Effects of a continuous lipid infusion on glucose metabolism in critically ill patients

The effects of lipid administration on carbohydrate oxidation rate remain controversial, particularly in critically ill patients. The aim of this study was to determine the effects of these patients of a continuous lipid infusion on glucose metabolism using indirect calorimetry and stable isotopes. We studied seven patients, mechanically ventilated, during two consecutive 24-h periods. Throughout the first period they received a continuous infusion of glucose (2 mg.kg-1.min-1) and amino acids. During the second period, in addition to the glucose, they received a continuous infusion of 1 mg.kg-1.min-1 of long-chain triglycerides emulsion. Substrate oxidation rates were calculated from pulmonary gas exchange and nitrogen excretion measurements. Glucose kinetic parameters were measured using primed constant infusions of [6,6-2H2]glucose and [1-13C]glucose. The lipid infusion did not modify the glucose metabolism parameters; 45% of the lipid supply was stored.