Getting a Chance

I have been a Registered Nurse for three years. My career started out in Family Practice Clinic. Currently I am working on the SNF unit at a reputable hospital. However, I have been trying to get in to a specialty for the last few months. My main interests are the OR and PAC-U. I have had interviews for various positions only to be turned down. My hopes have been shattered. I feel like I am at a dead end job without any hope of getting out. I am very unhappy where I am and dread going into work. I felt I needed experience working the floor but would like a position in a specialty unit. This seems almost impossible to do and I feel trapped. What does it take to get into a specialty? Any advice or suggestions would be much appreciated.