Clinical Research: Microbial Contamination of Low-Profile Balloon Gastrostomy Extension Tubes and Three Cleaning Methods

Abstract

It is common practice to wash and reuse low-profile gastrostomy (LPG) extension tubes for several weeks or as long as the tubes remain functional. This laboratory study investigated three different cleaning methods and their effectiveness for lowering the microbial contamination of extension tubes challenged with Staphylococcus epidermidis, Enterobacter aerogenes, Candida albicans, and Acinetobacter. The Food and Drug Administration (FDA) limit of an aerobic plate count exceeding 10,000 (10⁴) organisms per gram of product for microbial contamination of enteral formulas was used as the standard. One hundred thirty-two extension tubes were used (66 analyzed at 8 days and the remaining 66 analyzed at 18 days), 30 per each inoculated group and 12 with uninoculated formula. Each group was divided into three subgroups for cleaning methods: (1) tap water flush and air drying; (2) warm, soapy water flush followed by a tap water flush and air drying; and (3) warm, soapy water flush followed by a tap water flush and then a final flush with 30 mL of a quaternary ammonium sanitizer at a concentration of 200 parts per million (ppm) and air drying. The medication port was not flushed and the tube was not soaked in the quaternary ammonium sanitizer. A modified version of method 3 was used on days 14 to 17 of the study after day 8 results were obtained. In this method, after the final sanitizer flush, the Y-ports were manually agitated in the sanitizer solution for 15 seconds and the tubes were then fully immersed in the solution for 2 minutes. The first two cleaning methods, ie, tap water flush and soap and water flush followed by a tap water flush, were not found to be effective in reducing bacteria and yeast contamination ≤10,000 (10⁴) colony-forming units (CFU) per sample at 18 days. The third cleaning method, which included flushing with soap, tap water, and a quaternary ammonium sanitizer, manual agitation for 15 seconds and immersion in sanitizer for 2 minutes, was found to be effective in reducing bacterial and yeast contamination to ≤2.4 X 10³. The findings suggest that the common practice of washing the extension tube in soapy water, rinsing, and air drying is ineffective for reducing the microbial count to ≤10,000 (10⁴). However, adding a quaternary ammonium sanitizer flush, agitation, and 2-minute soak to the cleaning regimen reduced the microbial count to acceptable levels at 18 days, suggesting that the LPG extension tubes can potentially be used safely for at least 2 weeks if this protocol is followed.