Spontaneous Pneumothorax (Goljan vs USMLE World)

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kdburton

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I had a USMLE World question the other day where they basically described a guy with a spontaneous pneumothorax (there were no precipitating events such as a stab wound, etc). Then the question was about physical findings and the correct answer was tracheal deviation to the contralateral side. I didn't pick that and I can't remember what the other options are off the top of my head. Goljan says that with spontaneous pneumothorax (i.e. rupture of subpleural bleb) the trachea deviates to the ipsilateral side and that in tension pneumothorax the trachea deviates to the contralateral side. Did I miss something in the history? If not, who is correct here?

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I had a USMLE World question the other day where they basically described a guy with a spontaneous pneumothorax (there were no precipitating events such as a stab wound, etc). Then the question was about physical findings and the correct answer was tracheal deviation to the contralateral side. I didn't pick that and I can't remember what the other options are off the top of my head. Goljan says that with spontaneous pneumothorax (i.e. rupture of subpleural bleb) the trachea deviates to the ipsilateral side and that in tension pneumothorax the trachea deviates to the contralateral side. Did I miss something in the history? If not, who is correct here?

I believe Goljan is correct here. Was it the usual history of a tall, thin, adolescent male? If so, that definitely sounds like spontaneous pnemothorax and I believe in that case the diaphragm is elevated and the trachea deviates to the ipsilateral side.

What was the % correct?
 
I believe Goljan is correct here. Was it the usual history of a tall, thin, adolescent male? If so, that definitely sounds like spontaneous pnemothorax and I believe in that case the diaphragm is elevated and the trachea deviates to the ipsilateral side.

What was the % correct?

I'll have to go back and take a look because I can't remember the rest of the Hx and I don't even know if I looked at the % who got it correct. I'm just studying respiratory path right now and I remembered Goljan's explanation from a while back when i was lisetning to him at the gym and got confused. I'll update this thread a little later when I run through some of the questions I got wrong
 
This is something that always concerns me, particularly with some of the info from Goljan. It's always, "the conventional wisdom says X, but actually if you really look at the literature or note new epidemiological trends, it's actually Y". Sure, that's great to know the "truth", but will that necessarily be reflected on the actual boards? You would hope that they would have questions based on the most up-to-date info, but what if they don't? What if they are retaining questions based on "conventional wisdom" and don't necessarily see a reason to remove them because they are performing well (i.e. a reasonable proportion of people are answering the question "right" based on outdated info)? Those who know MORE about the topic, beyond what is traditionally considered correct, would then be at a disadvantage. And it's not like we get to review the questions afterwards to point out these discrepancies.

Of course, that's probably just me being paranoid. I'm sure they have some sort of review process in place.
 
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FA says in a tension pneumothorax, trachea deviates to the contralateral side, I assume it's the same for a spontaneous pneumothorax?
 
FA says in a tension pneumothorax, trachea deviates to the contralateral side, I assume it's the same for a spontaneous pneumothorax?

What determines if it deviates to the contralateral side is if the pneumothorax is under tension. I believe most spontaneous pneumos (rupture of subpleural bleb) are not under tension, and therefore, the trachea deviates to the ipsilateral side.
 
Up-to-date only describes tension pneumos as having a contralateral deviation, not in the other pneumothorax types. It agrees with Goljan.
 
FA says in a tension pneumothorax, trachea deviates to the contralateral side, I assume it's the same for a spontaneous pneumothorax?

from goljan

in spontaneous pneumothorax there is a rupture of the pleura > pressure equilibrates between atmosphere and lung > the trachea deviates to the ipsilateral side

in tension pneumothorax there is a tear of the pleura forming a 1 way valve > pressure builds up in the intrapleural space and exceeds 1 atm > the trachea deviates to the contralateral side. this can cause compression of the other lung and lead to respiratory failure.

from uptodate

you can also have a unilateral open pneumothorax. During inspiration, ambient air enters the injured hemithorax, competing with intratracheal air and forming a "sucking wound." The mediastinum shifts to the normal side. In expiration, the mediastinum swings to the injured side and expiratory air from the normal lung, so-called pendulum air, enters the collapsed lung. Respiratory failure can result from this mediastinal "flutter."
 
in tension pneumothorax there is a tear of the pleura forming a 1 way valve > pressure builds up in the intrapleural space and exceeds 1 atm > the trachea deviates to the contralateral side. this can cause compression of the other lung and lead to respiratory failure.

