Nerve injury associated with regional anesthesia.

Neural damage is a possible consequence of general anesthesia, central nervous system blockade, and regional anesthesia. Dainage may be caused by ischaemic and mechanical or chemical factors, which may occur either alone or in combination. Neural damage may be secondary to prolonged and severe arterial hypotension compromising blood supply to the cord, a spinal haematoma whose main etiological factor is a coagulation abnormality, an intraneural injection, and peripheral neuropathy related to perioperative positioning. Mechanical trauma by the needle bevel is an important factor contributing to neuropathy. Neurological complications may also result from a direct neurotoxic effect of local anesthetic agents which is concentration and dose-dependent. A better understanding of these mechanisms will provide a reliable basis for the development of improved pharmaceutical therapy.