[A meta-analysis of low tidal volume on the outcome of adult patients without acute respiratory distress syndrome].

Objective: To evaluate the effects of tidal volume on the survival in adult patients without acute respiratory distress syndrome (non-ARDS). Methods: We searched relevant clinical randomized controlled trials (RCT) from January 2000 to December 2015. Meta analyses related to the effects of tidal volume on mortality in non-ARDS adults were conducted using the methods recommended by the Cochrane Collaboration. Results: A total of nineteen RCTs ( n =1 679) were finally included. There were 838 patients ventilated with low tidal volume, and the other 841 patients ventilated with normal tidal volume. The mortality rates were not significantly different between low tidal volume group and control group (5.87% vs 6.52%; RR =0.9, P =0.58). But respiratory complications were significantly lower in low tidal volume group, such as development of acute respiratory distress syndrome( RR =0.32, 95% CI 0.16-0.63, P =0.001), pneumonia ( RR =0.48, 95% CI 0.29-0.78, P =0.003), while the incidence of atelectasis was quite comparable between two groups ( RR =0.78, 95% CI 0.391-1.356, P =0.48). Conclusion: Non-ARDS patients ventilated with low tidal volume is associated with a lower risk of pulmonary complications, yet clinical outcome, mainly mortality is similar to that of patients with regular tidal volume.