3 Kings, anyone ? :)
 
Haha Goljan actually describes that exact part of the movie when he's explaining tension pneumothorax :)

I saw that movie because my undergrad physio teacher mentioned it ....then he mentioned "Memento" when we were talking brains, then some made for TV movie when talking blood groups ....No wonder I got a B in his class ;)
 
In this same lecture i think Goljan also disagrees w/ uworld on the epithelial lining of true vs. false vocal cords...any consensus on that?
 
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In this same lecture i think Goljan also disagrees w/ uworld on the epithelial lining of true vs. false vocal cords...any consensus on that?

This is going off of what I learned in lecture (which was a while back), but I believe that you're right - he got them flip-flopped around.
 
quoted NBME question deleted - lordjeebus

Actually I think this is the question I was talking about. I couldn't remember whether it was a UW question or if it was on an NBME (I also took NBME #3, so I assume thats what I meant when I posed this question haha). I picked rupture of the subpleural bleb even though its inconsistent with the direction of the mediastinal shift according to what I've learned, because none of the other answer choices were better from what I remember
 
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The vignette clearly describes a spontaneous pneumothorax. Going off what I've learned from Goljan, a spontaneous pneumothorax has tracheal deviation to the ipsilateral side. Yet the correct answer implies that the tracheal deviation is contralateral. In First Aid, p. 466 2008 version they do not even subdivide pneumothorax into tension and spontaneous. They just list that all pneumothoraces have contralateral deviation. Goljan made an update to his textbook, p. 326 so that it says with a spontaneous pneumothorax the tracheal deviation is ipsilateral if the majority of the lung is collapsed. From that, it implies that if the majority of the lung isn't collapsed, the tracheal deviation is contralateral.

So I'm thinking this is one of the instances where we should forget about what Goljan says, and assume the boards just wants us to believe that all penumothoraces produce contralateral tracheal deviation. I have no doubt that Goljan is correct as to the level of lung collapse affecting which way the trachea deviates, but from what I've seen on the NBME exam and in first aid, the boards doesn't really get that techincal.

Thoughts?
 
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This also came up on NBME 4, block 3 question #32.

The vignette clearly describes a spontaneous pneumothorax. Going off what I've learned from Goljan, a spontaneous pneumothorax has tracheal deviation to the ipsilateral side. Yet the correct answer implies that the tracheal deviation is contralateral. In First Aid, p. 466 2008 version they do not even subdivide pneumothorax into tension and spontaneous. They just list that all pneumothoraces have contralateral deviation. Goljan made an update to his textbook, p. 326 so that it says with a spontaneous pneumothorax the tracheal deviation is ipsilateral if the majority of the lung is collapsed. From that, it implies that if the majority of the lung isn't collapsed, the tracheal deviation is contralateral.

So I'm thinking this is one of the instances where we should forget about what Goljan says, and assume the boards just wants us to believe that all penumothoraces produce contralateral tracheal deviation. I have no doubt that Goljan is correct as to the level of lung collapse affecting which way the trachea deviates, but from what I've seen on the NBME exam and in first aid, the boards doesn't really get that techincal.

Thoughts?

First of all the NBME questions are not in the same order/blocks for each administration - each person has a different question order. Second - I think its a stretch to say that Goljan's book is implying that if the majority of the lung isn't collapsed then the tracheal deviation is contralateral. That means that the trachea starts out deviating to the contralateral side and then as more lung collapses it deviates to the ipsilateral side (which would mean that the diaphragm findings must switch too) - this completely negates his description of why the trachea deviates to the ipsilateral side on sponaneous pneumothorax in the first place. Its more likely that he means that the trachea doesn't deviate until a majority of the lung is collapsed in which case it deviates to the ipsilateral side. But if three of us agree that the vignette describes a spontaneous pneumothorax and NBME looking for 'tracheal deviation to the contralateral side' then I'll probably just answer it they want me to; unless there is another answer that works the other way (i.e. if another answer choice was "diaphragm elevation on ipsilateral side" then I may pick that)
 
