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.