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

Abstract

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)