Preventive strategies in VAP: Focus on silver-coated endotracheal tubes

Introduction: Ventilator-associated pneumonia (VAP) is problematic because of its frequency, morbidity, and mortality. Many strategies have been studied in an attempt to reduce the rate of VAP. This chapter provides a comprehensive review of silver-coated endotracheal tubes in the prevention of VAP. Methods: Two silver-coated endotracheal tubes have been studied in comparison with similar, uncoated tubes-each beginning with preclinical models and progressing to clinical studies. One is commercially available (Agento^® IC, C. R. Bard, Covington, Georgia, United States) and is coated with silver ions micro-dispersed in a proprietary hydrophilic polymer. The other remains investigational and is prepared by submerging a standard endotracheal tube into silver sulfadiazine (with or without chlorhexidine) and polyurethane. Results: Both silver-coated tubes were active in preclinical models designed to mimic surrogate endpoints for VAP, such as in vitro bacterial adherence, biofilm formation, and bacterial burden in animal models. Both tubes were active in phase 2 studies of patients requiring mechanical ventilation. The commercially available tube was active in a randomized, phase 3 study and reduced the incidence of microbiologically confirmed VAP at any time after intubation (silver vs. uncoated, 37/766 [4.8 %] vs. 56/743 [7.5 %]; P = 0.03; relative risk reduction, 35.9 %) and within 10 days of intubation (27/766 [3.5 %] vs. 50/743 [6.7 %]; P = 0.005, relative risk reduction, 47.6 %). Conclusions: The silver-coated endotracheal tube is a promising strategy for preventing VAP. The commercially available tube meets the standards for evidence-based guidelines because effectiveness is supported by the results of a well-designed, phase 3 study. In addition, the device is suitable for use in the intensive care unit because it becomes user independent after intubation and does not add to the burden of busy healthcare providers.