Decontamination Strategies Ineffective against ICU Bloodstream Infections

Neither prophylactic antibiotics nor antiseptic mouthwash significantly reduce multidrug-resistant gram-negative bloodstream infections in ventilated intensive care unit (ICU) patients, claims a new study.

Researchers at University Medical Center Utrecht (UMCU; The Netherlands), Henri Mondor University Hospital (CHU Mondor; Créteil Cede, France), Centre Hospitalier Universitaire de Liège (CHU Liege; Belgium), and ten other European ICUs conducted a randomized study to determine associations between chlorhexidine (CHX) mouthwash, selective oropharyngeal decontamination (SOD), and selective digestive tract decontamination (SDD) on the occurrence of ICU-acquired bloodstream infections.

The study was conducted from December 1, 2013 to May 31, 2017, in ICUs where at least five percent of bloodstream infections are caused by extended-spectrum β-lactamase–producing Enterobacteria. In all, 8,665 patients (median age 64.1 years; 64.2% men) with anticipated mechanical ventilation of more than 24 hours were eligible. Each ICU was randomly assigned to a six-month intervention with either CHX 2% mouthwash, a SOD mouthpaste with colistin, tobramycin, and nystatin, or an SDD with the same antibiotics, all applied four times daily to patients who were ventilated for at least 24 hours.

The results revealed that 144 of the patients experienced an ICU-acquired bloodstream infection with multidrug-resistant gram-negative bacteria (MDRGNB); 2.1% of infections occurred during the baseline period; 1.8% during CHX; 1.59% with SOD; and 1.2% with SDD. Compared with baseline, absolute risk reductions were 0.3%, 0.6%, and 0.8%, respectively. Crude morality risks on day 28 were 31.9% during baseline, 32.9% with CHX, 32.4% with SOD, and 34.1% with SDD. The study was published on October 22, 2018, in JAMA.

“In addition to lack of efficacy against bloodstream infections, there is no beneficial effect on survival of ICU patients, which is in contrast with previous studies performed in settings with lower levels of antibiotic resistance,” said lead author Bastiaan Wittekamp, MD, of UMCU. “The indication that there may be differences in the effectiveness of decontamination strategies that may depend on the level of antibiotic resistance warrants further investigations.”

Infections acquired in the ICU are important complications of the treatment of critically ill patients, increasing morbidity, mortality, and health care costs. Reductions in the incidence of respiratory tract infections have been reported using prophylactic antibiotic regimens, such as SDD and SOD. Due to concerns about increased selection of antibiotic-resistant pathogens, the routine use of SDD and SOD has remained controversial, and has not been recommended in international guidelines.

Related Links:
University Medical Center Utrecht
Henri Mondor University Hospital
Centre Hospitalier Universitaire de Liège