I am having weight loss surgery and need to pass a nicotine test how long do i have to be smoke free for it to be undetected in my blood? cotitine too

For any type of: surgery, you have to quit smoking regardless, because you at risk of atelectasis, or your lungs (partial or full collapse) post surgically, and it reduces your microcirculation & healing to the area. You can't smoke after surgery either. So to have the best results, the longer you are nicotine free before and after surgery,the better your recovery, 4 weeks before and after surgery, meaning 8 wks.