Stress
Anesthesiology is a complicated business, and it's stressful to keep track of a lot of things at the same time—the right drug cocktail, the correct dosage, coordinating with the rest of the medical team. You know, just minor details like that.
And then there's that risk, teeny or humongous, that something may go wrong—the wrong drug cocktail, incorrect dosage, or failure to communicate. You know, things like that.
It could be stressful for neophytes to keep those t's crossed and those i's dotted, but consider what might happen if they don't. Death. Debilitation. Paralysis. Coma.
But you really don't want to think about these worst-case scenarios, especially on the job. Find a way to keep your mind clear and focused on the task at hand, and you should be just fine.