Impact of Three Types of Mouthwash: "Colistin and Chlorhexidine," "Tobramycin and Chlorhexidine," and "Chlorhexidine Alone" in Preventing Ventilator-Associated Pneumonia in ICU Patients: A Randomized Clinical Trial.

Background: Ventilator-associated pneumonia (VAP) is a major cause of infection in patients, and reducing oral cavity contamination can lower mortality rates due to VAP. This study evaluates the effects of the combined administration of three medications, colistin, chlorhexidine, and tobramycin, on the prevention of VAP. Materials and Methods: This double-blind randomized clinical trial was conducted on 96 patients connected to ventilators and admitted to the intensive care unit of Al-Zahra Hospital in Isfahan. The patients were randomly divided into three groups of 32. Over five days, they received "Colistin + Chlorhexidine," "Tobramycin + Chlorhexidine," and "Chlorhexidine-alone" four times daily. The Clinical Pulmonary Infection Score (CPIS), patients' oral hygiene using the Beck Oral Assessment Scale (BOAS), and positive or negative results of oral and tracheal cultures were evaluated before and after the intervention. Results: The results of the present study showed that the CPIS score in the chlorhexidine + colistin group, with the mean of 7.23 ± 1.87, was significantly lower than the chlorhexidine + tobramycin group and the chlorhexidine-alone group, with the means of 12.32 ± 2.67 and 14.05 ± 1.10, respectively (P = .038). Additionally, the BOAS score in the chlorhexidine + colistin group, with the mean of 3.04 ± 1.02, was significantly lower than the chlorhexidine + tobramycin group and the chlorhexidine-alone group, with the means of 6.25 ± 2.00 and 7.06 ± 2.35, respectively (P = .042). Conclusion: Preventive and hygienic oral care is an effective factor in reducing VAP. There was no significant difference among the three treatment combinations in reducing the incidence of VAP. However, it appears that adding colistin may have a slightly better performance in preventing lung infections and inhibiting bacterial agents.