If general anesthesia is utilized, the anesthesiologist will begin the process of converting you from a normal waking state to a drowsy condition of anesthesia. This is known as induction, and it is often accomplished by either injecting drugs through an IV or breathing gases through a mask. The anesthesiologist may also be able to achieve this same result with only local anesthesia if necessary. Once you are under the influence of anesthesia, doctors will use various methods to try and wake you up without causing further damage to your brain. These methods include oxygenation via mask or cannula, coughing, mechanical stimulation (such as shaking), and finally injection of a drug called atropine. Atropine is used because it works on all types of anesthesia, it does not cause other problems when administered during surgery, and it can always be reversed if needed. Anesthesiologists generally attempt to keep you asleep during surgery so that you do not feel anything important is happening. They may also want to avoid having you wake up too soon after they stop administering drugs, since this might cause you to lose muscle tone and possibly fall out of bed unassisted. After surgery is complete and you have recovered from any associated injuries, your anesthesiologist will again attempt to wake you up for removal from the anesthesia machine. This is usually done by increasing the amount of oxygen flowing into your blood stream via a cannula or mask.