This is an ongoing problem which should be resolved. Some working environments are stuck in a pointless past. There really is no reason whatsoever to require psd files over a live working responsive prototype made with html and css. With psds plenty of things are left to interpretation and it’s an impossibly cumbersome job to extract all necessary dimensions, colours etc in an accurate and efficient manner. Defining % based layouts in photoshop is simply STUPID. Photoshop is NOT an interface design tool, the advantages of real protoyping are just way too many to mention.
I’ve been in your situation before and I fought hard to stop the psd stupidity, in most instances I managed to convince my client using hard facts. The main one being that working with psds is ultimately way more expensive, every little design change takes considerably more time and if we talk about bigger changes… really no contest. Now let’s navigate a psd with 100’s of layers all tucked away in their little folders, very efficient-not. The alternative of using dev tools to instantly access the markup you require with one click is a winner that no one can argue against.
As I said, if all other reasoning fails the price one is one that all managers understand.
Good luck with it.