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For this category of entities, we're going

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to be discussing two main types

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of iatrogenic disorders in pediatric patients.

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The first is foreign body aspiration.

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It's no secret that young children

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and sometimes even older children

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will put various foreign bodies into their mouths,

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and sometimes they can swallow them,

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but sometimes they aspirate them.

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And when they aspirate a foreign body,

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it can get lodged into an airway

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and a couple of things can potentially happen.

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One is that there can be a ball valve type mechanism leading

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to air trapping or hyperinflation of the distal lung,

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or a, conversely, if there's total obstruction,

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there can be ectasis.

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The difference between these two is that

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with the ball valve mechanism, air can get in

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during inspiration when the airways are more expanded.

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But then during exhalation, when the airways collapse,

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the obstructive foreign body obstructs any air from

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egressing, and so therefore you get the air trapping.

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Whereas without ectasis, no air can get in or out,

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and so you have collapse of the airway.

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So foreign body aspiration can ultimately have opposite

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effects depending on the severity of the obstruction.

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With atelectasis due to aspiration,

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you can have superimposed pneumonia at times.

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And so when we are asked to evaluate

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for potential foreign body aspiration, we have a number

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of choices on imaging In pediatric patients.

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Sometimes we are asked to get inspiratory

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and expiratory radiographs.

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This would be done in older children

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who can follow directions and take a big deep breath in

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or a big deep breath out,

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and we can time the radiographs

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to do it when they follow the directions.

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In younger children, who are the more likely ones

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to put things in their mouths who cannot follow directions,

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we could also consider decubitus views in addition

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to a frontal, supine or upright view.

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Decubitus views are frontal views,

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but with the patient on either side.

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The idea with both of these sets, inspiratory, expiratory,

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or decubitus views, is that if you have air trapping due

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to foreign body aspiration, then when you expect

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to have ectasis, you don't see ectasis more specifically

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during exhalation, you expect a normal amount of ectasis,

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but if you have air trapping during exhalation,

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you'll have areas that do not undergo ectasis

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because of the air trapping.

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Similarly, the thinking with decubitus views is

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normally if you lay on one side,

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that downside is gonna have some ectasis just by gravity.

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And then if you lay on the other side,

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the opposite side will have some ectasis.

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Whereas if you have air trapping with hyper expanded lung

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and you lay on the ipsilateral side, it won't have ectasis.

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On the imaging, you'll see a hyper

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expanded lung when you expect

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To see a PA lung from ectasis.

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And then you can compare these to a standard frontal

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to see if you think there's truly hyper rated lung.

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So that's the idea behind either of those sets of images is

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to look for air trapping when you don't expect air trapping,

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specifically when you expect atelectasis.

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In reality, those images are not that sensitive a lot

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of the time, and

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so more institutions are moving towards low dose

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CT scans looking for foreign bodies.

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And so this is something

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to consider if you're not already aware of.

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CT protocols can now be such

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that the radiation dose is quite low,

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but the imaging findings are much more specific

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for the presence or absence

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of a foreign body lodged in an airway.

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And I will show you some cases

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to illustrate why this can be helpful.

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The other major category of iatrogenic disorders

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that we will discuss is non-accidental trauma.