My considerations regarding the embarassment I felt during a pimp session have ultimately led to an inevitable truth: I should have known this material.
Whether it resulted from my not reading as much as necessary (I had been reading about this the night before, but fell asleep with my CMDT lying fitfully on my stomach and didn't get it in the ol' brain) or the reduction in patient and floor-type care contact, I don't know. I believe, however, that the atrophy of my knowledge was a direct result of various interactions.
For one, I have not had to deal with heart care in more than a year except in the OR - where the care is decidely more acute, with different drugs and algorithms being employed. In fact, I, along with hundreds of 4th years, haven't had much to do with medicine at all in many months. No matter how much you read something, if you're not involved to some degree beyond printed text you get stale.
Another factor is that I have been taking some time for leisure: reading fiction, music, working out, etc. Medicine has been at a back burner for a few weeks and it's hard to dust off the cobwebs sometimes.
Yet, in this humiliating and seemingly frustrating week I've learned something profound that has, until now, not been fully realized: You need residency training to become a doctor. Simple, right? But it's often so easy to think that we're coasting, doing well, and that residency is too hard and too long just to get a little ahead of where you're at now, so why do we really need it? Then you have moments like this and think "Not so" - the nature of trying to do something, failing, being called out, and then going over the scenario and reading about the current treatments helps create an impression in your brain that wasn't there before and would never have existed except through experience. And that's what it's all about.