Cosigning Conundrum

I'm wondering what people think about my current predicament. I went to nursing school in one area of the country, and am now working in another area of the country. I was taught to consider cosigning as a nursing commandment (thou shalt always get a cosigner for insulin, heparin, narcotic wasting, etc)... I foolishly assumed that these rules were followed everywhere, but now that I'm working as a nurse, I realize that is not the case everywhere. When I went to administer insulin for the first time I asked my preceptor to cosign and was told, "No one does that here", and that though your're supposed to, no one does. After talking with several other people in my new grad class, I've found that this is a hospital wide problem. SO, people don't want to "bother" cosigning for insulin injections, but I'm also frequently doing insulin drips where I'm changing the rate of infusion every hour on multiple patients, and even the charge nurses are telling me you don't need a cosigner for that, which honestly makes no sense to me. I know I'm not going to mistakenly administer the wrong amount, but I am more concerned with the fact that even when you administer the correct amount that bad things can happen (i.e. hypoglycemia)... I'm working in an environment as a new nurse where I thought my preceptor was supposed to have my back..and I'm honestly feeling more that I have to watch my own back double-time due to the flagrant disregard for general nursing standards. I've addressed this issue in my new grad class, but the attitude I get from the nursing educators (most of whom are fairly young) is that it's my responsibility to go to my department educator and inform them of what's going on, but I also feel like they're trying to make a hospital wide problem way before I arrived my responsibility.....when I feel like this is something that needs to be corrected from the top down, and not the bottom up.... What do I do??? Thoughts please!!