ite question

[dillpickles]

"An elderly man has an acute dissection of descending thoracic aorta. Which of the following antihypertensives is most likely to extend the dissection?"
a. esmolol
b. nitroglycerin
c. nitroprusside
d. nitroprusside with a beta-blocker
e. trimethaphan

answer = c - i assume this is b/c of reflex tachy/increased contractility? what about nitro?

thanks!

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[Dryacku]

Thats true and also nitroprus is a potent arterial dilator as well...

 

[pgg]

"An elderly man has an acute dissection of descending thoracic aorta. Which of the following antihypertensives is most likely to extend the dissection?"
a. esmolol
b. nitroglycerin
c. nitroprusside
d. nitroprusside with a beta-blocker
e. trimethaphan

answer = c - i assume this is b/c of reflex tachy/increased contractility? what about nitro?

thanks!

All of these are appropriate medications for reducing blood pressure in patients with aortic aneurysms, but a beta-blocker should precede administration of nitroprusside. Without a beta-blocker, the reflex tachycardia associated with nitroprusside will increase dP/dT and shear forces, potentially extending the dissection.

Back when I was going through the 94 ITE and saw this question for the first time, I had the same question about NTG. You can certainly get reflex tachycardia with boluses of NTG, but presumably the test-writers were trying to make the point that that SNP (more arterial side action) causes more reflex tachy and is a greater risk than NTG (more venous side action).


previous thread

Also note that we have an ITE Keyword subforum which is a nice place to start threads like this.

 

[SleepIsGood]

All of these are appropriate medications for reducing blood pressure in patients with aortic aneurysms, but a beta-blocker should precede administration of nitroprusside. Without a beta-blocker, the reflex tachycardia associated with nitroprusside will increase dP/dT and shear forces, potentially extending the dissection.

Back when I was going through the 94 ITE and saw this question for the first time, I had the same question about NTG. You can certainly get reflex tachycardia with boluses of NTG, but presumably the test-writers were trying to make the point that that SNP (more arterial side action) causes more reflex tachy and is a greater risk than NTG (more venous side action).


previous thread

Also note that we have an ITE Keyword subforum which is a nice place to start threads like this.

Apparently d/t the dP/dT reasoning, this is why one should give Beta Blockers in extremely hypertensive pts with preeclampsia first prior to giving nitro.

 

[dillpickles]

thanks for the feedback and explanations, they helped