Are you currently an MS3? I wouldn't necessarily say this is a late change per se. Still plenty of time before MS4 year starts. With that being said, I don't think you necessarily have to rush out and get working on an anesthesia related research project. I personally don't have any, the stuff I did was in other areas (and hardly any to speak of really) and it hasn't seem to hurt me, but I'll let you know for sure after Math Day. 😛 Some of the more research heavy places I interviewed just seemed to care that you were capable of doing something and at least working towards a publication. It sure can't hurt to have some though, that's for sure. 😀