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

PURPOSE To assess the efficacy of subglottic secretion drainage in preventing ventilator-associated pneumonia. METHODS We performed a comprehensive, systematic meta-analysis of randomized trials that have compared subglottic secretion drainage with standard endotracheal tube care in mechanically ventilated patients. Studies were identified by a computerized database search, review of bibliographies, and expert consultation. Summary risk ratios or weighted mean differences with 95% confidence intervals were calculated for each outcome using a fixed-effects model. RESULTS Of 110 studies retrieved, five met the inclusion criteria and enrolled 896 patients. Subglottic secretion drainage reduced the incidence of ventilator-associated pneumonia by nearly half (risk ratio [RR] = 0.51; 95% confidence interval [CI]: 0.37 to 0.71), primarily by reducing early-onset pneumonia (pneumonia occurring within 5 to 7 days after intubation). Although significant heterogeneity was found for several endpoints, this was largely resolved by excluding a single outlying study. In the remaining four studies, which recruited patients expected to require >72 hours of mechanical ventilation, secretion drainage shortened the duration of mechanical ventilation by 2 days (95% CI: 1.7 to 2.3 days) and the length of stay in the intensive care unit by 3 days (95% CI: 2.1 to 3.9 days), and delayed the onset of pneumonia by 6.8 days (95% CI: 5.5 to 8.1 days). CONCLUSION Subglottic secretion drainage appears effective in preventing early-onset ventilator-associated pneumonia among patients expected to require >72 hours of mechanical ventilation.