Decontaminants Don't Cut Bloodstream Infection Risk in Ventilated ICU Patients

The use of digestive and oral decontaminants in patients in the intensive care unit (ICU) who are mechanically ventilated and who have moderate to high antibiotic resistance is not associated with a reduction in ICU-acquired bloodstream infections caused by multidrug-resistant gram-negative bacteria.

According to the results of a randomized clinical trial conducted by investigators in the Netherlands and published in the Journal of the American Medical Association (JAMA), when compared with standard care, the use of chlorhexidine (CHX) 1% mouthwash, selective oropharyngeal decontamination (SOD), and selective digestive tract decontamination (SDD) made no discernible difference in whether patients developed bloodstream infections from multidrug-resistant gram-negative bacteria.

The baseline standard care routine involved chlorhexidine body washing and a hand hygiene improvement program, the authors noted.

The investigators analyzed data from 13 European ICUs where a total of 8665 patients with moderate to high antibiotic resistance had been on mechanical ventilation for at least 24 hours.

Following a baseline care period of 6 to 14 months, each decontaminant was administered four times daily for a six-month period.

A total of 144 patients contracted ICU-acquired bloodstream infections with multidrug-resistant gram-negative bacteria. The infections occurred in 2.1%, 1.8%, 1.5%, and 1.2% of included patients during the baseline, CHX, SOD, and SDD periods, respectively.

Absolute risk reductions were 0.3% (95% CI, −0.6% to 1.1%), 0.6% (95% CI, −0.2% to 1.4%), and 0.8% (95% CI, 0.1% to 1.6%) for CHX, SOD, and SDD, respectively, compared with baseline. Crude mortality risks on day 28 were 31.9%, 32.9%, 32.4%, and 34.1% during the baseline, CHX, SOD, and SDD periods, respectively.

“[Selective decontamination of the digestive tract (SDD)] and [selective oropharyngeal decontamination (SOD)] are routinely used in ICUs in the Netherlands, but their use has not been widely adopted in other countries, mainly because of limited efficacy data in settings with higher levels of antibiotic resistance and concern about emergence of antibiotic resistance, although the latter is not supported by meta-analyses,” Bastiaan H. Wittekamp, MD, PhD, of University Medical Center Utrecht in the Netherlands, and colleagues wrote in JAMA.

The study authors noted 2 deviations from study procedures that may have impacted outcome.

“The study was temporarily interrupted in 2 centers. In 1 center, an increased prevalence of colistin-resistant Klebsiella pneumoniae was identified by the safety committee, which led to the identification of a clonal outbreak after SOD had been used for 3.5 months. After a 7-month period of outbreak containment, SOD was reintroduced. In another center, the hospital infection control committee interrupted the study after SOD had been used for 5 months, pending evaluations of an increased prevalence of carbapenem-resistant Enterobacteriaceae. Further investigation revealed that the outbreak was polyclonal and occurring in multiple hospital wards simultaneously.”

The median age of study participants was 64.1 years and 64.2% of them were men.

“The study by Wittekamp and colleagues in this issue of JAMA evaluating strategies for decontamination of mechanically ventilated patients in the intensive care unit (ICU) fills an important gap in the evidence regarding these practices,” Christina MJE Vandenbroucke-Grauls, MD, PhD, of Amsterdam University Medical Center, and Jos W.M. van der Meer, MD, PhD, of Radboud University Medical Center in the Netherlands, commented in an accompanying editorial.

“[The study] shows no benefits in situations with higher antibiotic resistance patterns that unfortunately still prevail in most ICUs around the world.”