The type of anesthesia an anesthetist uses during surgery will depend on the length and type of surgery, the patient's state of health, and the preference of the anesthetist.
There are four types of anesthesia:
General anesthesia is the strongest anesthesia - it is essentially a medically induced coma which makes the patient unresponsive during surgery. This allows the surgeon to perform surgeries that would normally be very painful if the patient were to be awake. Because this type of anesthesia paralyzes the muscles of the body, patients require a ventilator to do the job of the diaphragm.
Unlike general anesthesia where the patient is unconscious and the whole body is paralyzed, local anesthesia allows the patient to stay awake during the procedure. This type of anesthesia is used for minor procedures that can be completed in a short time, such as dental procedures or for numbing an area that needs to be stitched. The patient typically returns home the same day.
Regional anesthesia only numbs the area of the body that would feel pain, which enables the patient to have the procedure while they are still awake or sedated. Examples of this type of anesthesia are spinal or epidural blocks, where sensations in the lower body are blocked by injecting anesthesia near the spinal canal. This is different from local anesthesia in that a larger region of the body is numbed.
Monitored Anesthesia Care (MAC)
Monitored Anesthesia Care (also known as conscious sedation or twilight sleep), will make a patient sleepy and calm during a procedure. This type of anesthesia is given through an IV, and the level of sedation can range from light (patient is very relaxed), to heavier (patient only responds to significant stimulation). This type of anesthesia is different from general anesthesia in that the patient is not chemically paralyzed and does not require assistance with breathing - however their vital signs are closely monitored.
This type of sedation is used for procedures such as colonoscopies, endoscopies, dental procedures, bronchoscopies, eye surgeries, and pain management procedures. The patient is typically expected to go home after the anesthesia has worn off.