Newsletter

[ Vol. 12 No. 1 ] (January - April 2011 )
Glutamine and selenium in critical care

Gil Hardy
Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand

The clinical efficacy of the conditionally essential amino acid, glutamine (GLN) as an enteral (EN) or parenteral (PN) pharmaconutrient is now well demonstrated by systematic reviews of PRCT. GLN deficiency is common in those who remain ill for more than a few days and may result in impaired immune function, which increases susceptibility to infectious complications and sepsis. Low plasma GLN levels also correlate with mortality. GLN-PN therapy at 20-30g/day results in fewer days of mechanical ventilation and reduced incidence of pneumonia in ICU patients. Long stay GLN patients survive because they develop fewer infections and are less likely to die from multiple organ failure.

GLN-EN can improve intestinal barrier function, maintain immune competence and may have advantages in promoting closure and more rapid healing of postoperative high-output intestinal fistula.

Combination PN/EN GLN therapy is an increasingly powerful nutritional weapon in the fight against inflammation, infection and some cancers. GLN is the primary energy substrate for immune and gut epithelial cells, and an important precursor of glutathione (GSH). Reactive oxygen species, which are active in cancer and other diseases, are scavenged by GSH which plays an important antioxidant and detoxification role. Oxidative stress, and low GSH levels may be associated with inadequate intake of Selenium (Se), a key constituent of the enzyme Glutathione Peroxidase (GPx). High dose Se supplementation reduces mortality in the critically ill, but it is postulated that optimal levels of GPx cannot be maintained, when stores of rate-limiting GSH or its substrate GLN, become exhausted. There may be a therapeutic synergy between Se and GLN-enriched PN. This hypothesis is currently being investigated in the SIGNET and REDOXS trials. Both studies seek to reduce infectious complications and improve patient outcome.

From   
PENSA 2009
“Energizing Nutrition Support Practice for Life”
June 5-7 2009, Shangri-La Hotel, Kuala Lumpur, Malaysia 
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