This brings up several questions about the most appropriate filtration for infusing all parenteral nutrition solutions. When all components are admixed together in one solution container (ie, 3-in-1 or Total Nutrient Admixture), the recommendation has always been to use an in-line 1.2-micron filter for infusion. IVFE will not pass through filters with a smaller pore size. The concern was and still is cracking the fat emulsion, possibly resulting in a fat embolism.
What about filtration for a 2-in-1 solution containing protein, carbohydrates, and other additives? The practice has been to use a 0.2-micron filter on this solution to ensure removal of all particulate matter and microorganisms. IVFE was piggybacked below the filter or given through a separate catheter with no filtration. Now the IVFE requires a 1.2-micron filter regardless of where it is infused.
There are several options for configuring the filters. According to 2016 INS Standards of Practice and a 2014 ASPEN guidelines document, a 0.22-micron filter is needed for the 2-in-1 PN solution due to particulates from the compounding process and microorganisms that could enter the system. To follow these new IVFE manufacturer instructions, 2 filters of 2 different sizes must be used - a 1.2-micron filter on the IVFE and a 0.22 micron filter on the 2-in-1 PN.
The other option would be to use a 1.2-micron filter in the system and infuse both 2-in-1 PN and IVFE thru the same filter. This could be considered the same as infusing a 3-in-1 PN solution thru a 1.2-micron filter.
To make the clinical decision about filters, I would want to know what filtration, if any, was done by the pharmacy during the compounding process. If pharmacy is filtering, what pore size filter is being used? To reduce microbial contamination, I would strictly enforce the policy of NOTHING being injected or piggybacked into this system and the system would ONLY be taken apart when it is time to change the entire administration system once every 24 hours.