Subglottic secretion drainage for preventing ventilator associated pneumonia : a meta-analysis

Background: Ventilator associated pneumonia (VAP) in the intensive care unit (ICU) has been shown to be associated with significant morbidity and mortality. It has been reported to affect between 9 and 27% of intubated patients receiving mechanical ventilation. Objective: A meta-analysis was undertaken to combine information from published studies of the effect of subglottic drainage of secretions on the incidence of ventilated associated pneumonia in adult ICU patients. Data sources: Studies were identified by searching MEDLINE (1966 to January 2011), EMBASE (1980-2011), and CINAHL (1982 to January 2011). Review methods: Randomized trials of subglottic drainage of secretions compared to usual care in adult mechanically ventilated ICU patients were included in the meta-analysis. Results: Subglottic drainage of secretions was estimated to reduced the risk of VAP by 48% (fixed-effect relative risk (RR)=0.52, 95% confidence interval (CI), 0.42-0.65). When comparing subglottic drainage and control groups, the summary relative risk for ICU mortality was 1.05 (95% CI, 0.86-1.28) and for hospital mortality was 0.96 (95% CI, 0.81-1.12). Overall subglottic drainage effect on days of mechanical ventilation was -1.04 days (95% CI, -2.79-0.71). Conclusion: This meta-analysis of published randomized control trials shows that almost one-half of cases of VAP may be prevented with the use of specialized endotracheal tubes designed to drain subglottic secretions. Time on mechanical ventilation may be reduced and time to development of VAP may be increased, but no reduction in ICU or hospital mortality has been observed in published trials