The role of ω-3 fatty acid supplemented parenteral nutrition in critical illness in adults: a systematic review and meta-analysis

Objective: To determine whether the supplementation of parenteral nutrition with ω-3 fatty acids confers treatment benefits to critically ill adult patients.

Data Source: We performed computerized searches for relevant articles from 1996 to June 2011 on MEDLINE, EMBASE, and the Cochrane register of controlled trials and abstracts of scientific meetings from 2005 to 2011.

Study Selection: Randomized controlled trials of ω-3 fatty acid supplemented parenteral nutrition in critically ill adult patients admitted to the intensive therapy unit, given in addition to their routine care, compared with parenteral nutrition without ω-3 fatty acid supplementation.

Data Synthesis: Five fully published trials and three trials published in abstract form with 391 participants have been included. Overall trial quality was poor. Mortality data were pooled from eight studies with 391 participants. No differences were found with a risk ratio for death of 0.83 (95% confidence interval 0.57, 1.20; p = 0.32). Data for infectious complications were available from five studies with 337 participants. No differences were found, with a risk ratio for infection of 0.78 (95% confidence interval 0.43, 1.41; p = 0.41). Data for intensive therapy unit and hospital length of stay were available from six and three studies with 305 and 117 participants, respectively. With respect to intensive therapy unit length of stay, no differences were observed with a mean difference of 0.57 days in favor of the ω-3 fatty acid group (95% confidence interval –5.05, 3.90; p = 0.80). A significant reduction in hospital length of stay of 9.49 days (95% confidence interval –16.51, –2.47; p = 0.008) was observed for those receiving ω-3 fatty acid supplemented parenteral nutrition, but results were strongly influenced by one small study.

Conclusions: On the basis of this systematic review, it can be concluded that ω-3 fatty acid supplementation of parenteral nutrition does not improve mortality, infectious complications, and intensive therapy unit length of stay in comparison with standard parenteral nutrition. Although ω-3 fatty acids appear to reduce hospital length of stay, the poor methodology of the included studies and the absence of other outcome improvements mean they cannot be presently recommended.