I would not endanger myself or others when insisting to take out the IV but have you ever considered letting the police know about the patient. Have them go by the patients home to have it removed? I also live in a area where there are lots of drug abuse and we have patients leave with IV sites in. Can't help but be suspicious.
I am a manager of an ICU. Our staff approaches pts and familys about code status. If we left it to the docs it would never happen. All my staff do a wonderful job with this and the doctors appreciate the effort. I also think that nurses know who needs to be approached and who doesnt and i think that this comes with experience. Also i do not hesitate to ask because it is the pts choice!! and i feel proud to be there to offer this right to the pt. Remember that we are the pts advocate....