Local anaesthetic systemic toxicity

Abstract

Access the CPD MCQs for this issue online here ### Key points Well-placed local anaesthetics (LAs) can yield great clinical benefits. But systemic toxicity related to their use can be devastating. The highly publicized case in 2004 of Mayra Cabrera, a theatre nurse who died shortly after delivery of her baby boy when her epidural infusion of bupivacaine was mistakenly connected to her i.v. line, reminds us to be vigilant and to learn from such rare events. While prevention is clearly the most important element in avoiding morbidity and mortality associated with local anaesthetic systemic toxicity (LAST), such cases still occur despite best practice. Knowing how to manage these uncommon events is vital. In this review, we cover LA toxicity, its incidence, clinical features, risk factors, prevention, and management and examine i.v. lipid emulsion (ILE) therapy in more detail. LAST has been recognized for more than a hundred years, but the precise incidence is currently unknown. In 1928, the American Medical Association reported 40 deaths attributable to LAs.1 Cocaine was responsible for half of these deaths, but procaine was also implicated. These findings prompted the search for less toxic agents. Lidocaine, first synthesized in 1944, was the first amide LA to be used clinically. However, in 1979, the potentially fatal toxicity of amide LAs was highlighted by Albright.2 More recently, studies from 1993 …