Intravenous fish oil lipid emulsions in critically ill patients: an updated systematic review and meta-analysis

INTRODUCTION: Intravenous fish oil (FO) lipid emulsions (LEs) are rich in ω-3 polyunsaturated fatty acids, which exhibit anti-inflammatory and immunomodulatory effects. We previously demonstrated that FO-containing LEs may be able to decrease mortality and ventilation days in patients who are critically ill. Since 2014, several additional randomized controlled trials (RCTs) of FO-containing LEs have been published. Therefore, the purpose of this systematic review was to update our previous systematic review with the aim of elucidating the efficacy of FO-containing LEs on clinical outcomes of patients who are critically ill. METHODS: We searched electronic databases from 1980 to 2014. We included four new RCTs conducted in critically ill adult patients in which researchers evaluated FO-containing LEs in parenterally or enterally fed patients. RESULTS: A total of 10 RCTs (n = 733) met inclusion criteria. The mean methodological score was 8 (range, 3 to 12). No effect on overall mortality was found. When we aggregated the results of five RCTs in which infections were reported, we found that FO-containing LEs significantly reduced infections (risk ratio (RR) = 0.64; 95% confidence interval (CI), 0.44 to 0.92; P = 0.02; heterogeneity I(2) = 0%). Subgroup analysis demonstrated that predominantly enteral nutrition–based trials showed a tendency toward a reduction in mortality (RR = 0.69; 95% CI, 0.40 to 1.18; P =0.18; heterogeneity I(2) =35%). High-quality trials showed a significant reduction in hospital length of stay (LOS) (weighted mean difference = −7.42; 95% CI, −11.89 to −2.94; P = 0.001), whereas low-quality trials had no effect (P = 0.45). The results of the test for subgroup differences in hospital LOS was significant (P = 0.001). CONCLUSION: FO-containing LEs may be associated with a reduction in infections and also could be associated with a reduction in duration of ventilation and hospital LOS. Further large-scale RCTs are warranted and should be aimed at consolidating potential positive treatment effects.