Although the COVID-19 pandemic has ended, severe cases of COVID-19 pneumonia (pneumonia caused by SARS-CoV-2) are still common in clinical practice. These patients frequently suffer from hypoxemia, for which conventional oxygen therapy (COT) may be insufficient. High-flow nasal oxygen (HFNO) provides enhanced oxygen delivery, but its overall clinical benefits remain uncertain. Our meta-analysis assesses HFNO's effectiveness and safety compared to COT for treating COVID-19-related hypoxemia by combining data from RCTs.

We thoroughly explored six databases to identify suitable RCTs that examined HFNO versus COT in COVID-19 hypoxemic patients. Mortality and intubation were the main outcomes, while secondary outcomes included hospitalization indicators and blood gas monitoring indicators following oxygen therapy.

Eight RCTs involving 2528 patients were included. HFNO therapy demonstrated significantly lower rates of total intubation (Risk ratio: 0.86 [0.78, 0.95], P = 0.003), as well as intubation at 7, 14, and 28 days compared with COT. Additionally, the HFNO group showed a shorter time to oxygen therapy de-escalation (MD: 3.53 [-4.50, −2.55] days, P < 0.00001). After oxygenation therapy, the HFNO group exhibited a lower respiratory rate (MD: 2.77 [-3.67, −1.88] breaths/min, P <  0.00001), PaCO ₂ (MD: 1.00 [-1.67, −0.33] mmHg, P = 0.003), and a higher SpO ₂ /FiO ₂ ratio (MD: 47.00 [34.77, 59.23], P  <  0.00001). Similar baseline characteristics and mortality rates were found between the two groups.

HFNO treatment demonstrated advantages over COT, with comparable mortality rates, reduced intubation requirements, and improved post-therapy monitoring metrics in patients with COVID-19-induced hypoxemia.