Comparison of the efficacy of soaking and drying methods for the disinfection of handwashing sinks in ICU

Jieqiong ChenYu ChenXiaomin XuChenxi Tong^*Zhaojun Xu^*

• Ningbo Second Hospital, Ningbo, China

Objective: This study aimed to investigate the effects of drying, soaking, and two combined disinfection methods on the disinfection efficiency of ICU handwashing sinks. Methods: From January to June 2024, eight handwashing sinks in the ICU were randomly divided into control group (n=2), soaking group (n=2), drying group (n=2), and combination group (n=2). The control group wiped with quaternary ammonium wipes only; the soaking group used chlorine disinfectant for 30 minutes based on the control group; the drying group was dried in a dryer for 15 minutes based on the control group; and the combined group was a combination of soaking and drying. Samples were collected once a month to compare the ATP fluorescence values and bacterial detection rates. Fisher's exact test was used to compare categorical variables, Kruskal-Wallis's test was used to compare continuous variables. Dunn's post-test was used for pairwise comparison between groups.The study found that before disinfection, no significant differences in ATP levels were observed among the four groups (P = 0.615). After disinfection, significant differences emerged (P < 0.001, η² = 0.225), with the combined group showing the lowest ATP values and highest pass rate (100%). Dunn's post hoc tests revealed the combined group had significantly lower ATP values compared to other groups (P < 0.01, Cohen's d > 1.369). Bacterial detection showed an overall rate of 22.92% (11/48), with Pseudomonas aeruginosa being the predominant pathogen (81.82%, 9/11). The combined group had no bacterial isolates, while other groups had varying levels of contamination. Conclusion: Overall, all four methods in this study were found to be effective in disinfecting ICU handwashing sinks, but the combined method of soaking and drying was superior to the other three.