Enteral feeding contamination: comparison of diluents and feeding bag usage

This quasi-experimental study compared bacterial growth in enteral feeding solution in six Kangaroo feeding bags filled with enteral formula diluted with sterile water vs six of the same diluted with tap water. Feeding bags, which were on continuous pumps in patient-occupied rooms, were rinsed and refilled every 8 hours, and formula cultures were obtained at 0, 24, and 48 hr. Acceptability of cultures was based on published recommended standards. Low levels of nonpathogenic staphylococci were found in sterile water bags; high levels of bacilli and Gram negative rods were found in tap water bags. No significant differences were found in the relationship between type of formula diluent and outcomes. Type of water diluent and acceptability were not related. There was a systematic relationship between length of use and outcome; with both diluents, bags used over 24 hr became unacceptably contaminated. Further study with a larger sample is needed to determine the effects of using tap water rather than sterile water as diluent.