Airway pressure release ventilation during acute hypoxemic respiratory failure: a systematic review and meta-analysis of randomized controlled trials

Background Airway pressure release ventilation (APRV) has been considered a tempting mode of ventilation during acute respiratory failure within the concept of open lung ventilation. We performed a systematic review and meta-analysis to verify whether adult patients with hypoxemic respiratory failure have a higher number of ventilator-free days at day 28 when ventilated in APRV compared to conventional ventilation strategy. Secondary outcomes were difference in PaO 2 /FiO 2 at day 3, ICU length of stay (LOS), ICU and hospital mortality, mean arterial pressure (MAP), risk of barotrauma and level of sedation. We searched MEDLINE, Scopus and Cochrane Central Register of Controlled Trials database until December 2018. Results We considered five RCTs for the analysis enrolling a total of 330 patients. For ventilatory-free day at day 28, the overall mean difference (MD) between APRV and conventional ventilation was 6.04 days (95%CI 2.12, 9.96, p = 0.003; I 2 = 65%, p = 0.02). Patients treated with APRV had a lower ICU LOS than patients treated with conventional ventilation (MD 3.94 days [95%CI 1.44, 6.45, p = 0.002; I 2 = 37%, p = 0.19]) and a lower hospital mortality (RD 0.16 [95%CI 0.02, 0.29, p = 0.03; I 2 = 0, p = 0.5]). PaO 2 /FiO 2 at day 3 was not different between the two groups (MD 40.48 mmHg [95%CI − 25.78, 106.73, p = 0.23; I 2 = 92%, p