Lipid emulsions in parenteral nutrition.

Lipid emulsions containing a physical mixture of medium and long chain triglycerides (MCT/LCT) are a well-proven concept in parenteral nutrition of critically ill patients. Having a demonstrably higher utilization rate, MCT/LCT emulsions do not impair liver function, produce less immune and no reticuloendothelial system function compromise, and do not interfere with pulmonary hemodynamics or gas exchange. A reduced content of n-6 polyunsaturated fatty acids can also be obtained by using newer preparations based on structured triglycerides or olive oil. Further studies are necessary in order to investigate these new lipid emulsions versus the physical mixture of MCT/LCT. A promising substrate in the development of lipid emulsions can be seen in fish oils. With regard to current literature, fish oils have a beneficial influence on the pathophysiological response to endotoxins and exert important modulations on eicosanoid and cytokine biology. Furthermore their intravenous use may improve organ perfusion in different critical situations.