Non-Invasive Ventilation in the Prehospital Emergency Setting: A Systematic Review and Meta-Analysis

Introduction Noninvasive ventilation is a well-established treatment for acute respiratory failure, being increasingly applied in the prehospital setting. This systematic review and meta-analysis aims to investigate whether early prehospital initiation of noninvasive ventilation reduces mortality compared to standard oxygen therapy. Methods We searched PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials from inception to February 7(th), 2022, for studies comparing prehospital noninvasive ventilation performed by emergency medical services versus standard oxygen therapy in patients with acute respiratory failure. The primary outcome was mortality at the longest follow-up available. Results We included ten randomized studies and two quasi-randomized studies for a total of 1485 patients. Prehospital treatment with noninvasive ventilation compared with standard oxygen therapy did not significantly reduce mortality at the longest follow-up available (107/810 [13%] vs 114/772 [15%]; RR = 0.89; 95% CI, 0.70-1.13; P = 0.34; I-2=24%). The endotracheal intubation rate was reduced when receiving prehospital noninvasive ventilation (38/776 [4.9%] vs 81/743 [11%]; RR = 0.44; 95% CI, 0.31-0.63; P < 0.001; I-2=0%; number needed to treat 17). The intensive care admission rate (114/532 [21%] vs 129/507 [25%]; RR = 0.85; 95% CI, 0.69-1.04; P = 0.11; I-2=0%) and length of hospital stay (mean difference=-1.29 days; 95% CI, -3.35-0.77; P = 0.21; I-2=82%) were similar between groups. Conclusions Adults with acute respiratory failure treated in the prehospital setting with noninvasive ventilation had a lower risk of intubation than those managed with standard oxygen therapy, with similar risk of death, intensive care admission, and length of hospital stay. Review registration PROSPERO CRD42021284947