Figure 1.
Summary of studies identified for review
85 studies (two multicentre RCTs, 22 prospective observational studies, and 61 retrospective observational studies) were included in our review. BiPAP=bilevel positive airway pressure non-invasive ventilation. CPAP=continuous positive airway pressure non-invasive ventilation. HFNO=high-flow nasal oxygen. IMV=invasive mechanical ventilation. NIRS=non-invasive respiratory support. NR=not reported. RCT=randomised controlled trial. *RCT by Perkins et al95 included CPAP versus conventional oxygen therapy and HFNO versus conventional oxygen therapy, and therefore appears twice.