NBME 15- Block 3 (Duplicate 2)

A 50-year-old woman is brought to the emergency department because of a 6-day history of confusion, increased thirst, progressive fatigue, and constipation. She also has a 2-month history of moderate low back pain. She has hypertension treated with lisinopril. She is somnolent but easily arousable. She is oriented to person and place but not to time. Temperature is 37.2°C (99.0°F), pulse is 112/min, respirations are 18/min, and blood pressure is 100/60 mm Hg. On examination, the conjunctivae are pale. There is decreased axillary sweat. Cardiopulmonary examination shows no other abnormalities. Results of laboratory studies are shown:

Intravenous administration of 0.9% saline is begun. Eight hours later, examination findings and laboratory study results are unchanged. In addition to continuing intravenous administration of fluids and beginning furosemide therapy, which of the following is the most appropriate next step in management?

A 7-year-old boy is brought to the office by his mother because of a 1-week history of hair loss and a 1-month history of an enlarging, itchy lesion on his scalp. He has no history of serious illness. Vaccinations are up-to-date. Physical examination shows the findings in the photograph. Microscopic examination of a scraping of the lesion treated with KOH shows branching hyphae. Which of the following is the most appropriate initial pharmacotherapy for this patient?

A 4-year-old boy is brought to the office by his parents because of a 2-year history of sunburns and redness of both eyes. His parents say his skin becomes red and irritated after 15 minutes of sun exposure. Whenever he is outside, his eyes become red. Growth and development otherwise have been appropriate for age. Vaccinations are up-to-date. He is at the 50th percentile for height, weight, and BMI. His temperature is 37.0°C (98.6°F), pulse is 106/min, and respirations are 24/min. A photograph of the skin is shown. Ocular examination discloses injection of the conjunctival vessels without discharge bilaterally. Which of the following is most likely to develop in this patient during the next 10 years?

A 23-year-old woman comes to the emergency department because of a 3-month history of increasingly painful circumferential headaches that are most severe when she lies down. During this time, she also has had intermittent episodes of “grayed out” vision with constriction of her visual fields. The episodes last 5 seconds and resolve spontaneously. The patient was treated for Chlamydia trachomatis infection 2 years ago. She has no other history of serious illness and takes no medications. Her diet consists mainly of “junk food.” She appears anxious. She is 157 cm (5 ft 2 in) tall and weighs 124 kg (273 lb); BMI is 50 kg/m2. Her blood pressure is 165/82 mm Hg; other vital signs are within normal limits. Findings on funduscopic examination of the right eye are shown; similar findings are noted in the left eye. The remainder of the examination shows no abnormalities. Lumbar puncture is performed, and opening pressure is 39 cm H2O. Results of cerebrospinal fluid analysis are within the reference ranges. MRI of the brain and MR venography show no abnormalities. Which of the following is most likely to have prevented this patient’s current symptoms?

A clinician would like to increase the accuracy of diagnosing streptococcal pharyngitis among his pediatric patients in order to begin treatment sooner. He considers implementing a new diagnostic test for streptococcal pharyngitis and reviews the receiver operator characteristic (ROC) curve shown. Which of the following is the most likely clinical impact of using cut point C instead of cut point B as a positive test?