Advances in intravenous lipid emulsions

Over the past decade, our vie rvs have considerably evolved with respect to the metabolism of intravenous lipid emulsions and their composition. Subst antial progress has been made in understanding the metabolic pathways of em ulsion particles and the delivery of their various components (fatty acids and vitamins) to specific tissues or cells. Although soybean long-chain tri glycerides represent a valuable source of energy, concerns have been raised about their high content of polyunsaturated fatty acids (mainly n-6 essent ial fatty acids), which may adversely affect immune functions and antioxida nt status. Introduction of medium-chain triglycerides or olive oil to lipid emulsions can largely help bypass these disadvantages. Recently, incorpora tion of n-3 fatty acids in lipid preparations was suggested to have potenti al application in several chronic and acute diseases because of their abili ty to reduce inflammatory and thrombotic responses and cell sensitivity to various stimuli. Hence lipid emulsions should no longer be considered only as a means of providing energy substrates; they also modulate key metabolic functions. Such improved knowledge may lead to optimizing the metabolic ca re of certain patients.