I think the idea here is that if you take someone off a PPI, if there's no neoplasm or any problem with gastrin production then you should see it go down from baseline due to more negative feedback of gastric acidity. If not, you probably have a neoplasm that's just making tons of gastrin, such as in the case of Zollinger-Ellison syndrome.
The use of any agent that inhibits gastric secretion of acid (H2-receptor antagonists or PPIs) will result in a rise in serum gastrin as the feedback inhibition of gastrin release is diminished.
If you want to rule out Zollinger-Ellison syndrome you need to stop the PPIs first, then measure Gastrin to make that your intial measure of elevated Gastrin was not due to your drug rather than the patients disease.
Hi everyone I just came here to say that this was the last question on my NBME and I put a note on it saying "Zollinger-Ellison BOIIII" and then I selected plasma VIP as my answer choice because I'm an idiot.
We live and learn my friends.
When ZES is suspected, the initial test recommended is a fasting serum gastrin (FSG) determination in the absence of antisecretory therapy (Sensitivity- 98โ100% in ZES patients various series. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5757869/
I thought this was just referencing zollinger ellison, which would have elevated gastrin
To me: this seemed more straightforward. You'd want to follow up and check Gastrin levels on a patient who previously had 4x normal.
in my opinion , this was one of the most difficult questions . why ? the answer is soooooo simple that you might be mislead thinking "naaaahh cant be that easy ...nbme .. you playin witme hun?? imma choose the most complex answer and shove it in your face"
student chooses VIP, and afterwards locks him self up with his new record level low self esteem
submitted by โpaperbackwriter(161)
SO suspiciously obvious... NBME has given me trust issues