Omega-6 sparing effects of parenteral lipid emulsions-an updated systematic review and meta-analysis on clinical outcomes in critically ill patients

Quirin Notz; Zheng-Yii Lee; Johannes Menger; Gunnar Elke; Aileen Hill; Peter Kranke; Daniel Roeder; Christopher Lotz; Patrick Meybohm; Daren K Heyland; Christian Stoppe

doi:10.1186/s13054-022-03896-3

Omega-6 sparing effects of parenteral lipid emulsions-an updated systematic review and meta-analysis on clinical outcomes in critically ill patients

Crit Care. 2022 Jan 19;26(1):23. doi: 10.1186/s13054-022-03896-3.

Authors

Affiliations

¹ Department of Anesthesiology, Intensive Care, Emergency and Pain Medicine, University Hospital Wuerzburg, Wuerzburg, Germany.
² Department of Anesthesiology, University of Malaya, Kuala Lumpur, Malaysia.
³ Department of Anesthesiology and Intensive Care Medicine, University Medical Center Schleswig-Holstein, Campus Kiel, Kiel, Germany.
⁴ Department of Anesthesiology and Intensive Care Medicine, University Hospital RWTH Aachen, Aachen, Germany.
⁵ Department of Critical Care Medicine, Queen's University, Kingston, Canada.
⁶ Clinical Evaluation Research Unit, Kingston General Hospital, Kingston, Canada.
⁷ Department of Anesthesiology, Intensive Care, Emergency and Pain Medicine, University Hospital Wuerzburg, Wuerzburg, Germany. christian.stoppe@gmail.com.

Abstract

Background: Parenteral lipid emulsions in critical care are traditionally based on soybean oil (SO) and rich in pro-inflammatory omega-6 fatty acids (FAs). Parenteral nutrition (PN) strategies with the aim of reducing omega-6 FAs may potentially decrease the morbidity and mortality in critically ill patients.

Methods: A systematic search of MEDLINE, EMBASE, CINAHL and CENTRAL was conducted to identify all randomized controlled trials in critically ill patients published from inception to June 2021, which investigated clinical omega-6 sparing effects. Two independent reviewers extracted bias risk, treatment details, patient characteristics and clinical outcomes. Random effect meta-analysis was performed.

Results: 1054 studies were identified in our electronic search, 136 trials were assessed for eligibility and 26 trials with 1733 critically ill patients were included. The median methodologic score was 9 out of 14 points (95% confidence interval [CI] 7, 10). Omega-6 FA sparing PN in comparison with traditional lipid emulsions did not decrease overall mortality (20 studies; risk ratio [RR] 0.91; 95% CI 0.76, 1.10; p = 0.34) but hospital length of stay was substantially reduced (6 studies; weighted mean difference [WMD] - 6.88; 95% CI - 11.27, - 2.49; p = 0.002). Among the different lipid emulsions, fish oil (FO) containing PN reduced the length of intensive care (8 studies; WMD - 3.53; 95% CI - 6.16, - 0.90; p = 0.009) and rate of infectious complications (4 studies; RR 0.65; 95% CI 0.44, 0.95; p = 0.03). When FO was administered as a stand-alone medication outside PN, potential mortality benefits were observed compared to standard care.

Conclusion: Overall, these findings highlight distinctive omega-6 sparing effects attributed to PN. Among the different lipid emulsions, FO in combination with PN or as a stand-alone treatment may have the greatest clinical impact. Trial registration PROSPERO international prospective database of systematic reviews (CRD42021259238).

Keywords: Critical illness; Fish oil; Immunonutrition; Omega-3 fatty acid; Omega-6 fatty acid; Parenteral nutrition.

Publication types

Meta-Analysis
Research Support, Non-U.S. Gov't
Systematic Review

MeSH terms

Critical Illness* / therapy
Emulsions
Fish Oils / therapeutic use
Humans
Parenteral Nutrition*

Substances

Emulsions
Fish Oils