Trauma ICU patients are similar to mixed ICU patients with respect to risk factors for developing VAP, unlike patients undergoing elective cardiac surgery. Use of 0.12% chlorhexidine digluconate decreases the incidence of VAP in patients undergoing elective cardiac surgery. In mixed ICU patients, chlorhexidine digluconate at concentrations less than 0.2% has consistently been shown to have no benefit [2]. A randomized trial using 2%  chlorhexidine digluconate has, however, demonstrated a reduction in VAP rates in these patients [3]. A previous study showed that 12-hourly application of chlorhexidine digluconate  has a sustained preventive effect on biofilm formation [4]. The lack of benefit from twice-daily oral cleansing with chlorhexidine digluconate in the present study may be due to the lower concentration of chlorhexidine digluconate .The authors' recommendation for investigation into mechanical plaque removal withchlorhexidine digluconate would conceptually have some added benefit. Mechanical plaque removal withchlorhexidine digluconate, however, has not affected outcomes in ICU patients in two studies [5,6].We therefore suggest that further studies using oral chlorhexidine digluconate  in ICU patients should be conducted using higher concentrations (2%) to test the most appropriate frequency of use, since oral cleansing is a nursing-driven intervention and clinical trials with chlorhexidine digluconate are yet to demonstrate a mortality benefit.ICU: intensive care unit; VAP: ventilator-associated pneumonia.The authors declare that they have no competing interests.