Background: Subglottic secretion drainage (SSD) has been shown to be associated with a lower incidence of ventilator-associated pneumonia (VAP) in a previous meta-analysis. However, a number of randomized controlled trials (RCTs) have been published since then, and so we aimed to conduct an updated meta-analysis.
Methods: A systematic literature search of Pubmed, Embase, and Cochrane Central Register of Controlled Trials was conducted using specific search terms. Eligible studies were RCTs that compared SSD with standard endotracheal tube care in mechanically ventilated adult patients.
Results: Ten RCTs with 2,213 patients were identified. SSD significantly reduced incidence of VAP (relative risk [RR] = 0.56, 95% confidence interval [CI]: 0.45-0.69, p < 0.00001) and early-onset VAP (RR = 0.23, 95% CI: 0.13-0.43, p < 0.00001), shortened ventilation duration by 1.55 days (95% CI: -2.40 to -0.71 days, p = 0.0003), and prolonged time to VAP by 3.90 days (95% CI: 2.56-5.24 days). Subgroup analyses suggested a significant reduction in incidence of VAP when stratified by intermittent (RR = 0.49, 95% CI: 0.34-0.71, p = 0.0001) and continuous SSD (RR = 0.61, 95% CI: 0.46-0.79, p = 0.0003). No significant differences were observed regarding incidence of late-onset VAP, overall mortality, or length of intensive care unit or hospital stay.
Conclusions: This updated meta-analysis confirmed that SSD was beneficial in preventing VAP. Furthermore, the effect of SSD on late-onset VAP, comparison between intermittent and continuous SSD, and safety of SSD in mechanically ventilated patients should be evaluated in future RCTs.
Level of evidence: I, meta-analysis.