Objectives: To investigate the effectiveness of mechanical cleaning with sterile urethral catheters to prevent formation of biofilms on endotracheal tubes.
Methods: Forty-five children were randomized in equal numbers to endotracheal tube cleaning group for three times a day (group A), twice daily (group B), or to a control group with no endotracheal tube cleaning (group C). Bacterial studies and confocal laser scanning microscopy were performed to assess bacterial colonization and biofilm thickness on the internal surface of the endotracheal tube.
Results: In group B, the quantities of viable bacteria adhering to the endotracheal tube after 1 day of ventilation were similar to the control group but were significantly less by 3 days (p < 0.05). The quantities of viable bacteria adhering to the endotracheal tube in group A were significantly lower than group C from day 1 to day 7 (p < 0.05). The numbers of culture-positive endotracheal tube and lower respiratory tract secretions were both reduced in groups A and B compared with group C. Confocal laser scanning microscopy showed progressive development of mature biofilms in group C. Scattered bacteria were seen in group A with no biofilm formation. In group B, a small amount of extracellular polymeric substance was seen, with more bacterial cells than in group A. The biofilms in group B were significantly thinner than those in group C (p < 0.05). The occurrence of ventilator-associated pneumonia was significantly reduced by endotracheal tube cleaning.
Conclusion: Mechanical cleaning with sterile urethral catheters reduced bacterial colonization, prevented formation of endotracheal tube biofilm, and reduced the occurrence of ventilator-associated pneumonia.