Lipid rescue resuscitation from local anaesthetic cardiac toxicity

Abstract

Systemic local anaesthetic toxicity is a rare but potentially fatal complication of regional anaesthesia. This toxicity is due to inhibition of ionotropic and metabotropic cell signal systems and possibly mitochondrial metabolism. It is associated with CNS excitation and, in the extreme, refractory cardiac dysfunction and circulatory collapse. Infusion of lipid emulsion has been shown in animal models to reliably reverse otherwise intractable cardiac toxicity and the mechanism of lipid rescue is probably a combination of reduced tissue binding by re-established equilibrium in a plasma lipid phase and a beneficial energetic-metabolic effect. Recent case reports have suggested the clinical efficacy of lipid infusion by the recovery of patients from intractable cardiac arrest. Future areas of investigation will focus on improved treatment regimes and better understanding of the mechanism of lipid rescue, which might allow superior alternative therapies, or treatment of other toxic events. An educational website has been established to help disseminate information about lipid emulsion therapy and to serve as a medium for physicians to share experiences or thoughts on the method and local anaesthetic toxicity.