Elsevier

Nutrition

Volume 61, May 2019, Pages 84-92
Nutrition

Review
Omega-3 polyunsaturated fatty acids in critically ill patients with acute respiratory distress syndrome: A systematic review and meta-analysis

https://doi.org/10.1016/j.nut.2018.10.026Get rights and content

Highlights

  • Omega-3 polyunsaturated fatty acids have been administered to ARDS patients, mostly by enteral route with contradictory results.

  • Enteral immunomodulatory diets with fish oils may be associated with an improvement in early and late PaO2-to-FiO2 ratio in ARDS, although a clinical and statistically significant heterogeneity exists.

  • The treatment effect seems to be greatest in those trials published before 2011 that provided an immunomodulatory formula with fish oils administered as a continuous infusion.

  • Further well-powered clinical trials aimed at evaluating whether modulating pathophysiology of ARDS patients with omega-3 could improve morbidity and mortality are warranted.

Abstract

Objective

Acute respiratory distress syndrome (ARDS) is characterized by an acute inflammatory response in the lung parenchyma leading to severe hypoxemia. Because of its anti-inflammatory and immunomodulatory properties, omega-3 polyunsaturated fatty acids (ω-3 PUFA) have been administered to ARDS patients, mostly by the enteral route, as immune-enhancing diets with eicosapentaenoic acid, γ-linolenic acid, and antioxidants. However, clinical benefits of ω-3 PUFAs in ARDS patients remain unclear because clinical trials have found conflicting results. Considering the most recent randomized controlled trials (RCTs) and recent change in administration strategies, the aim of this updated systematic review and meta-analysis was to evaluate clinical benefits of ω-3 PUFA administration on gas exchange and clinical outcomes in ARDS patients.

Methods

We searched for RCTs conducted in intensive care unit (ICU) patients with ARDS comparing the administration of ω-3 PUFAs to placebo. The outcomes assessed were PaO2-to-FiO2 ratio evaluated early (3–4 d) and later (7–8 d), mortality, ICU and hospital length of stay (LOS), length of mechanical ventilation (MV), and infectious complications. Two independent reviewers assessed eligibility, risk of bias, and abstracted data. Data were pooled using a random effect model to estimate the relative risk or weighted mean difference (WMD).

Results

Twelve RCTs (n = 1280 patients) met our inclusion criteria. Omega-3 PUFAs administration was associated with a significant improvement in early PaO2-to-FiO2 ratio (WMD = 49.33; 95% confidence interval [CI] 20.88–77.78; P = 0.0007; I2 = 69%), which persisted at days 7 to 8 (WMD = 27.87; 95% CI 0.75–54.99; P = 0.04; I2 = 57%). There was a trend in those receiving ω-3 PUFA toward reduced ICU LOS (P = 0.08) and duration of MV (P = 0.06), whereas mortality, hospital LOS, and infectious complications remained unchanged. Continuous enteral infusion was associated with reduced mortality (P = 0.02), whereas analysis restricted to enteral administration either with or without bolus found improved early PaO2 and FiO2 (P = 0.001) and MV duration (P = 0.03). Trials at higher risk of bias had a significant reduction in mortality (P = 0.04), and improvement in late PaO2-to-FiO2 ratio (P = 0.003).

Conclusions

In critically ill patients with ARDS, ω-3 PUFAs in enteral immunomodulatory diets may be associated with an improvement in early and late PaO2-to-FiO2 ratio, and statistical trends exist for an improved ICU LOS and MV duration. Considering these results, administering ω-3 PUFAs appears a reasonable strategy in ARDS.

Keywords

Omega-3
Fish oil
Acute respiratory distress syndrome
Gas exchange

Cited by (0)

Conflict of interest: P.L.L. received speaking honorarium from Fresenius Kabi. G.H. and W.M. have received financial reimbursement from Baxter Healthcare for consultancy work, advisory boards, and speaking engagements. F.D.A. has no conflict of interest to declare.

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