02-10-2016, 02:10 PM
NBME CK
A 58 y/o man with a 20-year history of alcoholism is admitted to the hospital for treatment of alcoholic hepatitis. He appears disheveled and malnourished. He is 198 cm (6 ft 6 in) tall and weighs 70 kg (155 lb). BMI is 18 kg/m2. Examination shows jaundice and temporal wasting. Scattered rhonchi are heard throughout all lung fields. Cardiac examination shows no abnormalities. Bowel sounds are normal. The liver span is 16 cm. Sensation to pinprick and light touch is decreased over the feet. Deep tendon reflexes are decreased at the ankles. Laboratory studies show
Hematocrit ---------- 33%
Platelet count ------- 145,000/mm3
Serum
Na+ ----------------- 131 mEq/L
Cl- ------------------- 92 mEg/L
K+ ------------------- 3.1 mEq/L
HC03 ---------------- 26 mEg/L
Mg2+ ---------------- 0.8 mEg/L
Ca 2+ --------------- 5.8 mg/dL
BUN ------------------ 6 mg/dL
Cr -------------------- 0.8 mg/dL
Test of the stool for occult blood is positive. Which of the following is the most likely mechanism of this patient's hypocalcemia?
A) Chronic metabolic acidosis
B) Hypomagnesemia
C) Impaired hydroxylation of vitamin D
D) Primary hyperparathyroidism
E) Renal resistance to parathyroid hormone
A 58 y/o man with a 20-year history of alcoholism is admitted to the hospital for treatment of alcoholic hepatitis. He appears disheveled and malnourished. He is 198 cm (6 ft 6 in) tall and weighs 70 kg (155 lb). BMI is 18 kg/m2. Examination shows jaundice and temporal wasting. Scattered rhonchi are heard throughout all lung fields. Cardiac examination shows no abnormalities. Bowel sounds are normal. The liver span is 16 cm. Sensation to pinprick and light touch is decreased over the feet. Deep tendon reflexes are decreased at the ankles. Laboratory studies show
Hematocrit ---------- 33%
Platelet count ------- 145,000/mm3
Serum
Na+ ----------------- 131 mEq/L
Cl- ------------------- 92 mEg/L
K+ ------------------- 3.1 mEq/L
HC03 ---------------- 26 mEg/L
Mg2+ ---------------- 0.8 mEg/L
Ca 2+ --------------- 5.8 mg/dL
BUN ------------------ 6 mg/dL
Cr -------------------- 0.8 mg/dL
Test of the stool for occult blood is positive. Which of the following is the most likely mechanism of this patient's hypocalcemia?
A) Chronic metabolic acidosis
B) Hypomagnesemia
C) Impaired hydroxylation of vitamin D
D) Primary hyperparathyroidism
E) Renal resistance to parathyroid hormone