Airway colonisation in long-term mechanically ventilated patients - Effect of semi-recumbent position and continuous subglottic suctioning

Objective. To evaluate the impact of continuous subglottic suctioning and semi-recumbent body position on bacterial colonisation of the lower respiratory tract. Design. A randomised controlled trial. Setting. The ten-bed medical ICU of a French university hospital. Patients. Critically ill patients expected to require mechanical ventilation for more than 5 days. Interventions. Patients were randomly assigned to receive either continuous suctioning of subglottic secretions and semi-recumbent body position or to receive standard care and supine position. Measurements and results. Oropharyngeal and tracheal secretions were sampled daily and quantitatively cultured. All included patients were followed up from day 1 (intubation) to day 10, extubation or death. Ninety-seven samples of oropharynx and trachea were analysed (40 for the suctioning group and 57 for the control group). The median bacterial counts in trachea were 6.6 Log(10) CFU/ml (interquartile range, IQR, 4.4-8.3) in patients who received continuous suctioning and 5.1 Log(10) CFU/ml (IQR 3.6-5.5) in control patients. Most of the patients were colonised in the trachea after 1 day of mechanical ventilation (75% in the suctioning group, 80% in the control group). No significant difference was found in the daily bacterial counts in the oropharynx and in the trachea between the two groups of patients. Conclusion. Tracheal colonisation in long-term mechanically ventilated ICU patients was not modified by the use of continuous subglottic suctioning and semi-recumbent body position.