An updated systematic review and meta-analysis evaluated whether daily bathing with 2% chlorhexidine gluconate (CHG) improves key clinical outcomes in critically ill patients compared with traditional soap-and-water (SAW) bathing. While CHG has recognised antimicrobial properties and has been widely studied for infection prevention, its broader impact on outcomes such as mortality, illness severity, and ICU length of stay remains uncertain.
Previous research has largely focused on infection-related endpoints, particularly bloodstream infections linked to invasive devices, with inconsistent findings. Although reducing infections could theoretically improve survival and reduce illness severity, meta-analyses to date have not demonstrated clear benefits in mortality or ICU stay. Earlier studies often included heterogeneous protocols (e.g. varying bathing frequency or comparators), limiting comparability.
This review provides a more methodologically consistent analysis by including only studies comparing daily 2% CHG bathing directly with SAW. The included studies consisted of three cluster randomised trials and seven non-randomised studies conducted across multiple countries and ICU settings.
For mortality, eight studies including 17,793 patients were analysed. The pooled estimate suggested a borderline reduction in risk of death with CHG bathing (RR 0.93), but this did not reach clear statistical significance and was supported by very low certainty evidence.
Heterogeneity was low, indicating consistent findings across studies, yet prediction intervals suggested that future studies could show either a small benefit or no effect. Sensitivity analyses confirmed that results were not robust enough to establish a definitive mortality benefit.
Clinical severity, assessed using APACHE scores, was analysed in six studies involving 9,957 patients. No significant difference was observed between CHG and SAW groups, with extremely high heterogeneity. This variability likely reflects differences in patient populations, timing of measurement, and ICU characteristics. Even after sensitivity analyses, results remained inconsistent, and any observed effects were driven largely by individual studies. The certainty of evidence was therefore rated as very low, and no reliable conclusion could be drawn regarding the impact of CHG bathing on overall illness severity.
ICU length of stay was evaluated in seven studies (11,123 patients). The meta-analysis found a statistically significant but clinically negligible increase in length of stay among patients receiving CHG bathing. This effect was heavily influenced by a single large observational study contributing the majority of statistical weight. Randomised trials did not show a significant difference, and sensitivity analyses removing high-risk studies eliminated the observed effect. Overall, the evidence was considered low certainty and insufficient to support a meaningful association.
The discussion emphasises that although CHG bathing may reduce healthcare-associated infections, this does not necessarily translate into improved survival or reduced severity. Mortality in critically ill patients is multifactorial, driven primarily by baseline illness severity, comorbidities, and treatment factors rather than isolated preventive interventions. Similarly, severity scores are dynamic and influenced by numerous variables, limiting their comparability across studies. The minimal and inconsistent findings for ICU length of stay further highlight the complexity of linking infection prevention strategies to broader clinical outcomes.
Source: European Journal of Clinical Microbiology & Infectious Diseases
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