Intravenous lipid emulsions and host defense — a critical review

Malnutrition, secondary to deficiency of energy, protein or essential fatty acids, is associated with reduced host defense and increased incidence or severity of certain infections (1, 2). These and other consequences of malnutrition constitute the rationale for administering total parenteral nutrition (TPN), a measure that has been shown to reduce post-operative infections and other surgical complications (3. 4). During the 70s and SOS, concern was expressed that TPN, given in order to replete or maintain energy and nutritional stores, and to support host defense mechanisms in critical illness. might have the opposite effect and cause further impairment of host defense. Interest was focused in particular on possible detrimental effects of parenterally administered lipids. This review attempts to summarise the evidence concerning intravenous fat emulsions and the immune system.