NBME 20 Answers : Block 2 : #20 = A 19-year-old man who is a college student is ...

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NBME 20 Answers

nbme20/Block 2/Question#20

A 19-year-old man who is a college student is ...

Subcutaneous crepitus

+9 upvote downvote
submitted by strugglebus(63),

Bronchophony= pneumonia Expiratory stridor= tracheobronchial obstruction (mass/foreign body) Inspiratory stridor = laryngeal obstruction Succussion splash= test for pyloric stenosis

When there is a fractured rib it will cause a trauma pnemothorax which can cause air to escape and become trapped under the skin leading to crepitus.

charcot_bouchard Actually when a fractured rib puncture lung then it cause sc emphysema. +

+0 upvote downvote
submitted by monoloco(49),

I have regarded crepitus as the rubbing of bone-on-bone. My study partner and I think this is a purely definitional question. Yes, crepitus could also be trapped air. Context, I guess.

medstudent65 Crepitus is used to describe bone-on-bone grinding. Subcutaneous crepitus is very specific sound referencing air finding its way into the skin which you can hear but also feel by rubbing your hand over the affected area. The addition of subcutaneous lets you know we are specifically talking about air in the skin. +1

+0 upvote downvote
submitted by rio19111(3),

Diagnosis: Pneumomediastinum (FA 2019, 659)

+Hamman Sign=Crepitus on cardiac auscultation

Etiology: spontaneous (due to rupture of pulmonary bleb) or 2° (eg, trauma, iatrogenic, Boerhaave syndrome).

-1 upvote downvote
submitted by masonkingcobra(55),

Here is a fantastic picture to understand

https://www.semanticscholar.org/paper/Pneumomediastinum-in-the-neonate.-Cagle/7b235daea2488612a1917009afc849afc3e262e7/figure/4