Continuous Versus Intermittent Subglottic Secretion Drainage to Prevent Ventilator-Associated Pneumonia: A Systematic Review.

Background: Ventilator-associated pneumonia is associated with high morbidity and mortality in patients receiving mechanical ventilation. Subglottic secretion drainage, which may be performed continuously or intermittently, is believed to be an effective strategy for coping with ventilator-assisted pneumonia. Whether continuous or intermittent subglottic secretion drainage is superior for preventing ventilator-assisted pneumonia remains unknown.

Methods: This study is a comprehensive, systematic meta-analysis of randomized trials comparing continuous and intermittent subglottic secretion drainage in patients receiving mechanical ventilation. Studies in English and Chinese published from January 1970 through November 2015 were identified by searching multiple databases. Summary risk ratios or weighted mean differences with 95% CIs were used to calculate each outcome by means of fixed- or random-effects models.

Results: Eight studies enrolling a total of 1071 patients met the inclusion criteria. The summary risk ratio between continuous and intermittent subglottic secretion drainage for incidence of ventilator-assisted pneumonia was 0.83 (95% CI, 0.61-1.13); for time to ventilator-assisted pneumonia occurrence, 2.73 (95% CI, -0.39 to 5.85); for occult blood, 2.34 (95% CI, 0.25-21.88); for duration of mechanical ventilation, -0.89 (95% CI, -2.72 to 0.94); for length of intensive care unit stay, 3.98 (95% CI, -4.44 to 12.41); and for mortality, 0.80 (95% CI, 0.48-1.31).

Conclusions: The results indicate no apparent differences between continuous and intermittent subglottic secretion drainage for the treatment outcomes included in the analysis. Rigorously designed, large-scale randomized controlled trials are warranted to identify the roles of continuous and intermittent subglottic secretion drainage.