[Energy substrates in parenteral nutrition]

Preparation of fine emulsified fat particles without glycerol for intravenous nutrition

A method of preparing fine emulsified fat particles without glycerol for intravenous nutrition was investigated. The factors assessed were the oil phase ratio, the glucose level of the aqueous phase and the temperature of high-pressure homogenization. The particle size decreased with an increase in the oil phase ratio and it went below 250 nm only in the emulsion with a 50% oil phase ratio. The weight-weighted particle size (dw)/number-weighted particle size (dn) value reflected the particle size distribution. The emulsion with a 50% oil phase ratio had a very narrow distribution of particle sizes and the dw/dn value was below 1.1. With the use of glucose solutions for the aqueous phase, smaller particle sizes and narrower distributions were obtained with increasing glucose concentrations. The controlled temperature of 50 degrees C was appropriate for high-pressure homogenization, producing particles below 160 nm. The rate of the layer separation was a function of particle size. The particle sizes below 180 nm can be expected to suppress the separation of the formulation which consisted of 10.0% soybean oil, 1.2% phospholipids and 5.0% glucose. The stability studies were conducted at 40 degrees C for 3 months and the fat emulsion was stable during storage. These investigations contribute to the preparation of a new caloric source for peripheral parenteral nutrition.

Liver and biliary tract changes and injury associated with total parenteral nutrition: pathogenesis and prevention

Total parenteral nutrition (TPN), now widely used, is successful in preventing and reversing malnutrition in individuals with various diseases and conditions. However, hepatic and biliary complications of TPN are encountered in both adult and pediatric patients. Certain complications, such as sepsis and TPN-associated cholestasis, occur more frequently in very young infants. Continuing problems commonly seen in adults are steatosis and steatonecrosis. Reasons for the development of these complications are multifactorial. Etiologies of hepatic complications, especially the role of deficiency/excess of nutrients in the pathogenesis of hepatobiliary disorders, are summarized. Complications caused by the duration of TPN are discussed with emphasis on prevention and management. Evidence now suggests that prompt enteral feeding, even in minimal amounts, may prevent many of the metabolic complications associated with TPN. TPN should be used only in amounts meeting needs and for a duration essential to survival.