The influence of high positive end-expiratory pressure ventilation combined with low tidal volume on prognosis of patients with acute lung injury/acute respiratory distress syndrome: a Meta-analysis

Abstract

To compare the effects of high and low positive end-expiratory pressure (PEEP) levels on prognosis of patients with acute lung injury/acute respiratory distress syndrome (ALI/ARDS). The data in PubMed, EMbase, Cochrane Library, CBM and CNKI were retrieved. All randomized controlled trials (RCTs) of treatment of ALI/ARDS with PEEP with high or low level were included. Study selection and assessment, data collection and analyses were undertaken by two independent reviewers. Meta-analyses were done using Cochrane Collaboration's RevMan 5.0 software. Six RCTs, involving a total of 2 484 patients of ALI/ARDS were included in the review. According to ventilation strategy, all trials were divided into subgroup A (high PEEP+low tidal volume of 6 ml/kg vs. low PEEP+low tidal volume) and subgroup B (high PEEP+low tidal volume vs. low PEEP+traditional tidal volume). In subgroup B, there were three RCTs, and high PEEP was found to be associated with a lower 28-day mortality [odds ratio (OR)=0.40, 95% confidence interval (95%CI) 0.22-0.72, P=0.003] and a lower barotraumas (OR=0.20, 95%CI 0.05-0.82, P=0.02) in patients with ALI/ARDS. In subgroup A, there were three RCTs, and it was found that the differences in 28-day mortality (OR=0.86, 95%CI 0.72-1.02, P=0.08) and barotraumas (OR=1.19, 95%CI 0.89-1.58, P=0.25) were not significant . As compared with conventional ventilation, high PEEP and low tidal volume ventilation are associated with improved survival and a lower rate of barotrauma in patients with ALI/ARDS. It is necessary to further confirm the role of high PEEP only in the ventilation strategy in patients with ALI/ARDS.