Double bubble sign

[loveoforganic]

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I know this is pathognomonic for duodenal atresia, but would you also have a chance of seeing it in other congenital obstructions of the GI tract, e.g. annular pancreas?

 

[AndyRSC]

Yep, you could, though I think Step I would most likely give you the plain old, stereotypical duodenal atresia, probably in the context of Down syndrome.

For purposes of step II pediatrics and real life, you could see it with annular pancreas, malrotation, or Ladd's bands. All will have bilious vomiting with first feed.

A bit more here, if you're interested.

 

[loveoforganic]

Gracias!

 

[Siggy]

Don't forget about the olive shaped mass for duodenal atresia.

 

[AndyRSC]

You're thinking of pyloric stenosis. Almost the same region, but very unique presentation. Vomiting here will be around the third week of life, and non-bilious.

Pretty sure I had this on my step I exam, so it may be an extra point for you.

 

[Siggy]

You're thinking of pyloric stenosis. Almost the same region, but very unique presentation. Vomiting here will be around the third week of life, and non-bilious.

Pretty sure I had this on my step I exam, so it may be an extra point for you.

That's what I get for replying to posts while listening to DIT.


🙁

 

[AndyRSC]

You'll get it right on the step, though. The best way to learn things for good is to miss them at some point - whether in a qbank, while being grilled by a preceptor, or on SDN. Stays with ya.

 

[loveoforganic]

In this same vein, is projectile vomiting and hypertrophic pyloric stenosis a comparable situation? Pathognomonic as far as step, but also a possible symptom of the other obstructions? Or is the muscular hypertrophy a critical element to get that force?

 

[Phloston]

Not only is the olive-shaped mass hypertrophic pyloric stenosis, but if they ask about possible Sx, jaundice secondary to conjugated hyperbilirubinaemia can occur due to compression of the common bile duct running through the hepatoduodenal ligament. I had encountered that in a practice question somewhere. They'll try to throw epigastric pain at you, but if jaundice is there, that's the answer.

And I also recall Kaplan QBook, which loves its minutiae, having mentioned that Smith-Lemli-Opitz is a notable genetic disease that presents with pyloric stenosis (as well as high forehead, syndactylyl of the second and third toes and MR).

Pyloric stenosis is always 2-3 weeks post-birth (non-bilious vomiting).
Duodenal atresia is always 2-3 days post-birth (bilious vomiting).

If the patient has constipation and bilious vomiting, even if they don't mention distended abdomen or failure to pass meconium, it's Hirschsprung's, not duodenal atresia.

 

[Phloston]

In this same vein, is projectile vomiting and hypertrophic pyloric stenosis a comparable situation? Pathognomonic as far as step, but also a possible symptom of the other obstructions? Or is the muscular hypertrophy a critical element to get that force?

As far as I'm aware, "projectile vomiting" is pyloric stenosis, so I would assume that it would also be seen with other obstructive pathology.

Notably, I remember having seen in a practice question a vignette of a child with "forced vomiting" and the answer was pyloric stenosis. I was blown away, because that makes it sound as though the child is trying to throw up but barely can. I think they meant forceful vomiting, but I keep a mental note of that regardless.