Better Outcomes for Ventilation With Lower Tidal Volumes
(HealthDay News) – Protective ventilation with lower tidal volumes is associated with better clinical outcomes in patients without acute respiratory distress syndrome (ARDS).
Ary Serpa Neto, MD, from ABC Medical School in São Paulo, Brazil, and colleagues conducted a literature review to identify studies in which lower versus higher tidal volumes were reported in patients receiving ventilation, but without ARDS, and which reported lung injury development, overall mortality, pulmonary infection, atelectasis, and biochemical alterations. Twenty articles with 2,822 participants were included in the review.
Using a fixed-effects model, the researchers found significant decreases in lung injury development (risk ratio [RR], 0.33; number needed to treat [NNT], 11), and mortality (RR, 0.64; NNT, 23) for patients receiving ventilation with lower tidal volumes. In protective ventilation groups, meta-analysis using a random-effects model showed a lower incidence of pulmonary infection (RR, 0.45; NNT, 26); lower mean hospital length of stay (6.91 vs. 8.87 days); higher mean PaCO2 levels (41.05 vs. 37.90mmHg); and lower mean pH values (7.37 vs. 7.40). The mean ratios of PaO2 to fraction of inspired oxygen (304.40 and 312.97, respectively) were similar for lower versus higher tidal volume.
"Our meta-analysis suggests that, among patients without lung injury, protective ventilation with use of lower tidal volumes at onset of mechanical ventilation may be associated with better clinical outcomes," the authors write.