Manual Friction with Ethyl Alcohol at 70% (<i>w</i>/<i>v</i>) to Disinfect Three-Way Stopcocks

The disinfection procedures aim to reduce the microbial load, but there are doubts about the risks of contamination spreading into the lumens of devices, such as three-way stopcocks (3-WS). This study aimed at an in vitro evaluation of the antibacterial procedure of manual friction of 3-WS intentionally contaminated and to determine the solution dispersion into the lumens. Laboratory experiments were developed in two steps: evaluation of bacterial spread through intentional contamination with <i>Staphylococcus aureus</i> and <i>Pseudomonas aeruginosa</i>, and alcohol dispersion into the 3-WS lumens. After manual friction of the 3-WS with saline solution at 0.85% (<i>w</i>/<i>v</i>) [control group], <i>S. aureus</i> and <i>P. aeruginosa</i> were isolated in the lumens of 55.6% and 27.8% of the devices, respectively. However, after the disinfection of the 3-WS with ethyl alcohol at 70% (<i>w</i>/<i>v</i>), there was no bacterial contamination in the lumens of the 3-WS. On the other hand, the solution dispersion (dye) into the lumens was evidenced by two different techniques: Durham tubes (5.6%) and swabs (46.3%). The manual friction of the 3-WS with ethyl alcohol at 70% demonstrated antibacterial efficacy, but it refers to reflections on the risk of solution diffusion into the venous network and the inherent clinical practice situations and patient safety.