Evaluation of "Closed" vs "Open" Systems for the Delivery of Peptide-Based Enteral Diets

David R. Wagner, MS

Indianapolis Gastroenterology Research Foundation
Michael F. Elmore, MD
Indianapolis Gastroenterology Research Foundation
Donna M. Knoll, MS, RD, CNSD
Saint Francis Hospital Center, Beech Grove, Indiana
Background: The study was designed to quantitate factors such as preparation time, waste, and contamination associated with three different feeding systems for peptide-based diets, and to determine appropriate hang times. Methods: Intensive care unit patients were randomized to receive a peptide-based diet in 1500-mL prefilled, sterile closed-system containers (CS) infused more than 24 hours, as open systems decanted from cans (OS-Can), or as open systems mixed from powder (OS-Powder). Open-system groups were provided a 12-hour supply twice daily in commercially clean 1-L bags with preattached sets. Samples were taken for culture during preparation and after infusion. Preparation time, initial and final microbial concentrations, and total waste were quantified. Results: Preparation time was significantly shorter for CS than for OS-Can or for OS-Powder (2 minutes vs 7.5 minutes vs 13.0 minutes). Initially, 100% of the OS-Powder and 30% of the OS-Can bags were contaminated, with significant contamination exceeding 104 colony-forming units/mL in 40% and in 5% of the bags, respectively. On final culture, significant contamination occurred in only 2% of the CS bags compared with 83% of the OS-Powder and 60% of the OS-Can bags. Average time from potential initial contamination to final culture in CS was 49.9 hours vs 38.8 hours for OS-Can and 32 hours for OS-Powder. Total waste was greater in CS than in OS-Can or OS-Powder but could be eliminated by extending allowable hang times. Conclusions: Nonvented closed-delivery containers may be safely infused for up to 48 hours. They are associated with reduced labor and contamination. (Journal of Parenteral and Enteral Nutrition 18:453-457, 1994)