Local anesthesia
Local anesthesia is any technique to induce local analgesic effect or the absence of sensation in part of the body that would be insensitive to pain, although other local senses may be affected as well. It is used in patients for surgical and dental procedures and in many situations like cesarean section where it is safer and therefore superior to general anesthesia. It is also used for relief of non-surgical pain and to enable diagnosis of the cause of some chronic pain conditions. It works by blocking the nerves from the affected part of the body so that the signals are not able to reach the brain. Hence the pain during the surgery is not felt. It generally takes a few minutes to lose the feeling in the area and it takes a few hours for the feeling to come back. There are several types of local anaesthesia such as Topical, Infiltration anaesthesia, Nerve blocks, Intravenous regional block, Plexus block and Extradural and spinal anaesthesia. Sometimes both general and local anesthesia techniques are combined and used. There are two classes of local anesthetics: aminoamide and aminoester local anesthetics. Local anesthetics are used in various techniques like Topical anesthesia (surface), Infiltration, Plexus block, Epidural (extradural) block and Spinal anesthesia (subarachnoid block). Because of the short duration of the anesthesia effect of local anesthetics, it is primarily used for minor outpatient procedures in which the patient can leave on the same day of surgery.