pneumothorax

Discussion in 'Step I' started by obiwan, Jun 17, 2008.

  1. obiwan

    obiwan Junior Member

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    does spontaneous pneumothorax always cause tracheal deviation to the ipsilateral side and tension pneumo. always cause deviation to contralateral side?
     
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  3. It'sElectric

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    I have no idea if they always do, but I'm pretty sure that's the line of thinking you should have. At least that's exactly how I'll approach any question I see on Step I. Goljan does a great job of explaining this on his audio.
     
  4. RxnMan

    RxnMan Who, me? A doctor?
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    What's that guy's name? Oh yes, George Clooney and that movie, "Three Kings" :laugh:

    Also remember that the wounds are different - tension will be a sucking chest wound -> pierced lung, diaghragm will be pushed down. A spontaneous one will have no external injury, diaphragm pushed up by vicera, MCC a pleural bleb (aka small congenital weakness in the lung), MC in tall skinny guys. Also: 9/10 times it's 'cause the kid was smoking pot.
     
  5. GynGuy1983

    GynGuy1983 C&A Psychiatry Fellow

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    Are you being factitious?

    Also, the reference to the tall skinny guys can also allude to Marfan's syndrome, they also have a predisposition to spontaneous pneumothorax because of the abnormal fibrillin (i.e. abnormal elastic fibers, recoil forces, . . .).
     
    #4 GynGuy1983, Jun 17, 2008
    Last edited: Jun 18, 2008
  6. RxnMan

    RxnMan Who, me? A doctor?
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    Dead serious. Came from a private ICU doc I know who practices in suburbia. I've also been told it's on the EM board exams. Makes it easy to remember. If you don't believe me, think about this - what other activity is going to cause a greater pressure drop across the lung?

    Yes, the "tall & skinny" description can also be applied to Marfans, but you're going to get a host of other features in the question (heart murmur, PHx of dislocated lens, pointy fingers, etc.) that'll point you towards Marfans.

    All stems give you a CC which leads to a DDx. The rest of the question gives you HX + tests (both of which either eliminate some items on that DDx or make others more likely).
     
  7. GynGuy1983

    GynGuy1983 C&A Psychiatry Fellow

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    Good point. I will be sure to remember that when I start my residency.
     
  8. TerpMD

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    According to emedicine, spontaneous pneumo can convert to tension. So I would make sure to look at how sick the patient is in addition to the "tall lanky boy" factor. This concept is tested on NBME 4 though I will not give the details since we aren't supposed to post NBME qs :)
     
  9. obiwan

    obiwan Junior Member

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    Yeah, my question was referring to that question since none of the choices made sense.
     
  10. lord_jeebus

    lord_jeebus 和魂洋才
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    Someone correct me if I'm wrong but I would not expect to see tracheal deviation in a primary spontaneous pneumothorax, unless it becomes a tension pneumothorax.
     
  11. MSKalltheway

    MSKalltheway I got the magic stick

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    Ditto. TerpMD and I just had a convo about this, and the question only makes sense after you consider that spontaneous --> tension. I studied the hell out of the lung PE findings too, that really p*ssed me off :mad:
     
  12. RxnMan

    RxnMan Who, me? A doctor?
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    Huh. I was taught they were two separate entities, but I kinda wondered how the collapsed lung in spontaneous never leaked air into the pleural space, i.e. didn't convert.

    Makes sense, will watch for it come the real thing. Thanks. :thumbup:

    Sorry I didn't catch your meaning. I was more caught up on quoting Goljan. :laugh:

    I thought the tracheal deviation, in either case, came from mass effect/pressure differences. In tension, trapped air -> inc. pressure -> pushes trachea away.

    In spontaneous (if it hasn't converted!) the lung isn't inflated, there's less pressure on that side, the viscera pushes up and the trachea may deviate towards that side. Not as much as tension, but some.

    This comes from a preclinical student who's never seen either! :laugh:
     
    #11 RxnMan, Jun 18, 2008
    Last edited: Jun 18, 2008

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