What is Anesthesia?   The word ‘anesthesia’ means ‘loss of sensation’ with or without loss of consciousness.    Types of Anesthesia: There are many types of anesthesia in use today: general anesthesia, regional anesthesia, monitored anesthesia care, local anesthesia and major nerve blocks.  In addition, sedation medication may be used before and/or during various forms of anesthesia for the patient’s comfort.   GENERAL ANESTHESIA causes loss of consciousness prior to and during the operation. During general anesthesia anesthetic medications are injected into the bloodstream after placement of an intravenous line, and/or anesthetic gases may be breathed into the lungs.  When these medications are carried to the brain by the blood, they produce unconsciousness.  Other medications are given to prevent pain and there may be medications given to relax the muscles of the body.  During general anesthesia, it is always necessary to support patient breathing because of the depression of breathing activity from unconsciousness.  In this case there will be a breathing tube or other artificial airway device placed in the patient’s mouth or throat after the loss of consciousness.  At the end of surgery, as the anesthetic drugs are stopped and begin to wear off, the patient regains consciousness and normal muscle strength.   REGIONAL ANESTHESIA is the injection of local anesthetic to numb a certain region of the body.  Local anesthetic drugs are injected near the bundles of nerves which carry signals from that region of the body to the brain.  The most common regional anesthetic techniques are spinal and epidural anesthesia.  Spinal or epidural anesthetics are sometimes used for surgical procedures done below the level of the chest, such as Caesarean section or surgery on the lower extremities.  Other types of regional anesthesia are sometimes used for shoulder, arm or hand procedures.  During a regional anesthetic the patient may remain conscious, but unable to feel the anesthetized region.  Additional sedation may be given if needed to help the patient relax or sleep comfortably, but an airway device is usually not necessary.   MAC (Monitored Anesthesia Care) is a term referring to the use of intravenous administration of sedative drugs.  This technique is most appropriate for procedures requiring sedation but not unconsciousness. During the procedure, the anesthesiologist/anesthetist will deliver varying amounts of sedative medication through an intravenous (IV) line, monitoring the patient's comfort level and increasing or decreasing medication as needed.  This type of anesthesia is commonly referred to as “twilight sleep”, and does not provide the same deep unconsciousness as general anesthesia.  No airway device is usually needed, but the patient may dream, or have some recollection of conversation, movement, or music.   LOCAL ANESTHESIA is a technique where local anesthetic medication is injected before a procedure to dull the pain.  It is given as a shot in several places in and around the surgery area.  The shot helps to numb the small nerves in that area.  Under local anesthesia, the surgeon injects the area just before the start of the operation.   The patient may remain awake or be sedated, depending on what is needed. Any sedation is provided intravenously by an attendant anesthesiologist or anesthetist. Local anesthesia lasts for a short period of time and is often used for minor outpatient procedures.     PERIPHERAL NERVE BLOCKS and PLEXUS BLOCKS are an injection of local anesthetic given around the nerve or nerves supplying the feeling to the area being operated on.  It is usually administered as a single injection.  The duration of the numbness in the area depends on the local anesthetic chosen, but can be from two to eighteen hours.  These nerve blocks are usually used to decrease pain after surgery. The nerve that is blocked depends on the location of surgery you are having.  Usually additional sedation or a general anesthetic will be used as well to allow the patient to be asleep or relaxed.   INTRAVENOUS REGIONAL ANESTHESIA is an injection of local anesthetic given into the veins of an extremity (arm or leg) while a tourniquet is applied above the injection site to keep the anesthetic within the area below the tourniquet.  When the tourniquet is released at the end of the surgical procedure, feeling and movement return to the area immediately.  Additional sedation is usually required to ensure the patient is relaxed and comfortable.  This technique is best used for minor superficial procedures on the hand or foot, and should not be used for procedures lasting more than an hour.