Toxicity of local anaesthetic agents

SummaryLocal anaesthetic agents can cause neurotoxicity, myotoxicity and systemic toxicity. The mechanisms of direct neurotoxicity and myotoxicity are similar and independent of sodium channel blockade. Systemic local anaesthetic toxicity can cause serious morbidity and mortality, the incidence appears to be stable despite the hope that widespread use of ultrasound for regional anaesthesia would reduce its incidence. Occurrence of systemic local anaesthetic toxicity is reliant on the interaction between patient characteristics, the rate of rise and the plasma level of local anaesthetic achieved. There is also differential cardiac toxicity dependent on the particular local anaesthetic agent. The most significant advancement in the treatment of local anaesthetic toxicity is the introduction of lipid emulsion. However, there still have been few case reports of successful use and the mechanism of action is yet to be clarified.