The role of alternative lipid emulsions in critically ill patients: what the evidence shows.

Lipid emulsions (LEs) are a component of parenteral nutrition (PN) providing a dense source of energy and essential fatty acids. In critically ill patients, commonly used LEs have been rich in long-chain triglycerides (LCTs) providing a high percentage of linoleic acid (ω-6 polyunsaturated fatty acids [ω-6 PUFA] 18:2 ω-6). The current literature suggests that intravenous (IV) soybean-oil (SO) and safflower-based LEs are able to promote production of pro-inflammatory prostanoids and leukotrienes and therefore increase oxidative stress and systemic inflammation in the critically ill. In 2006, it was suggested that inclusion of ω-6-based LEs might be detrimental, which is more probable in the most seriously ill patients. Withholding lipid emulsion high in SO has been recommended in patients who tolerate some EN and who require short term PN (< 10 days).