Hot topics in parenteral nutrition. Current evidence and ongoing trials on the use of glutamine in critically-ill patients and patients undergoing surgery.

The amino acid glutamine has numerous important roles including particularly antioxidant defence, immune function, the inflammatory response, acid-base balance and N economy. The present systematic review of randomised controlled trials of nutrition support with glutamine up to August 2008 has found that parenteral glutamine in critical illness is associated with a non-significant reduction in mortality (risk ratio 0.71 (95% CI 0.49, 1.03)) and may reduce infections. However, poor study quality and the possibility of publication bias mean that these results should be interpreted with caution. There is no evidence to suggest that glutamine is harmful in terms of organ failure and parenteral glutamine may reduce the development of organ failure.