Virtually all surgical procedures require anesthesia of one type or another. The type and duration of an anesthetic is dependent upon the procedure to be performed, the depth of unconsciousness required and the part of the body to be operated upon.
While surgeries involving the extremities may do well with general anesthetics or regional blocks, procedures involving the abdominal contents or other vital organs may require deeper anesthesia and profound muscle relaxation, if not complete paralysis.
General Anesthesia
General anesthesia is that type of anesthesia that renders the patient unconscious for the purpose of performing surgery in a painless environment. Agents combined in a general anesthetic include intravenous narcotics, intravenous anti-anxiety drugs, intravenous anesthetic agents and, occasionally, paralytic agents--those that cause paralysis of muscle fibers for complete relaxation.
These intravenous agents are used for the initial stage of anesthesia, called the induction phase. Once the patient is asleep, the level of unconsciousness is maintained primarily with the use of Inhalant agents, those that are breathed in. Different types of inhalants are used for different situations.
Spinal Anesthetic
Spinal anesthetics are administered by way of a needle that is inserted into the spinal sac of the lumbar spine area, usually between the bony processes of the vertebral column, through which injectable anesthetic agents are administered. These agents numb the nerve tracts located within the spinal sac, thus causing the body parts that are served by these nerves to become numb.
There are different agents that are used depending upon the duration of anesthesia needed for surgery. This anesthesia type is primarily used for surgical or obstetric procedures performed below the belly button.
Local Anesthetic
The term "local anesthetic" describes an anesthetic that numbs a very specific area of the body for surgical procedures that involve a rather small area when complete unconsciousness is not required. Local anesthetics are typically administered via injection into tissue surrounding the area to be operated upon, thus rendering it numb.
Different types and compositions of local anesthetics are used, depending upon the body part to be operated upon as well as the duration of anesthesia desired.
Nerve Block
A nerve block can be considered a type of local anesthetic, with the main difference being the ability to inject the same local anesthetic agent(s) at a remote location from the surgical site, and by infiltrating the agent(s) around the nerve(s) that serve the intended surgical site, provide anesthesia without disrupting the tissue at the surgical site with infiltration of the local anesthetic.
This anesthetic type is particularly useful when a larger area of a body part is targeted for anesthesia and a local anesthetic would be insufficient to produce the desired results.
