Widodo Sarono eBook

Anesthesia, or anaesthesia (see spelling differences; from Greek αν-, an-, "without"; and αἴσθησις, aisthēsis, "sensation"), has traditionally meant the condition of having sensation (including the feeling of pain) blocked or temporarily taken away. It is a pharmacologically induced reversible state of amnesia, analgesia, loss of responsiveness, loss of skeletal muscle reflexes and/or decreased stress response. This allows patients to undergo surgery and other procedures without the distress and pain they would otherwise experience. The word was coined by Oliver Wendell Holmes, Sr. in 1846. Another definition is a "reversible lack of awareness," whether this is a total lack of awareness (e.g. a general anesthetic) or a lack of awareness of a part of the body such as a spinal anesthetic or another nerve block would cause.

Types of anesthesia
There are three different types of anesthesia; local anesthesia, regional anesthesia and general anesthesia. In local anesthesia a specific location of the body is numbed, such as the hand. Regional anesthesia numbs a larger area of the body by administering anesthesia to a cluster of nerves. Two frequently used regional anesthesia are spinal anesthesia and epidural anesthesia. General anesthesia describes unconsciousness and lack of any awareness or sensation.

Some good ebooks on Anesthesiology.