Intravenous lipid emulsion – rescued at LAST

Abstract

The accidental overdose of local anaesthetics may prove fatal. The commonly used amide local anaesthetics have varying adverse effects on the myocardium and beyond a certain dose all are capable of causing death. Local anaesthetics are the most frequently used drugs in dentistry and although uncommon, local anaesthetic systemic toxicity (LAST) accounts for a high proportion of mortalities in the dental office, with local anaesthetic-induced cardiac arrest particularly resistant to standard resuscitation methods. Over the last decade there has been convincing evidence of using intravenous lipid emulsions as a rescue in local anaesthetic - cardiotoxicity and anaesthetic organisations over the globe have developed guidelines on the use of this drug. Despite this, however, awareness among practitioners appears to be lacking. All who use local anaesthetics in their practice should have an appreciation of patients at high risk of toxicity, early symptoms and signs of toxicity, preventative measures when using these drugs and the initial management of systemic toxicity with intravenous lipid emulsion. In this review we intend to discuss the pharmacology and pathophysiology of local anaesthetic toxicity, and the rationale for intravenous lipid emulsion therapy.