Pyloric Stenosis

Question 1

What causes pyloric stenosis?

Answer 1

Hypertrophy of pyloric muscle causing gastric outlet obstruction

Question 2

What is the common age of presentation of pyloric stenosis?

What other descriptive features of presenting child are there?

Answer 2

Between 2-7 weeks

More common in boys (4:1), particularly 1st born, may be family Hx, esp. on maternal side.

Question 3

What are the clinical features of pyloric stenosis?

Answer 3

• Vomiting, which increases in frequency and force over time.
• Hunger after vomiting (until dehydration leads to a lack of interest in feeding)
• Hypochloraemic metabolic alkalosis with decreased plasma sodium and potassium (due to vomiting stomach contents)
• Weight loss if presentation delayed

Question 4

What investigations are indicated in pyloric stenosis?

Answer 4

Test feed - baby given milk feed - gastric peristalsis may be seen - wave moving left to right across abdomen. Pyloric mass can be palpated - feels like an olive - palpable in RUQ.

Ultrasound if diagnosis in doubt.