Efficacy of airway pressure release ventilation for acute respiratory distress syndrome: a systematic review with meta-analysis

Background: For many years, airway pressure release ventilation (APRV) has been used to manage patients with lung conditions such as acute respiratory distress syndrome (ARDS). However, it is still unclear whether APRV improves outcomes in critically ill ARDS patients who have been admitted to an intensive care unit (ICU). Methods: In this study, randomized controlled trials (RCTs) were used to compare the efficacy of APRV to traditional modes of mechanical ventilation. RCTs were sourced from PubMed, Cochrane, and Embase databases (the last dates from August 8, 2019). The Cochrane Handbook for Systematic Reviews of Interventions was used to assess the risk of bias. The relative risk (RR), mean difference (MD), and 95% confidence intervals (CI) were then determined. Article types such as observational studies, case reports, animal studies, etc., were excluded from our meta-analysis. In total, the data of 6 RCTs and 360 ARDS patients were examined. Results: Six studies with 360 patients were included, our meta-analysis showed that the mean arterial pressure (MAP) in the APRV group was higher than that in the traditional mechanical ventilation group (MD =2.35, 95% CI: 1.05-3.64, P=0.0004). The peak pressure (Ppeak) was also lower in the APRV group with a statistical difference noted (MD =-2.04, 95% CI: -3.33 to -0.75, P=0.002). Despite this, no significant beneficial effect on the oxygen index (PaO2/FiO(2)) was shown between the two groups (MD =26.24, 95% CI: -26.50 to 78.97, P=0.33). Compared with conventional mechanical ventilation, APRV significantly improved 28-day mortality (RR=0.66, 95% CI: 0.47-0.94, P=0.02). Discussion: All the included studies were considered to have an unclear risk of bias. We determined that for critically ill patients with ARDS, the application of APRV is associated with an increase in MAP. Inversely, a reduction of the airway Ppeak and 28-day mortality was recorded. There was no sufficient evidence to support the idea that APRV is superior to conventional mechanical ventilation in improving PaO2/FiO(2).