Metabolic evaluation of a 75% lipid/25% glucose high nitrogen solution for intravenous nutrition

To compare the metabolic response to a 75% lipid/25% glucose regimen of intravenous feeding with that of a regimen of isocaloric isonitrogenous glucose alone.

Randomised crossover study.

University department of surgery.

14 Patients (of 18 consecutive) who did not develop infections after major upper gastrointestinal operations.

Patients received five days of each of two regimens, both of which provided 0.38 g nitrogen and 0.155 MJ (37 kcal)/kg/day.

Nitrogen balance, prealbumin and transferrin concentrations, and basal efflux of amino acids from the lower limb before and after a five day course of each regimen.

Mean (SD) nitrogen balance increased from -11.4 (2.6) g/day to 1.7 (4.1) and 1.6 (5.5) g/day after lipid/glucose and glucose alone, respectively (p < 0.0001). Basal prealbumin and transferrin concentrations increased after both regimens, but significantly so only after lipid/glucose (p < 0.01 and < 0.02, respectively). Mean (SD) net basal efflux of total amino acids from the lower limb was significantly reduced after both regimens, (p < 0.0001 in each case). Net basal alanine efflux was significantly reduced only by glucose alone, and basal glutamine efflux only by lipid/glucose (p < 0.05 in each case). Plasma free fatty acids were increased only by glucose alone (p < 0.001), and glucose alone augmented tissue uptake of glucose significantly more than lipid/glucose (p < 0.01 and < 0.05, respectively).

The solution high in lipids and nitrogen was well tolerated. There was no difference in improvements in nitrogen balance or amino acid flux across the lower limb, but lipid/glucose was associated with higher increases in visceral protein concentrations.