Measuring environmental contamination in critical care using dilute hydrogen peroxide (DHP) technology: An observational cross-over study

Background: The environment has an important role in the transmission of healthcare associated infections. This has encouraged interest in novel methods to improve hygiene in hospitals. One such technology is the use of hydrogen peroxide to decontaminate rooms and equipment; there are, however, few studies that have investigated the effect of continuous dilute hydrogen peroxide (DHP) in the clinical environment. The aim of this study was to examine the use of dilute hydrogen peroxide (DHP) in a critical care unit and measure the microbiological impact on surface contamination.

Methods: We conducted a prospective observational cross-over study in a ten-bed critical care unit in one rural Australian hospital. Selected high-touch sites were screened using dipslides across three study phases: baseline; continuous DHP; and no DHP (control). Quantitative aerobic colony counts (ACC) were assessed against a benchmark standard of ACC >2.5 cfu/cm² to indicate hygiene failure.

Results: There were low levels of microbial contamination in the unit for baseline; DHP; and no DHP phases: 2.2% (95% CI 0.7-5.4%) vs 7.7% (95% CI 4.3-13.0%) vs 6% (95% CI 3.2-10.4%) hygiene failures, respectively. Significant reduction in ACCs did not occur when the DHP was operating compared with baseline and control phases.

Conclusion: Further work is needed to determine whether continuous DHP technology has a role in decontamination for healthcare settings.