This was a single-centered, randomized, placebo-controlled double-blind clinical trial conducted in the pediatric intensive care unit (PICU), in patients who were aged 1 month to 18 years, needing MV for at least 48 hours, to evaluate the effect of Chlorhexidine (CHX) on Ventilator-associated pneumonia (VAP) incidence and to determine VAP risk factors.

Patients were randomized into two groups receiving CHX (0.12%) or placebo (0.9% NaCl) and followed for VAP development. All patients were consecutively randomized (1:1) to receive either 0.12% CHX rinse solution or placebo applications using a computer generated balanced randomization table. The unlabeled standardized tubes containing placebo or 0.12% CHX were serially numbered and bagged for each patient according to randomization. The preparation of bagged treatments and their numbering were done by the same personnel who was not involved in the study. The placebo rinse contained 0.9% NaCl (normal saline [NS]), and was identical to the 0.12% CHX rinse solution with regard to appearance, consistency, taste and smell. The patients, physicians, outcome assessors, and data analysts were kept blinded to the intervention.

The standard care protocols in the PICU were performed. Before beginning the study, nurses received a training program for VAP prevention, procedure/technique for oral hygiene and use of oral mucosa assessment score under supervision of pediatric residents. They were trained on the method of application of solutions according to CDC guidelines in order to ensure uniform treatments. Nurses were double blinded and had no knowledge of the solution they were using.

Both treatment groups (placebo and 0.12% CHX) received treatments at 4-hour intervals, nurses used the whole content of 5 ml tubes containing rinse solution. In both groups, nurses performed oral cleansing as follows: first, the endotracheal cuff pressure was tested to ensure proper pressure prior to oral care and oropharyngeal secretions were aspirated to remove any accumulated secretions. Then the application of rinse solutions to cleanse all areas of the oral cavity, including the anterior and posterior pharynx, gums, teeth, tongue, and buccal mucosa, with standard disposable applicator (foam swab) was applied, followed by removal of excess solution from the mouth by a sterile catheter. Strict hand hygiene was ensured during the procedures. The period of application was from the day of intubation until extubation. Presence of any adverse effect of the solutions was recorded. Beck oral assessment score (BOAS) was used twice daily to evaluate the oral health of both groups.

Inclusion Criteria:

• aged 1 month to 18 years
• needing MV for at least 48 hours
• PICU patients

Exclusion Criteria:

• not consenting to participate in the study
• known hypersensitivity to CHX
• presence of tracheotomy,
• undergoing MV for less than 48 hours
• having received MV for more than 24 hours prior to PICU admission
• readmission to PICU
• suspected or diagnosed immunodeficiency
• history of malignant disease(active or at remission),
• being diagnosed with oral mucositis or periodontal disease
• chronic pulmonary and/or cardiac diseases
• having severe oral/facial trauma,
• use of immunosuppressive drugs (such as corticosteroids).