Nutritional support in per operative period: the use of lipid solutions

Energy deficit is a common and serious problem in major surgical patients and is associated with increased rates of complications, length of stay, and mortality. Parental nutrition (PN), either alone or in combination with enteral nutrition, can improve nutrient delivery to this kind of patients. Lipids provide a key source of calories within PN formulations, preventing or correcting energy deficits and improving outcomes. In this article, we review the role of parenteral lipid emulsions (LEs) in the management of patients undergone to major surgical procedures and highlight important biologic activities associated with lipids. Soybean-oil-based LEs with high contents of polyunsaturated fatty acids (PUFA) were the first widely used formulations in the surgical setting. More recently developed parenteral LEs employ partial subsostitution of soybean oil with oils providing medium-chain triglycerides, omega-9 monounsaturated fatty acids or omega-3 PUFA. Manyof these LEs have demostrated reduced effects on oxidative stress, immune responses, and inflammation. Ongoing research using adequately designed and well-controlled studies that characterize the biological properties of LEs should assist clinicians in selecting LEs within the surgical setting.