Master the board step 3

Master the Boards: USMLE Step 3
Vasomotor Shock
Vasomotor shock is the cause of hypotension and tachycardia in patients who
are warm and flushed (rather than pale and cold). Look for a history of medication
use (e.g., penicillin that may have triggered a penicillin allergy), spinal
anesthesia, or exposure to allergen (e.g., bee sting).
Basic Science Correlate
On exposure to an foreign substance, IgE binds to the antigen, forming
an antigen-antibody complex. This complex activates the high-affinity
receptor for the Fc region of immunoglobulin E (FcεRI), leading to mast
cell and basophil degranulation and the release of inflammatory mediators
such as histamine. These mediators cause vasodilation, bronchoconstriction,
tachycardia, and swelling.
The first step in management is to administer vasoconstrictors and fluids.
All impaled objects are
to be removed in the OR
under a controlled setting.
Trauma to Localized Sites
All penetrating wounds with damage to internal organs will need to go to the
OR. If the case describes an object embedded in the patient, never remove it in
the ER or at the scene of the accident.
Head Trauma
Management Steps for the Exam
A man was hit over the head with a baseball bat during a mugging. He has a scalp
laceration and a linear skull fracture on CT scan. He denies loss of consciousness.
There are no neurological signs on exam. Is surgery indicated?
Answer: No surgical intervention is needed for an asymptomatic head injury with a
closed skull fracture (no overlying wound) alone. The next step in management is to
clean any lacerations.
A woman was hit over the head with a baseball bat during a mugging. She has a scalp
laceration, and a comminuted, depressed fracture is seen on CT scan. She denies
loss of consciousness. There are no neurological signs on exam. Is surgery indicated?
Answer: Surgery (repair or craniotomy) is always done for comminuted or depressed
skull fracture, even if the patient is asymptomatic. Send the patient to the OR.
312