Airway Pressure Release Ventilation for Acute Respiratory Failure Due to Coronavirus Disease 2019: A Systematic Review and Meta-Analysis

Objective To explore the evidence surrounding the use of Airway Pressure Release Ventilation (APRV) in patients with coronavirus disease 2019 (COVID-19). Methods: A Systematic electronic search of PUBMED, EMBASE, and the WHO COVID-19 database. We also searched the grey literature via Google and preprint servers (medRxive and research square). Eligible studies included randomised controlled trials and observational studies comparing APRV to conventional mechanical ventilation (CMV) in adults with acute hypoxemic respiratory failure due to COVID-19 and reporting at least one of the following outcomes; in-hospital mortality, ventilator free days (VFDs), ICU length of stay (LOS), changes in gas exchange parameters, and barotrauma. Two authors independently screened and selected articles for inclusion and extracted data in a pre-specified form. Results: Of 181 articles screened, seven studies (one randomised controlled trial, two cohort studies, and four before-after studies) were included comprising 354 patients. APRV was initiated at a mean of 1.2-13 days after intubation. APRV wasn't associated with improved mortality compared to CMV (relative risk [RR], 1.20; 95% CI 0.70-2.05; I-2, 61%) neither better VFDs (ratio of means [RoM], 0.80; 95% CI, 0.52-1.24; I-2, 0%) nor ICU LOS (RoM, 1.10; 95% CI, 0.79-1.51; I-2, 57%). Compared to CMV, APRV was associated with a 33% increase in PaO2/FiO(2) ratio (RoM, 1.33; 95% CI, 1.21-1.48; I-2, 29%) and a 9% decrease in PaCO2 (RoM, 1.09; 95% CI, 1.02-1.15; I-2, 0%). There was no significant increased risk of barotrauma compared to CMV (RR, 1.55; 95% CI, 0.60-4.00; I-2, 0%). Conclusions: In adult patients with COVID-19 requiring mechanical ventilation, APRV is associated with improved gas exchange but not mortality nor VFDs when compared with CMV. The results were limited by high uncertainty given the low quality of the available studies and limited number of patients. Adequately powered and well-designed clinical trials to define the role of APRV in COVID-19 patients are still needed. Registration: PROSPERO; CRD42021291234.