High-flow nasal cannula oxygen therapy in acute respiratory failure at Emergency Departments: A systematic review.

OBJECTIVES: The use of high-flow oxygen therapy (HFOT) through nasal cannula for the management of acute respiratory failure at the emergency department (ED) has been only sparsely studied. We conducted a systematic review of randomized-controlled and quasi-experimental studies comparing the early use of HFOT versus conventional oxygen therapy (COT) in patients with acute respiratory failure admitted to EDs. METHODS: A systematic research of literature was carried out for all published control trials comparing HFOT with COT in adult patients admitted in EDs. Eligible data were extracted from Medline, Embase, Pascal, Web of Science and the Cochrane database. The primary outcome was the need for mechanical ventilation, i.e. intubation or non-invasive ventilation as rescue therapy. Secondary outcomes included respiratory rate, dyspnea level, ED length of stay, intubation and mortality. RESULTS: Out of 1829 studies screened, five studies including 673 patients were retained in the analysis (350 patients treated with HFOT and 323 treated with COT). The need for mechanical ventilation was similar in both treatments (RR = 0.75; 95% CI 0.41 to 1.35; P = 0.31; I2 = 16%). Respiratory rate was lower with HFOT (Mean difference (MD) = -3.14 breaths/min; 95% CI = -4.9 to -1.4; P < 0.001; I2 = 39%), whereas sensation of dyspnea did not differ. (MD = -1.04; 95% CI = -2.29 to -0.22; P = 0.08; I2 = 67%). ED length of stay and mortality were similar between groups. CONCLUSION: The early use of HFOT in patients admitted to an ED for acute respiratory failure did not reduce the need for mechanical ventilation as compared to COT. However, HFOT decreased respiratory rate. REGISTRATION: PROSPERO ID CRD42019125696.