Accuracy of Enteral Pumps: In Vitro Performance

There are few data on the accuracy of pumps used to deliver enteral formulas. Enteral pump manufacturers claim that accuracy is within 10% of the selected flow rate. We evaluated 15 pumps: Flexiflo Companion (n = 5), Travenol 2100 (n = 5), and Kangaroo 324 (n = 5). Three types of formula at room temperature were infused at 10, 100, and 300 mL/h. The formulas used were Jevity, Ensure Plus, and Suplena with added Promod. The Flexiflo Companion and Kangaroo 324 pumps delivered 90% to 110% of the expected volume using the ready-to-feed formulas. The Travenol 2100 pumps averaged less than 90% of the selected flow rates for the three formulas infused. All three pumps delivered less than 90% of the expected volume using a formula with an added powder, but the Travenol 2100 delivered the highest volume of this same formula. There was no significant difference in the delivery of Jevity with the Flexiflo Companion (104% ± 5% SD) and the Kangaroo 324 pumps (99% ± 4% SD), but the flow rate was significantly lower with the Travenol 2100 pumps (80% ± 6% SD). There was no significant difference in the flow rate of Ensure Plus with the Kangaroo 324 (95% ± 7% SD) and the Travenol 2100 pumps (89% ± 4% SD).The flow rate of Ensure Plus with the Flexiflo Companion pumps was significantly higher (107% ± 4% SD). There was no significant difference in the flow rate of Suplena with Promod using the Kangaroo 324 (80% ± 16% SD) and the Travenol 2100 pumps (87% ± 6% SD), but the flow rate of this same formula mixture was significantly lower with the Flexiflo Companion pumps (53% ± 13% SD). We conclude that enteral feeding solutions are delivered with variable accuracy depending on the enteral pump and formula selection. This study shows that there is no one enteral pump that will serve all enteral formula delivery needs. The addition of a powdered protein module to a ready-to-feed formula significantly reduces the expected flow rate. Frequent monitoring of the amount of enteral formula infused is recommended so that adjustments can be made to ensure that nutritional goals are met. We believe that institutions using enteral pumps should evaluate the accuracy of the pumps used for their formula selections. Industry recommendations concerning the use of powdered formulas should be heeded, and we caution against adding powdered nutrient modules to viscous ready-to-feed formulas. (Journal of Parenteral and Enteral Nutrition 18:359–361, 1994)