347.A 29-year-old woman presents to the ED complaining of double vision
for 3 days. She states that she has been feeling very tired lately, particularly at
the end of the day, when even her eyelids feel heavy. She feels better in the
morning and after lunch when she is able to rest for an hour. Her BP is
132/75 mm Hg, HR is 70 beats per minute, temperature is 98.4°F, and RR
is 12 breaths per minute. On examination you find ptosis and proximal
muscle weakness. What is the most appropriate diagnostic test to perform?
a. Edrophonium test
b. Serologic testing for antibodies to acetylcholine receptors
c. Head computed tomography (CT) scan
d. Electrolyte panel
e. Lumbar puncture
Questions 348 to 349
348.A 40-year-old woman is brought to the ED by the paramedics com-
plaining of bilateral foot weakness and numbness that started a few hours
ago and is progressively worsening. She denies similar episodes in the past.
On the review of systems, she describes having abdominal cramps with nau-
sea, vomiting, and diarrhea 2 weeks ago that resolved after 2 to 3 days. Her
BP is 124/67 mm Hg, HR is 68 beats per minute, temperature is 98.8°F, and
RR is 12 breaths per minute. On examination, you elicit 2/5 strength,
decreased sensation, and loss of deep tendon reflexes in the lower extremities
below the hips. Which of the following is the most likely diagnosis?
a. Hypokalemic periodic paralysis
b. Guillain-Barré syndrome
c. Peripheral vascular disease
d. Tetanus
e. Brain abscess
349.What life-threatening complication is associated with this disease process
described in the previous question?
a. Permanent paralysis
b. Thrombocytopenia
c. Respiratory failure
d. Need for surgery
e. Kidney failure
374 Emergency Medicine