SBA Paper

Question 1

Why does Rocuronium have a more rapid onset than Vecuronium?

Answer 1

Rocuronium has a lower potency, therefore a higher dose is required required for intubation will enhance the diffusion gradient between plasma and neuromuscular junction (Bowman principle).

Question 2

Equation to calculate initial plasma drug concentration after an IV bolus?

Given this initial plasma concentration = 100mcg
.If you were required to calculate the concentration after 1 minute, 2 minutes?

Answer 2

Initial concentration = Dose/Vd
Must always convert to micrograms and millilitres

For 1 minute and 2 minutes you need the rate constant elimination ie k = 0.1.
This is a percentage.
If initial dose is 100 mcg.
After one minute you minus 10% = 90mcg
After two minutes 90 - (0.1 x 90) = 81 mcg

Question 3

Therapeutic effect of botulinum toxin?

Answer 3

Inhibition of acetylcholine release.

toxin released from clostridium botulinum

Question 4

Action of Macrolides such as clarithromycin?

Answer 4

Inhibition of protein synthesis

by binding to the ribosome and interfering with translocation.

Question 5

In pressure-volume curves, what is the best indication of work of breathing? Ie. acute asthma attack

Answer 5

The work of breathing is best indicated by the area within the hysteresis loop.

Ie. a larger hysteresis loop

Question 6

In an experimental situation, a giant squid axon is bathed in an electrolyte solution containing chloride, potassium and sodium ions.

Which change in extracellular ion concentration would have the greatest effect in making the resting membrane potential less negative?

Answer 6

Increasing potassium ion concentration.

The question simply tests knowledge of the Nernst equation and the fact that the resting membrane is relatively impermeable to sodium.

Question 7

Formula for kinetic energy?

Answer 7

kinetic energy = 1/2 mv(sq)

Question 8

Formula specific heat capacity?

Answer 8

= mass x SHC x temperature change

Question 9

Potential energy of lifting an object?

Answer 9

mass x gravity x height

Question 10

Formula for electrical energy

Answer 10

I x V x seconds

Question 11

At what point after a burns injury must succinylcholine not be given?

Answer 11

Can be given within the first 24 hours, not after 24 hours since injury.