Vomiting every feed, but still hungry?
A 5-week-old boy has vomited forcefully after every feed for 4 days. The vomit is milky, not green, and he feeds hungrily straight afterwards. His gas shows a raised pH and bicarbonate, with low chloride.
What's the diagnosis, and what must happen before theatre?
Pick the diagnosis
Need a clue?
The vomit isn't green, so the blockage is above where bile enters. And the baby is still hungry, because the milk never gets past the stomach.
Show the answer
Pyloric stenosis
- What's going on
- The muscle of the pylorus (the stomach outlet) thickens, so milk struggles to get through to the duodenum.
- Spot it
- Projectile, non-bilious vomiting after feeds in a hungry baby, usually 2 to 8 weeks old. About 4 times more common in boys. An “olive” mass may be felt during a test feed.
- The gas
- Vomiting stomach acid causes a hypochloraemic metabolic alkalosis, often with low potassium as the kidneys hold on to fluid. Babies caught early may have normal bloods.
- Test
- Ultrasound of the pylorus.
- Treatment
- Correct fluids and electrolytes first, and only operate once the bloods are normal. Then a pyloromyotomy (Ramstedt): the thickened muscle is split, leaving the lining intact. Open or keyhole.
- Why it matters
- It is a medical emergency before it is a surgical one: fix the fluids and salts first.
Go further
Tap a question to check your answer.
Why isn't the vomit green?
The blockage is above where bile enters the gut.
Why is the baby still hungry?
The milk comes straight back up, so they haven't really fed. They are otherwise well, so they still want more.
What does the blood gas tell you?
A hypochloraemic metabolic alkalosis, from losing stomach acid. Potassium is often low too.
Why not go straight to theatre?
Fluids and electrolytes must be corrected first. An uncorrected alkalosis makes the baby breathe less, so they are more likely to stop breathing (apnoea) after the anaesthetic.
Harder: what's the operation?
Pyloromyotomy: split the thickened muscle, leaving the lining intact.
Source: Patient.info Professional
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