Enteral omega-3 fatty acid supplementation in adult patients with acute respiratory distress syndrome: a systematic review of randomized controlled trials with meta-analysis and trial sequential analysis

Abstract

Purpose Controversy remains as to whether enteral supplementation of ω-3 fatty acids (FA) could improve outcomes in patients with acute respiratory distress syndrome (ARDS). Thus, we did a meta-analysis and aimed to investigate the benefit and harm of enteral ω-3 FA supplementation in adult patients with ARDS. Methods Databases including PubMed, Embase, the Cochrane Register of Controlled Trials, and Google Scholar were searched to find relevant articles. Randomized controlled trials (RCTs) comparing enteral ω-3 FA supplementation with a control or placebo intervention in adult patients with ARDS were included. The primary outcome was all-cause 28-day mortality. We used the Cochrane Collaboration methodology. Results Seven RCTs with 955 adult patients qualified for inclusion, and all the selected trials were considered as at high risk of bias. The use of enteral ω-3 FA did not significantly reduce all-cause 28-day mortality [relative risk (RR), 0.90; 95 % confidence intervals (CI), 0.68-1.18; p = 0.44; I (2) = 31 %; random effects]. Trial sequential analysis indicated lack of firm evidence for a 20 % RR reduction in all-cause 28-day mortality. PaO2/FiO2 ratio was significantly increased in the ω-3 FA group on day 4 [weighted mean difference (WMD), 45.14; 95 % CI, 16.77-73.51; p = 0.002; I (2) = 86 %; random effects] and day 7 (WMD, 33.10; 95 % CI, 1.67-64.52; p = 0.04; I (2) = 88 %; random effects). Meta-analysis using a random effects model showed no significant differences in ventilator-free days (VFD) (WMD, 2.47 days; 95 % CI, -2.85 to 7.79; p = 0.36; I (2) = 91 %) or intensive care unit-free days (ICU) (WMD, 2.31 days; 95 % CI, -2.34 to 6.97; p = 0.33; I (2) = 89 %) between the two groups. Conclusions Among patients with ARDS, enteral supplementation of ω-3 FA seemed ineffective regarding all-cause 28-day mortality, VFD, and ICU-free days. Routine use of enteral ω-3 FA cannot be recommended based on the available evidence.