Ask any patient what their main worry is when having surgery and most will tell you, it's the anesthesia.
The American Society of Anesthesiologists says the most important thing you can do to protect yourself before surgery is to communicate. When you are asked to provide your full medical and family history, that means you have to be completely honest. If you ever smoke, drink, take drugs, legal or otherwise your anesthesiologist needs to know even if you take herbal remedies or something you think would have nothing to do with your procedure write it down.
"It could have a major impact on the outcome of the patient, and I would tell any patient who's having an operation to make sure they know their allergies and make sure that the anesthesiologists and the physicians caring for them know the allergies that the patient has," said Dr. Andrew Rosenberg, Anesthesiologist.
The ASA offers a checklist called "Anesthesia & Me". Even if you're not planning a surgery right now, that can help you organize the information you should know about yourself and your loved ones in case surgery is needed at some point. http://www.asahq.org.