Parenteral structured triglyceride emulsion improves nitrogen balance and is cleared faster from the blood in moderately catabolic patients

Background: Most postoperative patients lose net protein mass, which reflec ts loss of muscle tissue and organ function. Perioperative parenteral nutri tion may reduce the loss of protein, but in general, with conventional lipi d emulsions a waste of protein still remains. Methods: We compared the effe cts on nitrogen balance of an emulsion containing structured triglycerides, a new type of synthesized triglycerides, with an emulsion of a physical mi xture of medium- and long-chain triglycerides as part of parenteral feeding in moderately catabolic patients. The first 5 days after placement of an a ortic prosthesis patients received total parenteral nutrition (TPN) providi ng 0.2 g of nitrogen per kg body weight per day; energy requirement was cal culated using Harris and Benedict's equation, adding 300 kcal per day for a ctivity. Twelve patients were treated with the structured triglyceride emul sion and 13 patients with the emulsion of the physical mixture of medium- a nd long-chain triglycerides. The design was a randomized, double-blind para llel study. Results: In the patients who completed the study, the mean cumu lative nitrogen balance over the first 5 postoperative days was -8 +/- 2 g in 10 patients on the structured triglyceride emulsion and -21 +/- 4 g in 9 patients on the emulsion of the physical mixture of medium- and long-chain triglycerides; the mean difference was 13 g of nitrogen (95% confidence in terval 4 to 22, p = .015) in favor of the structured triglyceride emulsion. On the first postoperative day serum triglyceride and plasma medium-chain free fatty acid levels increased less during infusion of the structured tri glyceride emulsion than with the physical mixture emulsion. Conclusions: Th e parenteral structured triglyceride emulsion improves the nitrogen balance and is cleared faster from the blood, compared with the emulsion of the ph ysical mixture of medium- and long-chain triglycerides, in moderately catab olic patients.