Board Exam Questions

[drlee]

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1993 ITE Question 8:

An increased initial dose and a decreased maintenance dose of pancuronium are required in pts with:

a) advanced age
b) burns
c) cirrhosis
d) chronic renal failure
e) fever

Answer: C

Pts with cirrhosis have an increased volume of distribution due to increased extracellular fluid volume and have slower rate of drug clearance due to liver dysfunction. Pancuronium, though primarily dependent on the kidneys for excretion, is dependent on the liver for metabolism. The answer is understandable.
Let's assume the patient has chronic renal failure. They also have an increased volume of distribution but primarily due to fluid retention. Wouldn't these pts also require an increased initial dose and a decreased maintenance dose? 😕

 

[BISof60]

i liked it better when each of these questions had their own heading.

 

[dfk]

hey jet, drlee's looking for ya again...

 

[Intrathecal]

Was hoping someone can help with this 1993 question:

Which of the following statements concerning the cardiovascular effects of IV bupivacaine is true?

A. Bretylium is effective in treating bupivacaine induced ventricular dysrhythmias
B. Cardiovascular toxicity is reduced during pregnancy
C. Cardiovascular toxicity occurs at lower blood levels than central nervous system toxicity
D. Systemic vascular resistance is unchanged
E. The rate of impulse conduction through the heart is increased

I picked answer C, since it has been beaten into my brain during residency that bupivacaine can cause cardiovascular collapse before any CNS symptoms can develop.

According to the ABA, the answer is A.

What gives?

 

[pgg]

I picked answer C, since it has been beaten into my brain during residency that bupivacaine can cause cardiovascular collapse before any CNS symptoms can develop.

The issue with bupivacaine is that the margin between CNS symptoms and CV collapse is smaller than with other local anesthetics. But CNS toxicity still typically manifests first.

 

[Gern Blansten]

Clearly a dated question. Their answer, while at the time may have been okay, is probably not the best answer today. I am not even sure you can still get bretylium.
That being said, the other answers are not correct. I don't recall that anything has been positively shown to effectively treat bupivacaine induced ventricular dysrhythmias. Lipid 20% emulsion has been shown to be effective in animals and a handful of human case reports.