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Total parenteral nutrition is the final option for nutritional support of patients with severe intestinal failure. Lipid emulsions constitute the main source of fuel calories and fatty acids (FAs) in parenteral nutrition formulations. However, adverse effects on patient outcomes have been attributed to the use of lipids, mostly in relation to impaired immune defenses and altered inflammatory responses. Over the years, this issue has remained in the limelight, also because technical advances have provided no safeguard against the most daunting problems, ie, infectious complications. Nevertheless, numerous investigations have failed to produce a clear picture of the immunologic characteristics of the most commonly used soybean oil--derived lipid emulsions, although their high content of n--6 polyunsaturated FAs (PUFAs) has been considered a drawback because of their proinfiammatory potential. This concern initiated the development of emulsions in which part of the n--6 FA component is replaced by less bioactive FAs, such as coconut oil (rich in medium-chain saturated FAs) or olive oil (rich in the n--9 monounsaturated FA oleic acid). Another approach has been to use fish oil (rich in n--3 PUFA), the FAs of which have biological activities different from those of n--6 PUFAs. Recent studies on the modulation of host defenses and inflammation by fish-oil emulsions have yielded consistent data, which indicate that these emulsions may provide a tool to beneficially alter the course of immune-mediated conditions. Although most of these lipids have not yet become available on the US market, this review synthesizes available information on immunologic characteristics of the different lipids that currently can be applied via parenteral nutrition support. KEY WORDS Total parenteral nutrition, lipid emulsion, immunology, inflammation, fatty acids, eicosanoids

A study was conducted to describe basal and exercise-induced systemic oxidative stress and acute inflammatory response in healthy subjects, non-muscle-wasted chronic obstructive pulmonary disease (COPD) patients, and muscle-wasted COPD patients. This showed that both maximal and submaximal exercise encourage increased systemic inflammatory and oxidative responses in muscle-wasted CPOD patients compared with non-muscle-wasted patients and healthy subjects.