Tuesday, January 25, 2011

ICU Rounds Report - Jan 25th 2010

ICU and Fish Oils - More than standard hype from Reader's Digest?

UPDATE 1/25/11 - The omega piece of the EDEN-Omega trial was stopped for futility. While we're still awaiting publication, it appears omega 3 are standard reader's digest hype...

Lot and lots (and lots!) of studies have been done looking at various nutritional supplements for feeding critically ill patients. Usually based on good ideas and exciting pre-clinical data, almost universally, they have disappointed. On possible except: omega-3 fatty acids in ARDS. In little mice and rabbits given ARDS, omega-3 fatty acids have antiinflammatory and vasodilatory properties that improve gas exchange, heal pathological microvascular damage and improve hemodynamics. The first humanRCT was done in 1999 on patients with severe ARDS using Opexa (a proprietary blend of omega-3s and antioxidants) versus 'standard' feeds. It looked great: better oxygenation, less time on the ventilator (11 vs. 16.3 days; p = .011), less time in the ICU  (12.8 vs. 17.5 days; p = .016) and less new organ failure (p = .015). Unfortunately, in point of fact, that trial used a non-standard formula as a control that was unusually high in potentially toxic omega-6 fatty acids, which made the results questionable and was widely dismissed.

But then two subsequent (sponsored by industry!) RCTs using proper standard feeds as controls were also positive. The results were the same, or better - better oxygenation, less ventilator time, lower length of stay and, in the more robust trial (i.e. double blinded) patients feed the Opexa have a 20% reduction in mortality (p = .037). Two larger, independent studies (i.e. the thousand patient EDEN-Omega Study) have recently been completed with publication expected this year that will hopefully settle this question, but for now I believe the preponderance of evidence argues for using Opexa in patients with ARDS.
Gadek JE,et al. Effect of enteral feeding with eicosapentaenoic acid, gamma-linolenic acid, and antioxidants in patients with acute respiratory distress syndrome. Enteral Nutrition in ARDS Study Group.
Crit Care Med. 1999;27(8):1409-20.
Singer P, Benefit of an enteral diet enriched with eicosapentaenoic acid and gamma-linolenic acid in ventilated patients with acute lung injury. Crit Care Med. 2006;34(4):1033-8.
Pontes-Arruda A, Effects of enteral feeding with eicosapentaenoic acid, gamma-linolenic acid, and antioxidants in mechanically ventilated patients with severe sepsis and septic shock. Crit Care Med.

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