q5 - honey91

[ArchivalUser]

A 62-year-old 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 mEq/L

K+ 3.1 mEq/L

HCO3“ 26 mEq/L

Mg2+ 0.8 mEq/L

Ca2+ 5.8 mg/dL

Urea nitrogen (BUN) 6 mg/dL

Creatinine 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

[ArchivalUser]

I'd go for bbbbbbb hypoMg causes decrease of PTH which in turn decrease Ca

[ArchivalUser]

well, as far as I remember, the hypocalcemia in alcoholics is due to hypomagnesemia. So I'll go with BB

[ArchivalUser]

Normla value of Mg is 1.6-2.6 mg/dl ,so his Mg is 0.8 ---Hypomagnesimia.He is a chronic alcoholic with liver disease that can cause the Mg to decrease ,and he is malnourish , which can be cause for decrease Mg.I know that hypocalcemia frequentelly accompanies hypomagnesemia.
A

[ArchivalUser]

C -usually hydroxilation happend in kidney rigth??
D -we have increase Ca
E is usally some genetic disorder...
A - in acidosis - no relathionship with Ca ,but relative increase in K I guess...
BBB

[ArchivalUser]

C- first hydroxylation step takes place in the liver when
Vit D3 is converted to calcidiol( 25-hydroxy cholecalciferol) by the liver microsomal enzyme,25-hydroxylation and stored in the liver until it is needed. Here liver failure so, this is affected.
The 2nd step of hydroxylation takes place in the kidney when 25 OH clolecalciferol is converted to 1,25 dihydroxycholecalciferol by 1-alpha hydroxylase in the kidney.

[ArchivalUser]

Now, vit D cause reabsorption of Ca from intestines and kidney and then deposit Ca in the bone…So,vit D has not direct effect on Ca in the blood ,but indirect effect on Ca by depositing it to the bone. I will still go for answer BB

[ArchivalUser]

NBME 3 question for step 2 CK

this deviate ur score expctancy on NBME please stop sending NBME question with our marking them people