The efficacy of a 20 per cent fat emulsion as a peripherally administered substrate.

Physicians and industrial biochemists involved in the development and trial of disease specific amino acid formulations and adjustments in nonprotein calorie to nitrogen ratios consistently emphasize the need for discriminate clinical use of variations from standard formulations and ratios of substrates. The decision to manipulate substrate content must be based upon the metabolic state of each individual patient. Despite these recommendations, there appears to be a tendency to try innovative therapy in patients not fully meeting the criteria for disease specific TPN. A standard mix of postoperative patients commonly found on surgical services were entered into this protocol. Three randomly assigned variations in nonprotein calorie to nitrogen ratios were secondarily tested under carefully controlled conditions. The results indicate that 20 per cent lipid solution is a useful adjunct in TPN regimens, since twice the number of calories can be delivered in one-half the fluid volume. Fat solutions alone or in combination with isotonic concentrations of dextrose did not consistently produce positive nitrogen balance when given with significantly different nonprotein calorie to nitrogen ratios.