(498) Ventilator-Associated Pneumonia Development Based on Chlorhexidine Exposure After New Tracheostomy

Introduction: Chlorhexidine is commonly used in VAP prevention bundles for chemical decontamination of the oral cavity. There has been ample investigation of chlorhexidine and its benefit in the critically ill requiring mechanical ventilation via an endotracheal tube, but there is a paucity of data for patients with a tracheostomy. This research seeks to assess the development of VAP based on exposure to chlorhexidine in patients requiring a new tracheostomy for mechanical ventilation.

Methods: This single center, retrospective cohort study compared the incidence of VAP based on chlorhexidine exposure. Adult patients admitted between May 7, 2018, and January 1, 2022, to an ICU were reviewed. Patients that received a new tracheostomy for mechanical ventilation and remained on the ventilator for at least 48 hours, without a continuous break of at least 24 hours, were included. Patients who were treated for pneumonia at the time of tracheostomy or did not meet the research criteria were excluded. Group allocation was based on if patients received chlorhexidine within the first 24 hours post-tracheostomy.

Results: Of the 235 patients that were included in this study, 203 received chlorhexidine and 32 did not. The cohort was predominantly white (83.8%), male (56.2%) and admitted to a surgical ICU (59.6%) with a median Charlson Comorbidity Score of 4 (IQR 2,7). Baseline demographics were well balanced between groups. VAP incidence was similar between patients exposed to chlorhexidine and those that were not (33.5% vs. 34.4%, p=0.87). The time to development of VAP was also similar between the two groups (9 days vs. 12 days, p=0.34). A significant threshold of chlorhexidine exposure for prevention of VAP, based on time or administered doses, was not identified in this study.

Conclusions: Chlorhexidine exposure was not found to impact the incidence of VAP after new tracheostomy for mechanical ventilation. Future studies should examine the results of this hypothesis generating study and aim to further elucidate the role of chlorhexidine in VAP prevention post tracheostomy.