Participants and setting
The setting was a 22 bed combined general intensive care and high dependency unit within an 800 bed district general hospital in northern England. In the 30 months of the project (July 2009 to December 2011) 2659 patients were admitted
to the unit. 1087 patients were mechanically ventilated for at least 48 hours; 528 in 15 months prior to the change in oral care and 559 patients after the change. All patients who were mechanically ventilated for at least 48 hours were included in the project except one patient in the post change group who had experienced a previous anaphylactic reaction to chlorhexidine. Known chlorhexidine allergy was the single exclusion criteria for the study since it precluded compliance
with the oral care regimen. The age, gender and medical or surgical speciality of the patients did not differ significantly (see Table 3).