Nitrogen sparing effect of structured triglycerides containing both medium-and long-chain fatty acids in critically ill patients; a double blind randomized controlled trial

Background and Aims: Patients with sepsis and trauma are characterised by h ypermetabolism, insulin resistance and protein catabolism. Fat emulsions co ntaining medium chain triglycerides have been suggested to be beneficial fo r these patients since medium chain fatty acids are a more readily availabl e source of energy when compared to long chain fatty acids. The aim of this study was to compare a medium and long chain triglyceride emulsion consist ing of structured triglycerides (ST) with a long chain triglyceride (LCT) e mulsion in terms of effects on nitrogen balance, energy metabolism and safe ty. Methods: 30 ICU patients with sepsis or multiple injury received a fat emul sion with ST or 20% LCT (1.5 g triglycerides/ kg body weight/day) as a comp onent of total parenteral nutrition (TPN), for 5 days in a double blind ran domised parallel group design. The main analysis was made on the 3 day per protocol population due to lack of patients at day 5. Results: There were no differences in baseline characteristics of the two g roups receiving either the LCT or the ST emulsion,The efficacy analysis was performed on the per protocol population (n = 9 ST, n = 11 LCT). There was a significant difference between the two treatments regarding daily nitrog en balances when the first 3 days were analysed P = 0.0038). This resulted in an amelioration of the nitrogen balance on day 3 in the group on ST as c ompared to those on LCT (0.1 +/- 2.4 g vs -9.9 +/- 2.1 g P = 0.01). The 3 d ay cumulative nitrogen balance was significantly better in the group receiv ing ST compared to those on LCT ( -0.7 +/- 6.0 vs -16.7 +/- 3.9 P = 0.03). This better cumulative nitrogen balance on day 3 was also preserved as a te ndency (P = 0.061) in the analysis of the intention to treat population, bu t on day 5 there was no significant difference (P = 0.08). The ST emulsion was well tolerated and no difference was found compared to the LCT emulsion regarding respiratory quotient, energy expenditure, glucose or triglycerid e levels during infusion. Conclusion. Administration of a structured triglyceride emulsion resulted i n an amelioration of nitrogen balance despite no effect on energy expenditu re in short term administration over 3 days to ICU patients when compared t o a long chain triglyceride emulsion. No side effects linked to medium chai n triglycerides were noted. (C) 2001 Harcourt Publishers Ltd.