435 - Shake it up: intermittent agitation improves fat delivery of donor human milk during bolus and continuous feeds

Poster Number: 435
Publication Number: 435.302

Caitlin Irwin, Indiana University School of Medicine, Avon, IN, United States; Kate Beard, Riley Hospital for Children at Indiana University Health, Indianapolis, IN, United States; Wendy Cruse, Riley Hospital for Children at Indiana University Health, Indianapolis, IN, United States; Kok Lim Kua, Indiana University School of Medicine, Indianapolis, IN, United States; Katie Huff, Indiana University School of Medicine, Indianapolis, IN, United States

Background: Human milk is widely recognized as the gold standard of nutrition in the NICU and is often delivered via a feeding pump. A known challenge of feeding pumps is reduced fat delivery to the neonate. Clinical practice that improves fat delivery is important to improve caloric intake and potentially the growth of infants. However, studies have not thoroughly investigated the role of manual agitation in improving human milk fat delivery during different feeding rates on a bottle-pump system.

Objective: We hypothesize that intermittent manual mixing of donor human milk (DHM) during enteral feeds with a bottle-pump system decreases the gravitational separation of milk and results in improved fat retention during bolus and continuous feeds.

Design/Methods: We performed an in-vitro study to simulate the nutritional intake of an 850g infant at 150 mL/kg/d. Samples of 16mL DHM were delivered via a bottle-feeding pump system over 15 min, 60 min, 90 min and over 4 hour continuous rates. For 60 min, 90 min and continuous feed rates, simulations were repeated with manual mixing of milk bottle (inverting bottle 10 times) at 30min intervals. The DHM macronutrient and caloric content were measured using FDA-approved Human Milk Analyzer (MIRIS AB, Uppsala, Sweden) prior to infusion as baseline and immediately after completion of each simulation. Percent changes of macronutrients and calories of baseline were calculated and statistical differences were determined using one-way ANOVA followed by Bonferroni post hoc analysis. Simulations were tested 9 times at each rate using 9 different batches of DHM milk.

Results: There was no difference in DHM macronutrient content when delivered over 15 min. Fat and caloric content of DHM were significantly reduced during 60 min (fat 60.3±1.8%; calorie 79±1% of baseline), 90 min (fat 57.8±6.1%; calorie 77.8±3.5% of baseline), and continuous feeding rate (fat 42.2±1.4%; calorie 70.9±0.5% of baseline). Manual mixing significantly improved fat delivery compared to that of non-mixed milk in bolus and continuous feeds. Fat retention improved from 60.3% to 77.6% (p-value = 0.01) with mixing for feeds over 60 min, from 57.8% to 85.5% (p-value < 0.01) for feeds over 90 min and from 42.2% to 69.9% (p-value < 0.01) during continuous feeds.Conclusion(s): Enteral feeding pumps utilizing a bottle result in significant loss of fat delivery. Our results suggest intermittent mixing of milk leads to improved fat retention likely due to decreased gravitational separation of fat in milk. A simple way to improve fat delivery to the neonate is to manually mix the bottle of milk during feeds.