171.A 55-year-old man with a history of alcoholism and osteoarthritis
developed left knee pain several days after a fall from standing height. The
patient was brought to the ED by ambulance after being found on a park
bench stating he was unable to walk because of the pain. On physical
examination, his left knee is warm, diffusely tender, and swollen with a large
effusion. He has pain on passive range of motion. His BP is 150/85 mm Hg,
HR is 105 beats per minute, temperature is 102.7°F, RR is 16 breaths per
minute, and fingerstick glucose is 89 mg/dL. Which of the following is the
most appropriate diagnostic test?
a. Knee radiographs
b. Magnetic resonance imaging (MRI)
c. Erythrocyte sedimentation rate (ESR) and C-reactive protein
d. Arthrocentesis
e. Bone scan
172.A 35-year-old woman with systemic lupus erythematosus (SLE) is
brought to the ED by her brother after he found her febrile and confused.
Physical examination reveals fever, tachycardia, a waxing and waning men-
tal status, petechiae over her oral mucosa, pallor, and mildly heme-positive
stool. Her urinalysis is positive for blood, red cell casts, and proteinuria.
Laboratory results reveal a blood urea nitrogen (BUN) of 40 mg/dL, and a
creatinine of 2 mg/dL. Her bilirubin is elevated (unconjugated > conju-
gated) and her international normalized ratio (INR) is 0.98. Her complete
blood count reveals WBC 12,000/μL, hematocrit 29%, and platelet count
17,000/μL with schistocytes on the peripheral smear. Which of the follow-
ing is the most appropriate next step in management?
a. Admit to the intensive care unit (ICU) for plasmapheresis and close monitoring
for acute bleeds.
b. Admit to the ICU for platelet transfusion and monitoring for acute bleeds.
c. Begin corticosteroids, transfuse platelets, and call surgery for immediate
splenectomy.
d. Admit to the ICU for dialysis and close monitoring for acute bleeds.
e. Perform a noncontrast head computed tomography (CT), followed by a lumbar
puncture (LP) for analysis of cerebrospinal fluid.
180 Emergency Medicine