The effect of prolonged intubation on ventilator associated pneumonia: endotracheal tube cuff is really steril or not?

Aims: Endotracheal tube (ETT) design, size, cuff material, cuff pressure, and intubation duration are critical in preventing nosocomial pneumonia. We aimed to evaluate the possible infection focus potential of ETT cuff and pilot balloon, particularly in prolonged intubated patients. Methods: A total number of 66 patients who underwent orotracheal intubation and received conventional mechanical ventilation more than 48 hours in the intensive care unit (ICU), were included in this prospective cohort study. Results:The mean duration of intubation was 10.36±4.82 days. Bacteriologically confirmed positive tracheal aspirate culture was 18.2% (n=12). The most frequent positive culture was detected inside of ETT lumen with a percentage of 83.3% (n=55) and followed by cuff (27.3%, n=18), pilot balloon (13.6%, n=9), respectively. It was documented that rates of lung infections were significantly increased after 14 days (p = 0.017) and rates of cuff positive cultures were significantly increased after 10 and 14 days of incubation (p= 0.001, p=0.004). The same type of bacteriological strains was identified from both pilot balloon (n=9) and ETT cuff (n=9), simultaneously. In the remaining 9-cuff positive patients pilot balloons were sterile and ETT lumens were positive culture with the same strains as identified from the cuff. There was a statistically significant positive correlation between the intubation duration and the number of infected ETT parts (p<0.001). Conclusion: ETT cuff was demonstrated to be a potential infection focus in the present study. In addition, it was observed that ETT cuff colonization increased in proportion to the intubation duration. We suggest changing ETT at appropriate time intervals in order to reduce ventilator-associated pneumonia in intubated patients.