12. What would the acid–base state of a baby with congenital hypertrophic pyloric stenosis be like?
Correct answer: He or she would have a hypochloraemic metabolic alkalosis.
11. How would you treat congenital hypertrophic pyloric stenosis?
Correct answer: This is anomalous in that the more seriously ill the child, the less urgent the operation. With prolonged vomiting the infant becomes dehydrated with a hypochloraemic metabolic alkalosis. In such cases a day or two must be spent…
10. Why is a barium meal used to investigate congenital hypertrophic pyloric stenosis?
Correct answer: This reveals the pyloric obstruction with characteristic shouldering of the pyloric antrum due to the impression made on it by the hypertrophied pyloric muscle. However, this investigation is rarely called for.
9. Why is abdominal X-ray used to investigate congenital hypertrophic pyloric stenosis?
Correct answer: This reveals a dilated stomach with minimal gas in the bowel, in contrast to dilated coils of bowel in intestinal obstruction.
8. Why is ultrasound used to investigate congenital hypertrophic pyloric stenosis?
Correct answer: Ultrasound scan demonstrates the thickened pylorus and large stomach.
7. What special investigations would you use to investigate congenital hypertrophic pyloric stenosis?
Correct answer: (1) Ultrasound. (2) Abdominal X-ray. (3) Barium meal.
6. What are the differential diagnoses for congenital hypertrophic pyloric stenosis?
Correct answer: (1) Intracranial birth injury. (2) Neonatal intestinal obstruction: from duodenal atresia, volvulus neonatorum or intestinal atresia, the symptoms commence within 1–2 days of birth and the vomit contains bile. (3) Enteritis: diarrhoea accompanies this. (4) Overfeeding: here, there…
5. How does an infant with congenital hypertrophic pyloric stenosis present? What are the clinical features of this condition?
Correct answer: The presenting symptom is projectile vomiting. The vomit does not contain bile and the child takes food avidly immediately after vomiting, i.e. he or she is always hungry. There is a failure to gain weight and, as a…
4. After what age is it extremely uncommon for an infant to develop congenital hypertrophic pyloric stenosis?
Correct answer: After 12 weeks of age it is extremely uncommon.
3. What percentage of cases of congenital hypertrophic pyloric stenosis occur in the first born?
Correct answer: Fifty per cent of cases occur in the first born and the condition often occurs in siblings.
