One of the residents came up to the desk where I was sitting the other night, and said hello, introduced himself, and then brightly asked if we had any reflex hammers in the ER he could borrow for his exam. The conversation went kind of like this:
First-year Resident: Hey there, bummer of a busy night eh? By the way, is there a reflex hammer down here that I can borrow real quick?
Resident: Uhhh...no seriously...
Resident: Yeah, I guess I should have brought mine in tonight. I was running late and forgot to grab it.
I felt kind bad for just laughing at him, but when I explained that not only do we not have reflex hammers but are also lacking PowerLoc needles, foley kits, a working tube system, enough staff to work any given day, and cardiac monitor lead stickers, he realized that a hammer was just not on the priority list at all. Plus I gave him my stethoscope to use instead and also foisted a plate of cookies on him to take back upstairs, so I think I smoothed things over well enough.
But lesson learned: the ER won't ever have anything you need or the right sort of thing you want, so bring it yourself to save you the grief.