6 months ago I returned to hospital nursing after nearly 2 years at home with young children and 7 years away from the hospital (I had worked in a dialysis clinic after leaving the hospital).
I can't say it was easy; I felt that if I had been away from nursing for any longer than 2 years, I would have needed a refresher course. I'm in an acute dialysis unit, and that part (dialysis) wasn't hard since I had the experience; however, we also have to deal with hospital charts, orders, Pyxis (the med dispensing system that didn't exist 7 years ago), and other "hospital stuff".
In general, hospital nursing hasn't changed that much. To be honest, I'm glad to be back in a hospital - it gives me more options (chronic dialysis was too specialized).
After 13 years, it may be harder - you may have to take a refresher course. But I encourage you to give it a try. As for patient loads, this varies a lot from department to department. In OB (L&D) it may be 1:1, as it is in acute dialysis. And no, you don't need to know Spanish
Good luck, let us know what you decide to do.