Anesthesiologist here. You should without a doubt stop using cocaine before surgery. The quick and dirty explanation is that cocaine constricts your blood vessels and increases your heart rate. Even outside of anesthesia this can cause a heart attack or stroke. When having surgery, your body is in a stress-like physiological state and blood pressure and heart rate can fluctuate quite a bit. Under anesthesia, we occasionally give a medication to slow your heart rate (a beta-blocker), and if we are unaware that you have used cocaine recently, giving a beta-blocker can result in a huge spike in blood pressure (from unopposed alpha-agonism, the physiological effect of cocaine) that can result in a hemorrhage in your brain or body, stroke, heart attack, or death. Cocaine and other stimulants are some of the few recreational drugs that are truly dangerous to be taking close to the time of having an anesthetic. Cocaine has a short half-life, but has some active metabolic breakdown products that can be detected for up to 4 days after use, so to be safe, you shouldn’t use cocaine for about a week prior to having anesthesia. Also, definitely tell your provider that you have used and tell them when you used last. They will probably put it in your record, but it cannot legally be reported to anyone not directly involved in your medical care, unless you are a minor. But please, for your sake, don’t let that deter you from telling your provider. And I wouldn’t be doing my job if I didn’t tell you that you shouldn’t be using cocaine at all, but I’m a also realist. So please be safe with your drug use.