This Cochrane Systematic Review by Lewis and colleagues was first published online in August 2019.
What is the aim of this review?
The aim of this review was to find out whether people who are critically ill in hospital should be bathed with the antiseptic chlorhexidine, in order to prevent them from developing infections. Researchers from Cochrane collected and analysed all relevant studies to answer this question and found eight relevant randomised trials. Randomised trials are medical studies where people are chosen at random to receive different treatments. This study design provides the most reliable evidence on whether treatments have a relationship with desired or undesired health outcomes.
This review assesses whether using chlorhexidine (instead of soap and water) to bathe patients in an intensive care unit (ICU), or a high‐dependency or critical care unit reduces the number of hospital‐acquired infections. The evidence available from the studies we analysed was very low quality, meaning that we cannot be certain whether bathing with chlorhexidine reduces the likelihood of critically‐ill patients developing an infection, or dying. We are also uncertain whether bathing critically ill patients with chlorhexidine shortens the length of time people spend in hospital, or lowers their risk of developing skin reactions.
What was studied in the review?
People who are critically ill (in an ICU, or a high‐dependency or critical care unit) often catch infections during their time in hospital. These infections can lead to longer hospital stays, additional medical complications, permanent disability or even death. Patients in ICUs are particularly vulnerable to infections because the body’s ability to fight infection is reduced by illness or trauma. Surgical tubes and lines (for example to help with feeding or breathing) may enable bacteria to enter the body. Chlorhexidine is a low‐cost product which is used as an antiseptic and disinfectant in hospitals.
What are the main results of the review?
In December 2018 we searched for studies looking at the use of chlorhexidine for bathing critically ill patients. We found eight studies dating from 2005 to 2018, involving a total of 24,472 people across more than 20 ICUs. Seven studies included people who were adults, and one study included only children. All studies included both males and females. All studies compared bathing with chlorhexidine versus bathing with soap and water or non‐antimicrobial washcloths. Four studies received funding from independent funders (government organisations, or from hospital or university departments) or reported no external funding, and four studies received funding from companies that manufactured chlorhexidine products.
The evidence from all eight studies combined is not sufficient to allow us to be certain whether patients bathed in chlorhexidine are less likely to catch an infection during their stay in the ICU. We are also uncertain whether patients bathed in chlorhexidine are less likely to die, because the certainty of the evidence from the six studies that reported on this is very low. We did not pool the evidence from the six studies that reported how long patients had stayed in the ICU, because the results differed widely. We are also uncertain whether patients bathed in chlorhexidine are likely to be in the ICU for less time, because the certainty of the evidence is very low. Reports from five studies provided different evidence about whether chlorhexidine led to more or less skin reactions; we are uncertain whether patients bathed in chlorhexidine are likely to have more or less skin reactions, because the certainty of the evidence is very low.
How up to date is this review and Quality of evidence
We searched for studies that had been published up to December 2018. Most studies did not use methods to conceal the type of bathing solution that staff were using, which increases the risk that staff may have treated patients differently depending on whether patients were in the chlorhexidine study group or the soap‐and‐water study group. Participants in some studies may have already caught an infection before the start of the study and we were concerned that this might have affected our results. We also noticed wide differences in some results, and some outcomes had few reported events. These were reasons to judge the quality of the evidence to be very low.
Implications for practice
It is not clear whether bathing with chlorhexidine reduces hospital‐acquired infections, mortality or length of stay in the intensive care unit, or whether chlorhexidine use results in more skin reactions, because the certainty of the evidence is very low. One study is awaiting classification and two studies are ongoing; we do not know if inclusion of these studies in future updates of this Cochrane Review will increase our certainty in the results of the review.
Implications for research
Additional research is needed to evaluate whether chlorhexidine bathing may reduce hospital‐acquired infections in the intensive care unit. We recommend that studies are sufficiently powered and methodologically robust, and that attention is paid to reduce the risk of performance bias through blinding of personnel. Cluster‐randomised studies and cross‐over trials would benefit from reporting data in more detail, including important parameters such as the intracluster correlation coefficient and interperiod correlation. Some consensus on the reporting of hospital‐acquired infection rates, for example through the adoption of a core outcome set for trials of infection prevention, would also be helpful.