Hang Time for 3-in-1 TPN Solutions
The hang time for 3-in-1 (all-in-one) TPN admixtures should not exceed 24 hours from the time of hanging, with the giving set changed upon each new dosing. 1
Standard Hang Time Recommendations
The American Society for Parenteral and Enteral Nutrition establishes a maximum 24-hour hang time for home parenteral nutrition admixtures, which applies to all-in-one formulations containing lipids, amino acids, and dextrose. 1
This 24-hour limit is critical because lipid peroxidation occurs within 24 hours after compounding, making this the primary limiting factor for stability of 3-in-1 admixtures. 2
Vitamins degrade at different rates after compounding, with fat-soluble vitamins showing significant degradation beyond 24 hours at infusion temperature (37°C), further supporting the 24-hour hang time limit. 3
Storage vs. Hang Time Distinction
It's essential to distinguish between storage stability and hang time:
3-in-1 admixtures supplemented with vitamins and trace elements can be stored refrigerated (2-8°C) for up to 7 days when protected from light. 4
Once removed from refrigeration and hung for infusion at room temperature, the 24-hour clock begins, regardless of how long the bag was previously stored. 1, 3
At room temperature (25°C) with light exposure, supplemented 3-in-1 PN remains stable for only 48 hours maximum, but the conservative 24-hour hang time recommendation accounts for infusion at body temperature (37°C). 4
Key Stability Factors
The 24-hour limit is driven by multiple chemical and physical processes:
Lipid particle size remains stable, with no clinically significant coalescence occurring during the 24-hour infusion period at room temperature. 5, 6
Chemical stability, particularly vitamin degradation and lipid peroxidation, is the limiting factor rather than physical emulsion breakdown. 2
Alpha-tocopherol (vitamin E) shows approximately 24% loss within 24 hours, and other vitamins interact and degrade at varying rates. 3, 2
Critical Safety Considerations
Cold chain maintenance is mandatory from compounding through transport to the point of administration, with bags stored at 4°C until immediately before use. 7
The giving set must be changed with each new bag to prevent bacterial contamination and maintain sterility. 1
Continuous agitation should be avoided, as it may actually hasten lipid breakdown and cause visible oil layer formation by 72 hours. 5
Filtration during delivery does not extend hang time but may be used for additional safety without affecting lipid particle stability. 5