This is a prospective double-blinded placebo-controlled block randomised study in intensive care patients comparing intravenous glutamine supplementation (0.285 g/kg body weight/24 h) to placebo. Inclusion criteria are patients treated for more than 3 days. Primary endpoint is a reduction in SOFA-score on day 7 of treatments. Secondary endpoints are: ICU-mortality, 6-months mortality, length of ICU stay, organ failure free days as well as reduction in SOFA-score on day 10 of treatment. Nutrition will be standardised so that not less than 80% of the target which is basal energy expenditure according to Harris & Benedict is given daily. Enteral nutrition is preferred, but a combination of enteral and parenteral nutrition is recommended to achieve the nutritional target. For statistical comparison non-parametric rank order statistics will be used. To detect a 0.75-point difference in the reduction of SOFA-score on day 7 of treatment, a total of 1,000 patients will be needed.