[The characteristics of biofilm formation in endotracheal tubes in ventilated patients].

OBJECTIVE To evaluate the etiology and drug resistance of biofilms in endotracheal tubes in respiratory intensive care unit (RICU). METHODS A prospective cohort study was conducted. The biofilms were observed by scanning electron microscopy at different times of ventilation. The pathogens were identified and their resistance to antibiotics were analyzed. RESULTS Twenty one VAP cases were identified in 39 mechanically ventilated patients (53.85%). Patchy biofilms were observed 2 d to 7 d after the initiation of ventilation. After 7 d to 10 d, 87.5% of the endotracheal tubes were covered by biofilms. Biofilms were identified in all the tubes longer than 10 d. CONCLUSIONS The incidence of VAP increased with prolonged mechanical ventilation. Meanwhile the antibiotic resistance rate increased and more pathogens isolated were consistent with those in the biofilms.