The importance of the use of filters during the infusion of parenteral nutrition containing lipid emulsions

Abstract

Parenteral nutrition preparations supplemented with lipid emulsions may present physicochemical alterations characterized by the formation of amorphous or crystalline precipitates and by an increased size of fat droplets, which aggregate. A macroscopic verification of these changes is not always possible because of the opaque aspect of the emulsions. The objective of the present in vitro study was to determine the presence of calcium phosphate precipitates, of fat droplets of the lipid emulsion with wider diameters than red blood cells in parenteral nutrition preparations and the importance of the use of filters for the retention of such
precipitates. These events were demonstrated by macroscopic and microscopic inspection of parenteral nutrition preparations containing potassium dibasic phosphate and calcium gluconate as a source of phosphorus and calcium, respectively, added to the mixture of amino acid solutions at the proportion of 10% (w/v), with 50% glucose (w/v), a 20% lipid emulsion (w/v) and minerals at different proportions. The results showed the presence of a calcium precipitate and of enlarged and/or aggregated fat droplets before filtration, and their absence immediately after filtration. Conclusion:the use of filters with 1.2 mm pores was sufficient to retain the precipitates and to prevent the passage of fat droplets with dimensions that might cause microvascular embolism in patients submitted to parenteral nutrition.