Background: There are clinically relevant discrepancies between prescribed volumes and delivered volumes of enteral nutrition (EN) in intensive care unit (ICU) patients. Next to EN-protocol violations due to insufficient care, we hypothesized technical factors to be responsible for this deficit. The aim of this study was to determine the accuracy of EN feeding pump systems frequently used in the ICU.
Methods: Thirteen commercially available EN feeding pumps with their own delivery systems were tested in 12 sessions with different EN feeding tubes and EN formulas in a laboratory setting. The reproducibility of the measurements was determined for the 8 best performing EN feeding pump systems.
Results: There were clinically important differences between prescribed volumes and delivered volumes of EN in the tested EN feeding pump systems. The deficit in volume ranged from +66 mL (surplus of 66 mL) to -271 mL (deficit of 271 mL) per 24 hours (14% of prescribed volume). Viscosity of test fluids (water/EN feeding formulas) and resistance of test tubes had no influence on the delivered volume by the tested EN feeding pump systems, because differences between prescribed volumes and delivered volumes were consistently found for each system while varying these test settings.
Conclusions: Differences between prescribed and delivered EN volumes are caused by the function and construction of EN feeding pump systems. To improve nutrition therapy, the flow rate has to be adjusted or the best-performing EN feeding pump has to be purchased.