Master the board step 3

Nephrology
A patient is brought to the emergency department after a seizure leading to
prolonged immobility on a sidewalk. He has dark urine and myalgias. What is the
most urgent step in the management of this patient?
a. Urinalysis
b. Urine myoglobin level
c. EKG
d. CPK level
e. Phosphate level
f. Creatinine
Answer: C. EKG is the most urgent step in an acute case of rhabdomyolysis. This case
tests your knowledge of how people die with rhabdomyolysis. Severe muscle necrosis
leads to hyperkalemia, which leads to arrhythmia. If this is a CCS case, then all of the
tests should be done simultaneously. A specific diagnosis with urinalysis or urine myoglobin
is not as important as detecting and treating potentially life-threatening conditions,
such as hyperkalemia with peaked T waves. This condition would be treated with
immediate intravenous calcium gluconate, insulin, and glucose.
Crystal-Induced Renal Failure
This condition can result from oxalate crystals or uric acid crystals.
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Oxalate crystals: Look for suicide by antifreeze ingestion (ethylene glycol).
The patient will be intoxicated with metabolic acidosis with an elevated
anion gap.
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Best initial test: Urinalysis showing envelope-shaped oxalate crystals
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Best initial treatment: Ethanol or fomepizole with immediate dialysis
Oxalate crystals
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Uric acid crystals: Look for tumor lysis syndrome, most often after chemotherapy
for lymphoma.
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Treat with hydration, allopurinol, and rasburicase.
Rasburicase breaks down
uric acid.
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