I did and I just got a lot of waffle.
I think every hospital has a process where you can write/email a body who deal with the complaints procedure. Check on hospital website.
Even though I didn't get much satisfaction, (they wanted to send my husband home with a broken pelvis after two days. I said that I wanted Social Sevices involved and backup when I got home. There was no way I could lift an eleven stone man in and out of bed etc. They backed down and kept him for ten days and organised physio both in hospital and afterwards.), I was glad that I did it. It might make them review their policies towards future patients.
One last piece of advice: try to concentrate on just one main complaint. If you throw in the kitchen sink, it will only dilute your case. And, unless a staff member was particularly negligent, try to avoid naming names. The hospital board will then hold this person totally responsible instead of fixing the bigger proble. Good luck. Let us know how you get on.
Ps keep copies of all correspondence and notes of times and dates of phone calls.