need help with your account or subscription? click here to email us (or see the contact page)
join telegramNEW! discord
jump to exam page:
search for anything ⋅ score predictor (โ€œpredict me!โ€)

NBME 23 Answers

nbme23/Block 2/Question#35 (reveal difficulty score)
A 42-year-old man with a history of recurrent ...
Magnesium ammonium phosphate ๐Ÿ” / ๐Ÿ“บ / ๐ŸŒณ / ๐Ÿ“–
tags:

 Login (or register) to see more


 +3  upvote downvote
submitted by โˆ—krewfoo99(115)
get full access to all contentpick a username

Image shows Stahorn Calculus

1) Staghorn Calculus in adults - Manesium Ammonium Phosphate 2) Staghorn Calculus in Children - Cystine

get full access to all contentpick a username
cuteaf  The history of recurrent pyelonephritis + fever is also a giveaway that this was due to a bacterial infection. +1
an1  I thought the image looked like stag horn, but the pH is acidic, and MAP is alkaline! whyyy do they do this, literally mixing up incorrect info (unless im wrong, in that case lmk) +
bcher  normal urine pH is 4.5-8. Seems to me that 7.3 is on the higher side. +2



 -2  upvote downvote
submitted by chetzy(0)
get full access to all contentpick a username

increase ph shows its magnesium ammonium phosphate crystals.ph 7.3

get full access to all contentpick a username
bulgaine  The image shows a staghorn calculi which content is usually magnesium ammonium phosphate (can also be cystine but pH would be decreased not increased) and is caused by urease positive bugs that hydrolyze urea to ammonia leading to urine alkalinization (page 586 of FA 2019) +1
nukie404  Patient also has a fever, suggestive of a UTI +1
sigecapps  Why not calcium phosphate, also at high pH? I was between the two but decided on calcium phosphate because the images of staghorn I've seen seem to be more smooth and rounded. I guess should've gone more based on the pyelonephritis symptoms as well caused by the stone harboring bacteria. +1
jaramaiha  The high pH is the best thing to assess in urine which would indicate that it's an infection w/ proteus mirabilis, which is urease(+). FA20 pg 528 +1



Must-See Comments from nbme23

ferrero on Precapillary resistance
yotsubato on 99%
sne on Triglyceride
sajaqua1 on Area labeled โ€˜Dโ€™ (Spinothalamic tract, right)
stinkysulfaeggs on Hypoglycemia
hayayah on Iris
soph on Peak inspiratory pressure (alveolar): ...
seagull on Area labeled โ€˜Cโ€™ (Cranial nerve 8: ...
water on Dietary change
wired-in on 28.8
beeip on Binding of permeable ligand to nuclear ...
thomasalterman on Hypoglycemia
yotsubato on Inhibition of the cytochrome P450-dependent ...
seagull on Decreased sodium bicarbonate reabsorption in ...

search for anything NEW!