Fish oil in the critically ill: from experimental to clinical data

Purpose of review The aim of this paper is to describe recent relevant literature concerning the role of n-3 lipids derived from fish oil in clinical nutrition in an intensive care setting. Recent findings N-3 fatty acids compete with arachidonic acid for metabolism to lipid mediators and exert profound effects on second mediator generation and dependent cellular functions. In experimental models, dietary and parenteral use of fish oil was shown to protect the gut by increasing its perfusion. In contrast, use of immunonutrition including fish oil in critical ill patients or patients with severe sepsis may exert an excess mortality. Using parenteral fish oil in surgical patients promising data became available. In septic patients, immunologic effects of fish oil-based lipid emulsions have been found and intravenous supplementation with fish oil may have a beneficial impact on mortality and length of stay. For both patient groups, however, prospective data from randomized trials are lacking. Summary N-3 lipids exhibit strong immunologic properties. They offer the possibility to counterbalance the negative effects of conventional n-6 fatty acids. Recent studies exhibit positive effects of intravenous use of fish oil on immunologic functions and clinical parameters in surgical and septic patients.