Decontamination strategies to remove potentially harmful bacteria from the mouth, throat and gut of critically ill patients don’t reduce the risk of intensive care unit-acquired bloodstream infections or deaths from bacteria that were resistant to antibiotics. The study was carried out in 13 intensive care units across Europe, including the UK, with moderate to high levels of antibiotic resistance (extended resistance in more than 5% of all bloodstream infections). This fills an important gap in the evidence as most previous studies have been in units with lower levels of resistant organisms.

Infections with multi-drug resistant gram-negative bacteria are a frequent problem for ventilated patients on intensive care wards. In this trial of 8,665 patients, the use of chlorhexidine mouthwash, selective digestive tract decontamination, or selective mouth and throat decontamination were compared to standard care, involving daily body washings with chlorhexidine and a hand hygiene improvement programme.

The decontamination strategies were not associated with a significant difference in multi-drug resistant bloodstream infections, suggesting that they should not be used in the UK as a strategy to reduce antibiotic resistance in hospitals with similar extended resistance rates.