Intravenous lipid emulsion therapy – The fat of the land

SummaryLocal anaesthetic agents are utilised ubiquitously in clinical practice, and as such potentially grave adverse events such as systemic toxicity can occur. Although the use of ultrasound, and nerve stimulator guided administration have reduced the risk of such adversities, they unfortunately have not been eliminated. This review examines the pharmacology and toxicology of local anaesthetic agents and the use of Intravenous Lipid Emulsion (ILE) to counteract the systemic toxic effects. The research underpinning the ‘Lipid Sink’ and ‘Lipid Flux’ theories of ILE mechanism of action are explored, as is the novel and successful use of ILE in other lipophilic drug toxidromes, such as overdoses of tri-cyclic antidepressants and calcium channel antagonists. Also discussed are the potential direct and indirect risks associated with the use of intravenous lipid treatments and the possibility for reporting bias in the literature. Despite this, case reports of the successful use of ILE are certainly compelling, and have led to the rapid adoption of ILE in clinical practice and the recommendation for its use by anaesthetic associations worldwide.