Hi, yes I have had back problems for years, I am know going to the back dr. for surgery, I havent seen him yet, but am told you have to quit smoking before they will operate. Weell, as a smoker I want to smoke as long as I can before I have to stop and be able to pass the blood test . thank you How long will nicotine stay in my system and other chemicals to pass this test, I know I have to the surgery, but at the same time, I dont want to quit until the very last minute, Im sure you can understand