METABOLIC AND THERMOGENIC RESPONSE TO CONTINUOUS AND CYCLIC TOTAL PARENTERAL-NUTRITION IN TRAUMATISED AND INFECTED PATIENTS

16 traumatised or infected patients on mechanical ventilation were ran domised to continuous TPN or to cyclic TPN after a 24-h period of gluc ose infusion (1.25 kJ x kg BW-1 x h(-1)). Energy supply was equivalent to 1.3 x baseline energy expenditure. Glucose, fat and amino acids we re administered at a constant rate over 24 h in the continuous TPN gro up and over 12 h, followed by glucose (1.25 kJ x kg BW-1 x h(-1)), in the cyclic TPN group. Nutrientinduced thermogenesis was lower during c ontinuous than during cyclic TPN (5 +/- 4 vs. 12 +/- 7%, mean +/- SD, p < 0.05), as was the increase in CO2 elimination (13 +/- 11 vs. 30 +/ - 7%, respectively, p < 0.01). Energy balance was more positive during continuous TPN. In both groups, energy expenditure reached a plateau during the first 12 h of TPN infusion. The lower nutrient-induced ther mogenesis and more positive energy balance, indicates a more efficient utilisation of nutrients during continuous than during cyclic TPN. Th e lower CO2 production during continuous TPN, may be advantageous when respiratory function is compromised. The plateau in energy expenditur e in response to TPN infusion may be useful as a guideline for nutriti onal therapy.