Immuno-nutrition worse than useless?

ImmunonutritionHeyland, SIGNET, REDOXS, ARDNSNET’s OMEGA, INTERSEPT, and now the Metaplus study. 

Approximately  300 patients, critically ill (APACHE >15) and ventilated were all given high protein (>1.2g/Kg/day), normal calorie (25Kcal/Kg/day) feed, either with or without Omega-3 acids, glutamine and antioxidants. All were started within 48 hours and stopped within 28 days.

No benefit in terms of length of stay or days on the ventilator. No difference in infection. No difference in subgroups except for an increase in adjusted (for age and disease severity) 6 month mortality amongst the medical patients.

Whilst most agree on high protein feeding, and initial permissive hypocaloric (~trophic) nutrition, evidence on the remaining contents is unclear. Regarding micronutrients Selenium recently performed well, but otherwise there have been no convincing and repeatable successes. And now it looks like the current batch of immuno-nutrition candidates have fallen short. Vitamin D is currently ‘research en-vogue’ but not yielding impressive results even at the basic science level, evident in another paper this week.

Moreover, the ‘ventilated patient’ is a heterogeneous set. Nutrients have been given enterally in some trials and parenterally in others. As always, larger studies in more defined subgroups are yet to happen.