Nerve damage can results from general anesthesia, local anesthesia and regional anesthesia. While the cause of damage varies, it can range in severity from mildly annoying to disabling. In most cases, the damage is temporary and the discomfort or numbness decreases in the weeks following surgery. But a small percentage of patient have lasting nerve problems.
During local or regional anesthesia, damage can occur when medications are injected into a nerve and either the syringe or the medication used for the injection injures the nerve tissue. Damage can also occur during a spinal epidural, one type of regional anesthesia, if the spinal cord is injured by the injection of anesthetics.
Nerve damage can also result during general anesthesia, if the patient is placed in a position that when medication if the patient is lying in a position for extended periods of time that block blood flow to the nerves. An example of this type of damage is the “pins and needles” sensation when a leg is “asleep.” A person that is awake can stand up or move to relieve the problem, but a patient who is under anesthesia does not know there is a problem and cannot move.