Surgical nurses can explain the procedure to the patient and ease fears about the upcoming surgery and recovery. They also check the patient's vital signs, administer medications and help sterilize and mark the surgical site. The nurse may give instructions and must be followed to ensure your safety. Here are some examples: Do not eat or drink anything (including water) after midnight the night before surgery. Do not eat or drink anything (including water) the morning of surgery. Don't chew gum. Refrain from smoking at least 24 hours before surgery. Do not drink alcoholic beverages for at least 48 hours beforehand