Nasal high flow oxygen therapy compared to conventional oxygen therapy in hospitalised patients with respiratory illness: a systematic review and meta-analysis

Abstract

<b>Background:</b> Nasal high flow oxygen (NHFO) therapy has been increasingly adopted to treat respiratory illnesses, especially since the COVID-19 pandemic. <b>Aim:</b> This systematic review aimed to compare health outcomes of nasal high flow oxygen (NHFO) therapy versus conventional oxygen therapy (COT) in hospitalised adults with acute and chronic respiratory illnesses. <b>Methods:</b> A comprehensive search was performed across Medline, Embase, and CENTRAL databases in June 2021 for randomised controlled trials (RCTs), interventional, and observational studies that reported on at least one predefined outcome. <b>Results:</b> 54 studies (20 RCTs) of acute respiratory illnesses (ARI) and 14 studies (8 RCTs) of chronic respiratory illnesses (CRI) were included. In patients with ARI, compared to COT, NHFO did not reduce the overall need for invasive mechanical ventilation (IMV) escalation, risk ratio (RR)=0.85 [95%CI 0.72-1.01; p=0.06]. In patients with CRI, NHFO significantly reduced IMV escalation need, RR=0.66 [95%CI 0.46-0.93; p=0.02]. In COVID-19 patients, NHFO was associated with mortality benefits in the short-term, RR= 0.62 [95% CI 0.48-0.79; p=0.0001] and long-term, RR= 0.67 [95% CI 0.48-0.92; p=0.01]. Moreover, NHFO significantly reduced the need for IMV escalation in COVID-19 patients, RR= 0.72 [95% CI 0.63-0.82; p&lt;0.00001] and in patients with acute respiratory failure (ARF) from all-causes, RR= 0.82 [95% CI 0.71-0.96; p=0.01]. <b>Conclusions:</b> Compared to COT, NHFO significantly reduced the overall need for IMV escalation in patients with CRI, COVID-19, and ARF.