Bacterial contamination of enteral feeding systems due to faulty handling procedures—a comparison of a new system with two established systems

Abstract

Background: The purpose of this study was to compare the risks of introducing microbial contamination when assembling and running two commonly used, ready‐to‐hang, enteral feeding systems (Nutrison glass bottles and Steriflo) with a newly introduced system (Nutrison pack). Methods: The nutrient container tops of all systems were deliberately touched during assembly by a researcher wearing gloves contaminated with Klebsiella aerogenes. After touching, half the containers were immediately connected to giving sets, the other half were disinfected using alcohol wipes before connection to the giving sets. Systems were run for 24 h, with a change of nutrient container at 12 h for the Steriflo (2×1000 ml), Nutrison pack (2×1000 ml) and Nutrison glass bottles (2×500 ml), and at 6 h for the Nutrison glass bottles (4×500 ml). Feed samples for microbiological analysis were taken from feed in the systems at the 0 h assembly, and from residual feed in all discarded nutrient containers. Each protocol was repeated five times. Results: The percentage of feed samples in which K. aerogenes was detected reduced significantly from 68% for non‐disinfected Nutrison glass bottles changed every 6 h, to 59% after disinfection, and from 51% to 0% after disinfection of Steriflo systems (Mann–Whitney, P< 0.05). For Nutrison glass bottles changed every 12 h the fall from 51% with no disinfection to 49% after disinfection was not significant (Mann–Whitney, P< 0.05). Nutrison packs were not disinfected and yet K. aerogenes was only detected in 2% of feed samples. This rate of contamination was significantly less than that for all the other non‐disinfected systems (Mann–Whitney, P< 0.05). Conclusion: The results show a reduction in the incidence of bacterial contamination of the feed samples when systems were disinfected subsequent to being exposed to faulty handling procedures, thus supporting manufacturers recommendations to disinfect systems during assembly. The results particularly highlight the important role played by system design in reducing the levels and incidence of bacterial contamination of enteral tube feeds.

Enteral Feeding Set Handling Techniques

“…The overall low growth seen in this study was much less than we premised given the increased manipulation of the EFS. This study design emulated a previous report by Beattie and Anderton 5 in 1998 where enteral feeding systems using both RTH and decanted formula were infused into a beaker with the tip of the EFS suspended above the fluid level to assess the impact of handling on bacterial growth. Investigators deliberately contaminated the hands of those who set up the initial EFS to determine the impact of bacterial contamination over time.…”

“…Overall contamination rates of enteral formulas or the EFS are reported to be between 19% and 59% 3 , 4 , 5 – 8 . Sources of contamination have been identified to originate from any point in preparation to administration of formula.…”

“…Sources of contamination have been identified to originate from any point in preparation to administration of formula. Touch contamination by nursing staff remains a predominant factor in bacterial contamination of enteral formula and is attributed to direct manipulation of the EFS 5 , 6 , 8 . Studies have documented the benefits of good hand hygiene, wearing gloves when accessing the EFS, and the use of ready‐to‐hang (RTH) formula where possible 6 , 8 , 9 .…”

Effect of an infection control programme on bacterial contamination of enteral feed in nursing homes

“…8 Inadequate knowledge about enteral feeding (EF) among healthcare workers (HCWs) may lead to bacterial contamination of EF systems as a result of incorrect handling procedures. 9 Studies have shown that the major source of transmission of pathogens between patients is from contaminated hands of HCWs to clean environmental or skin sites, 10e13 and that areas such as flow regulators are contaminated by HCWs' hands. 8 Other sources of enteral feed contamination include inadequately cleaned equipment and poor kitchen/nursing home environment.…”

Decanting versus sterile pre-filled nutrient containers ‐ the microbiological risks in enteral feeding

“…A study carried out by Schreiner et al (1979) on decanting feeds for neonates and one carried out by Patchell et al (1994) on feeds intended for infants receiving enteral nutrition in hospital or at home have also demonstrated bacteria gaining entry to systems via this route. Assembly and manipulation of feeding systems have also been shown as procedures which can introduce bacteria into the systems (Schroeder et al 1983, Crocher et al 1986, Anderton and Aidoo 1988, Beattie and Anderton 1998, 1999 However, in a follow-up to their earlier study, Patchell et al (1998) demonstrated that staff education and modification of the enteral feeding protocol reduced both the levels and incidence of bacterial contamination. Also, studies by Anderton (1998, 1999) highlighted the important role played by system design in reducing the number of bacteria introduced into feeds during the assembly of systems and the delivery of the feed.…”