Local Anesthetics and Local Anesthetic Systemic Toxicity (LAST) in Relation to Obstetric Anesthesia

The use of low doses of local anesthetics and incremental injections will decrease the incidence of LAST. Most cases of LAST follow a typical progressive pattern of presentation with a combination of CNS and cardiovascular symptoms. The first and most common signs and symptoms are related to CNS toxicity, primarily in the form of a seizure. Prodromal signs such as perioral paresthesia, agitation, and audiovisual disturbances have also been described as early manifestations in a few patients. One-third of the reported cases progress to involve the cardiovascular system with dysrhythmias, conduction defects, hypotension, and arrest.