Critical illness has been associated with glutamine (Gln) plasma levels depletion and its supplementation is related with better outcomes. In 2013 the Reducing Deaths due to Oxidative Stress (REDOXS) study, showed that the supplementation of Gln to total parenteral nutrition was associated with higher mortality without conferring beneficial effects. These conclusions had a high impact in the clinical field: two of the main guidelines downgraded its recommendation. However, recent studies are answering questions regarding the safety use of this amino acid use and even suggesting new potential beneficial effects.
It is important to understand the main lessons learned of the REDOXS study related to the correct use of Gln intra venous and do not rule out its use for the intensive care unit patients. The scientific community is actively working in the field and we expect to have more evidence to guide the correct of this amino acid in parenteral nutrition.