General anesthesia is when an anesthesiologist uses a combination of medicines in order to render you completely unconscious, and insensitive to the pain from your operation. Anesthesia medications may be given in two forms; intravenously, where medications are given through an IV, or with gases that are breathed through an anesthesia mask or breathing tube (endotracheal tube). Intravenous medications typically take 10-20 seconds before you fall asleep. For children that do not have an IV, the induction of anesthesia is usually by breathing anesthesia gases (mixed with oxygen) through a mask. After the child falls asleep (usually in about 30 seconds), an IV is started, and other medications may be administered through the IV, such as those to prevent pain and nausea, are given during the general anesthetic. When your anesthesiologist decides to place an endotracheal tube in you, you will most likely be receiving inhaled gases and IV medications during your surgery. Patients are frequently put on an anesthesia ventilator during their surgery. At the end of the operation, the endotracheal tube is removed.