I recently found a better suggestion than the way I was cutting my elderly hamsters nalils. I had him on some mesh and stuck a carrot up through so while he was munching i could snip the tips from under. I found a video by our own Vectis hams where she uses a bird feeder. Much better and wish I had thought about it!
How to Trim Hamster Nails: the Mesh Method - YouTube
Good luck at the vets