Intravenous fish oil in adult intensive care unit patients

Omega-3 fatty acids contained in fish oils have shown efficacy in the treatment of chronic and acute inflammatory diseases due to their pleiotropic effects on inflammatory cell signalling pathways. In a variety of experimental and clinical studies, omega-3 fatty acids attenuated hyperinflammatory conditions and induced faster recovery. This chapter will shed light on the effects of intravenous fish oil in adult intensive care unit (ICU) patients and will discuss clinical data and recent meta-analyses on the topic. While significant beneficial effects on infection rates and the lengths of ICU and hospital stays have concordantly been identified in three recent meta-analyses on non-ICU surgical patients, the level of evidence is not so clear for critically ill patients. Three meta-analyses published in 2012 or 2013 explored data on the ICU population. Although the present data suggest the consideration of enteral nutrition enriched with fish oil, borage oil and antioxidants in mild to severe acute respiratory distress syndrome, only one of the three meta-analyses found a trend (p = 0.08) of lower mortality in ICU patients receiving intravenous omega-3 fatty acids. Two of the meta-analyses indicated a significantly shorter hospital stay (5.17-9.49 days), and one meta-analysis found a significant reduction in ICU days (1.92). As a result of these effects, cost savings were postulated. Unlike in surgical patients, the effects of fish oil on infection rates were not found to be statistically significant in ICU patients, and dose-effect relationships were not established for any cohort. Thus, obvious positive secondary outcome effects with intravenous fish oil have not yet been shown to transfer to lower mortality in critically ill patients. There is a need for adequately powered, well-planned and well-conducted randomized trials to give clear recommendations on the individual utility and dosage of intravenous omega-3 fatty acids in critical illness.