nbme 7 qs.. - mahr90

[ArchivalUser]

A previously healthy 57 year old man comes to the emergency department because of mild left flank pain and intermittent blood in his urine for 3 days. He takes no medications. He appears to be in mild distress. His temperature is 37.2C (99F), pulse is 88/min, respirations are 12/min and blood pressure is 146/94 mm Hg. Examination shows mild left costovertebral angle tenderness. His serum calcium concentration is 10.9 mg/dL, serum phosphorous concentration is 2.3 mg/dL, a serum intact parathyroid hormone concentration is 1020 pg/ml (N=10-65). A CT scan of the abdomen shows renal calculi bilaterally. Which of the following is the most likely cuase of the calculi?

A) Decreased urinary excretion of citrate
B) Decrease urinary excretion of uric acid
C) Increased gastrointestinal absorption of oxalate
D) Increased urinary excretion of calcium
E) Increased urine pH

plz explain..

[ArchivalUser]

dd
pt has hyperPTH with increase calcium and low phosphorius ...= hypercalcinuria

i think so altough increase urine ph = calcium po4 stones but they are in RTA-1

so may be DD

[ArchivalUser]

d is right got it right online

[ArchivalUser]

i marked it D but then changed to E
I don't get if PTH is sooo high then shouldn't Ca be also more high? 10.9 is upper limit of normal.. :S
plz explain more..

[ArchivalUser]

ca is high and also see phosphorus low = hyperparathyroid which is more common ..i guess no better logic i have ;-(

they are so close option you are bound to fall in trap

[ArchivalUser]

it was more of gut answering js reasoned like medplus n chose d and moved on maybe someone can giv us a more in depth view

mahr90 goodluck

[ArchivalUser]

@manga true, i changed 3 qs from right to wrong cz of overthinking GL to u too & thanks (:

[ArchivalUser]

D)