Effects of Long-Chain Triglyceride Emulsions on Reticuloendothelial System Function in Humans

Parenteral administration of long-chain triglyceride emulsions has been shown to have deleterious effects on reticuloendothelial system function in animal models. It is unknown whether this interference occurs in humans with clinically relevant doses of intravenous fat. Two studies were done. Eighteen patients were prospectively enrolled for study. Patients received full feeding by continuous total parenteral nutrition (amino acids 1.5 g/kg/day and dextrose 4.5 g/kg/day) with 33.1 kcal/kg/day. Forty-three % of the nonprotein calories were provided as soybean oil emulsion (Travamulsion 20%) and was administered intravenously over 10 hr (0.130 g/kg/hr). Reticuloendothelial system function was determined by measuring the change in the clearance rate of intravenously injected 99mTc-sulfur colloid (TSC) in each patient. In study 1 (n = 10), one day of lipid (10 hr) was infused, with the clearance of 99mTcsulfur colloid measured before the lipid was infused and then during the last hour of the 10-hr infusion. In study 2 (n = 8), the clearance rates were measured before the lipid emulsion was begun, and then during the last hour of the infusion on the 3rd day. Clearance rates for TSC after 10 hr of lipid infusion in study 1 did not differ (0.27 ± 1/min to 0.26 ± 0.1/min, p > 0.10). However, after 3 days of lipid infusion (10 hr/day), a statistically significant reduction in TSC was seen (0.46 ± 0.08/min-0.27 ± 0.03/min, p < 0.05). A decrease in the clearance rate of TSC after 3 days of intravenous lipid infusion but not after 1 day suggests that reticuloendothelial system function is impaired in a dose-response fashion when long-chain triglyceride emulsions are infused at clinically conventional rates. Long-term administration of intravenous long-chain triglyceride emulsion may be deleterious to optimal reticuloendothelial system function. (Journal of Parenteral and Enteral Nutrition 13:614-619, 1989)