Pulmonary hypoplasia

[MudPhud20XX]

Here is a Kaplan Question:

An infant is born with a poorly developed left lung. This condition was most likely caused by which of the following?

A. Bilateral renal agenesis
B. Congenital diaphragmatic hernia
C. Oligohydramnios
D. Potter sequence
E. Respiratory distress syndrome

The answer is B

1. However, pulmonary hypoplasia can be caused by A (bilateral renal agenesis), correct? Then why isn't A the answer?

2. So amniotic fluid is made by the kidney, that's why bilateral renal agenesis leads to oligohydramnios, correct?

3. Kaplan says "Bilateral renal agenesis causes oligohydramnios, which increases the pressure on the fetal thorax." However, should the pressure drop since there is less amniotic fluid? Can anyone explain this?

Many thanks in advance.

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[Missorleans]

The key is that it's the only the left lung that is poorly developed. Points to something structural impeding on the growth of only one side. Congenital diaphragmatic hernia.

 

[Missorleans]

By "increases pressure on the fetal thorax", they mean pressure from like, the uterus. Fluid isn't going to impinge on formation, it cushions the fetus.

 

[Apoplexy__]

Wow, this question sucks. Don't make 3/5 of the answer choices basically the same idea, come on guys.

 

[MudPhud20XX]

The key is that it's the only the left lung that is poorly developed. Points to something structural impeding on the growth of only one side. Congenital diaphragmatic hernia.

thanks!

 

[NeuroLAX]

Would Step 1 require us to know Bochdalek vs Morgagni and that Bochdalek the is most common and seen in the posterior L side? I had this question on my class midterm a few days ago.

 

[Fatalis]

Wow, this question sucks. Don't make 3/5 of the answer choices basically the same idea, come on guys.

if it wasnt a random obscure/b*tch question.....it simply would not be a kaplan question! lol

 

[Missorleans]

Would Step 1 require us to know Bochdalek vs Morgagni and that Bochdalek the is most common and seen in the posterior L side? I had this question on my class midterm a few days ago.

IIRC, one of them accounts for like 95% of them, so I doubt it. But it's possible. It would be one of those questions that separates 270 from 280

 

[thehundredthone]

Wow, this question sucks. Don't make 3/5 of the answer choices basically the same idea, come on guys.

Actually one could argue that those 3 can be ruled out all at once because they would all cause bilateral hypoplasia.

 

[Apoplexy__]

Actually one could argue that those 3 can be ruled out all at once because they would all cause bilateral hypoplasia.

I know that's what they were going for, but I was able to get it right without knowing that a diaphragmatic hernia caused unilateral hypoplasia simply by knowing 2 things:
-Bilateral renal agenesis --> oligohydramnios --> Potter sequence, so since only one answer choice can be right, these must all 3 be wrong
-ARDS doesn't cause hypoplasia

I was able to get it right by circumventing what they were trying to test. That's all I mean.

 

[Transposony]

I know that's what they were going for, but I was able to get it right without knowing that a diaphragmatic hernia caused unilateral hypoplasia simply by knowing 2 things:
-Bilateral renal agenesis --> oligohydramnios --> Potter sequence, so since only one answer choice can be right, these must all 3 be wrong
-ARDS doesn't cause hypoplasia

I was able to get it right by circumventing what they were trying to test. That's all I mean.

Great example of getting the right answer even if don't know anything about it IF you know about other answer choices.

 

[mcloaf]

Would Step 1 require us to know Bochdalek vs Morgagni and that Bochdalek the is most common and seen in the posterior L side? I had this question on my class midterm a few days ago.

It's in FC whatever that means.

 

[thehundredthone]

I know that's what they were going for, but I was able to get it right without knowing that a diaphragmatic hernia caused unilateral hypoplasia simply by knowing 2 things:
-Bilateral renal agenesis --> oligohydramnios --> Potter sequence, so since only one answer choice can be right, these must all 3 be wrong
-ARDS doesn't cause hypoplasia

I was able to get it right by circumventing what they were trying to test. That's all I mean.

That was going to be the second half of my argument. I decided to leave it out because sometimes people go wrong with that approach.

And I guess your initial point was that you didn't like the fact that they could all be ruled out at once. I did not read your post that way at first.

 

[Ionian]

Wow, this question sucks. Don't make 3/5 of the answer choices basically the same idea, come on guys.

Welcome to Step 1 questions.

Frequently the answer choices are related, that's how to determine if you actually know anything...and you can differentiate similar clinical pictures by actually understanding physical diagnosis -.-

 

[Apoplexy__]

Welcome to Step 1 questions.

Frequently the answer choices are related, that's how to determine if you actually know anything...and you can differentiate similar clinical pictures by actually understanding physical diagnosis -.-

Completely missed my point.

And I guess your initial point was that you didn't like the fact that they could all be ruled out at once. I did not read your post that way at first.

Exactly.

 

[notbobtrustme]

It's in FC whatever that means.

I finished every question in UW and Rx on the pulm section and the most detail the questions went into detail was "foramen of bochladek". If you know that **** can herniate through a hole in the diaphram, you should be able to get there for most questions.