Veterinarians are NOT Engineers

Pharmacology today was definitely a demonstration of how differently engineers and other scientists think.


We had to do some pretty basic drug calculations before class this morning. (Things like if you have 50% dexamethasone solution and you want to make 450 mL of 2.5% dexamethasone solution, how many mL of stock solution would you have to add to your saline?) In class, we went over the answers to the questions. First, it took 45 minutes to do 3 simple problems, which was bad enough.

Second, it was just so... haphazard. She just rambled along on the board writing down numbers WITHOUT units. In engineering, that's a HUGE no-no. If you're going to make an error in your calculations (or find it easily once you do), it's often because you flubbed the units somewhere. You either didn't do the conversion factor right (multiplied by pounds/kilograms rather than dividing by kilograms/pounds or something) or you are using the wrong units somewhere (liters instead of milliliters or something) for example.

Even worse to my sensibilities, she kept calculating out intermediate quantities, which is introducing a completely unecessary level of rounding error into your problem. And while that's often not a big deal, it can make anywhere between a couple tenths to a couple orders of magnitude difference! And with some drugs, even a couple tenths of a gram/millilter/whatever can be devastating. Then she was going on and on about how sometimes you need to back correct for volume added affecting your final concentration (which can be a big problem. But if you're worried about that, how are you not worried about rounding error?!) I mean, basically, the more times you enter numbers into your calculator, the more wrong your answer is. That's the whole point of dimensional analysis! (Besides that it's an easy way to track units.)



Just... incredibly frustrating!


And then, we did a clicker question where she gave us all metric values... and wanted the answer in ounces. When we asked for the conversion factor from mL to oz, she refused to give it. Really? I mean, in practice we can google that if the pharmacy really insists on oz. And really, who does that?! Medicine happens in metric, folks. (Besides, if I want to convert units like that, google is an excellent tool. Go ahead, enter "209 mL in ounces" into google... It will tell you "209 mL = 7.06713074 US fluid ounces." Thanks, Google, old pal!)