[DP McCoy]

So I just got through watching Don't Look in the Basement(1973) and it reminded me of movie I watched some years ago,all I can remember is that it was set in a lunatic asylum possibly on a Island,where a psycho goes on the rampage.I don't think you see the killer to start with,just the aftermath of his initial killing spree,I remember someone finding a nurse in a corridor with a pair of surgical scissors sticking out of her neck,other than that I don't remember much else.I would imagine that the movie was made somewhere between the mid seventies and early eighties although I am not really sure.
There may have been more than one killer,I just can't remember:confused:
Any Ideas?