbalance Reduced hepatic glucuronyl transferase activity due to starvation Direct compression of the common bile duct

25. What is the long-term prognosis for an infant following a successful Ramstedt pyloromyotomy?

Increased risk of peptic ulcer disease in adulthood Lifelong need for a modified diet Excellent, with no significant long-term gastrointestinal sequelae Higher incidence of developing gastric cancer

Hypertrophic Pyloric Stenosis MCQ Quiz | Pediatric Surgical

Quiz Results