Post-ICU plasma glutamine concentrations of patients (n = 49), admitted to the ICU and given exogenous intravenous glutamine supplementation together with full nutrition for >3 days. Patients were sampled on their last day of ICU stay (during ongoing intravenous supplementation) and thereafter every 5 to 7 days during the remaining hospital stay. All patients are depicted in (A). The reference interval used in the study, 400 to 930 μmol/L is indicated by gray shading. (B) only illustrates patients who were not readmitted to ICU (n = 35), where the nonsurvivors at 12 months (n = 7) are shown as red lines. (C) illustrates patients who were readmitted to the ICU (n = 14), nonsurvivors at 12 months (n = 8) are shown as red lines. Thick lines illustrate periods during which patients in this subgroup were again given intravenous glutamine supplementation during full feeding. ICU, intensive care unit.