[The effects and safety of closed versus open tracheal suction system: a meta analysis]

To evaluate the effects and safety of closed tracheal suction system(CTSS) versus open tracheal suction system (OTSS) for mechanically ventilated patients.

All randomized controlled trials (RCTs) comparing CTSS with OTSS for mechanically ventilated patients home and abroad were identified via manual and computer retrieval. All related data were extracted. Meta analysis was conducted using the statistical software RevMan 5.1 on the basis of strict quality evaluation with the methods recommended by the Cochrane Collaboration.

Fifty-one related papers were found and 12 RCTs involving 1205 patients in CTSS group and 1179 patients in OTSS group were included. The results of meta analysis showed that CTSS was associated with a significant reduction in the duration of mechanical ventilation (WMD = -0.73, 95%CI -1.07 - -0.40, P < 0.0001), but the incidence of ventilator associated pneumonia and microbial colonization, mortality and length of ICU stay exhibited no difference between the two groups (P > 0.05). However, compared with OTSS, CTSS reduced the incidence of arrhythmia (RR = 0.23, 95%CI 0.07 - 0.74, P = 0.01) and minimized the disturbance to heart rate (WMD = -1.97, 95%CI -3.03 - -0.91, P = 0.0003), mean arterial pressure (WMD = -2.01, 95%CI -3.02 - -1.01, P < 0.0001) and oxygen saturation (SpO2) (WMD = -1.00, 95%CI -1.14 - -0.86, P < 0.000 01).

Compared with OTSS, CTSS could reduce disturbance to respiratory and circulatory system by sputum suction and shorten the duration of mechanical ventilation. However, CTSS has no advantage in prevention of ventilator associated pneumonia or microbial colonization, nor does it shorten the length of ICU stay or improve the outcome of mechanically ventilated patients.