First of all the NBME questions are not in the same order/blocks for each administration - each person has a different question order. Second - I think its a stretch to say that Goljan's book is implying that if the majority of the lung isn't collapsed then the tracheal deviation is contralateral. That means that the trachea starts out deviating to the contralateral side and then as more lung collapses it deviates to the ipsilateral side (which would mean that the diaphragm findings must switch too) - this completely negates his description of why the trachea deviates to the ipsilateral side on sponaneous pneumothorax in the first place. Its more likely that he means that the trachea doesn't deviate until a majority of the lung is collapsed in which case it deviates to the ipsilateral side. But if three of us agree that the vignette describes a spontaneous pneumothorax and NBME looking for 'tracheal deviation to the contralateral side' then I'll probably just answer it they want me to; unless there is another answer that works the other way (i.e. if another answer choice was "diaphragm elevation on ipsilateral side" then I may pick that)

"I will play their game." I know what they want now, so there's no more point in wasting time on this. Thanks for your input.
 
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"I will play their game." I know what they want now, so there's no more point in wasting time on this. Thanks for your input.
I dont think "they" are playing any game....There is just a right answer and a wrong answer. If you pick the right one, you get the credit for a right answer. Just know the material.:sleep:
 
It doesn't have anything to do with "how much" of the lung is collapsed. In a spontaneous or simple pneumothorax, the intrapleural pressure should be less than or equal to atmospheric pressure, so eventually you could have the unaffected side going toward the affected side. In a tension pneumothorax, air is being trapped in the thorax and so intrapleural pressure is higher than atmospheric, which would lead to inflating the affected side (not the lung!) and pushing the unaffected side further away.

At least that's my understanding.

I've also heard that tracheal shift is rarely observed in real life with pneumothoraces.

Anyway, I doubt there is going to be a question where they ask to which side the trachea will shift. In the NBME 3 question (which shouldn't be discussed here BTW) you just had to match the symptoms with the pathophysiology and I think you could have gotten it right without all this discussion.
 
Per the NBME:

"The materials presented on the self-assessments are owned and copyrighted by the NBME. Participants may not transfer or reproduce self-assessment materials in any way without permission from the NBME. Any unauthorized transfer or reproduction of these materials, by any means, including but not limited to, storage in a retrieval system, transmission, printing, memorization, or distribution is strictly prohibited.If the NBME believes that any participant has engaged in or is engaging in the foregoing behavior, the NBME reserves the right to take any and all further action necessary to protect the integrity of the examination, including notifying the participant's medical school or residency program of the suspected unauthorized disclosure of copyrighted materials. Any actions taken by a medical school or residency program on the basis of such information are completely the responsibility of the medical school or residency program."

Hence I have deleted posts in violation of these terms - trust me when I say you don't want to mess with the NBME on this kind of thing.
 
Per the NBME:

"The materials presented on the self-assessments are owned and copyrighted by the NBME. Participants may not transfer or reproduce self-assessment materials in any way without permission from the NBME. Any unauthorized transfer or reproduction of these materials, by any means, including but not limited to, storage in a retrieval system, transmission, printing, memorization, or distribution is strictly prohibited.If the NBME believes that any participant has engaged in or is engaging in the foregoing behavior, the NBME reserves the right to take any and all further action necessary to protect the integrity of the examination, including notifying the participant's medical school or residency program of the suspected unauthorized disclosure of copyrighted materials. Any actions taken by a medical school or residency program on the basis of such information are completely the responsibility of the medical school or residency program."

Hence I have deleted posts in violation of these terms - trust me when I say you don't want to mess with the NBME on this kind of thing.

I think I might have transferred the knowledge to my brain. :rolleyes:
 
Just FYI: I actually got pimped on this question by my resident who said there is tracheal deviation only with tension pneumos. My fellow medical students also agreed with her (I thought, is GOljan wrong?) So I emailed a school radiologist, who basically said you don't usually get tracheal deviation w/ spontaneous pneumothorax.

So i don't know, what the correct answer was, honestly I didn't get any questions about spontaneous vs tension on my step I; even so I don't know what the right answer is, but an internet search, and perhaps if you guys email some of your radiologists will likely reveal that spontaneous pneumothorax rarely results in tracheal deviation at all.
 
in real life, i've never seen nor really heard of simple pneumo's causing tracheal deviation., but i've never seen one greater than 50%. In the case of a tension pneumo, the EM and trauma surg attendings teach that tracheal deviation is the last sign to appear. Hypotension occurs earlier and is the more common point at which it is is diagnosed and corrected.

If a spontaneous pneumothorax causes contralateral deviation, then that spontaneous pneumo is a tension pneumo, which is not really common.
 

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