Accuracy of water delivery in enteral nutrition pumps

Background: Adequate delivery of both enteral formula and water in patients receiving enteral nutrition (EN) is critical in illness recovery and maintaining hydration status. Pump malfunction has recently been identified as a factor that impedes enteral formula delivery, however rarely is inadequate enteral water delivery investigated. The purpose of this study was to explore the accuracy of delivering 1 L of water by EN pumps using different flush volumes and hang heights. Methods: Three EN pumps were used in vitro to flush 1 L of water at 50 mL per hour for 20 hours and 500 mL every 4 hours for 8 hours, at 0” and 18” hang heights. Fifteen test runs were conducted at each volume and hang height per pump. Actual delivered enteral water, remaining volume in feed bags, and volume reported by the pump were recorded. Results: Hang height of 18” delivered a mean 3.91% (95% CI, 3.25 to 4.57) more water than bags hung at 0” (p < 0.0005). When delivering water in 500 mL increments, 1.57% (95% CI, 0.92 to 2.23) more water was delivered than when delivered in 50 mL increments (p < 0.005). Conclusion: Appropriate hang height recommendations improve enteral water delivery in patients receiving EN. The most accurate setting was 500 mL at 18”, resulting in adequate delivery in 97.8% of the test runs, while 50 mL at 0” delivered adequately 17.8% of the time. More research is needed to understand the implications of inadequate water delivery caused by EN pump inaccuracy.