The effects of rinsing enteral delivery sets on formula contamination

This study investigated whether rinsing enteral delivery sets before formula addition affects formula contamination. Both a simulated and a clinical phase were conducted. In the simulated phase, Osmolite (Ross Laboratories, Columbus, OH) was infused continuously through 52 delivery sets into a flask via enteral infusion pumps for 24 hours. The delivery sets were randomly assigned to two groups of equal size. One group was rinsed with tap water before new formula was added at 8 and 16 hours, and the other group was not rinsed. At 8, 16, and 24 hours, samples of formula were collected from the delivery sets, and bacteria counts were obtained. In the clinical phase, 23 critically ill patients receiving Osmolite continuously were randomly assigned to a rinse or no-rinse group. The same formula addition and rinse protocol from phase I was used. Formula samples were obtained at 24 hours. In both phases, there were no significant differences between the rinse and no-rinse groups with respect to bacteria counts at any time period. The findings suggest that rinsing may be unnecessary if delivery sets are used continuously for 24 hours or less; however, the possibility of a type II error because of the small sample size of this study must be recognized.