How to treat patients with acute respiratory failure? Conventional oxygen therapy versus high-flow nasal cannula in the emergency department

Objective: To investigate whether high-flow nasal cannula oxygen therapy could reduce the rate of endotracheal intubation and improve arterial blood gas values, vital signs, and clinical outcomes of patients with hypoxemic acute respiratory failure as compared with conventional oxygen therapy alone. Methods: This retrospective, observational study was performed in the 15-month study period and included adult patients with tachypnea and hypoxemia, whose vital signs and arterial blood gas were monitored. The high-flow nasal cannula oxygen group consisted of patients admitted to the emergency department with acute respiratory failure when high-flow nasal cannula oxygen treatment was available in the hospital, while the conventional oxygen therapy group consisted of patients who have presented to the emergency department with acute respiratory failure in the absence of high-flow nasal cannula oxygen device in the hospital. The primary outcome of the study was improvement in vital signs and arterial blood gas values within first and fourth hours of the treatment. The second outcome was the need for intubation in the emergency department, length of hospital stay, and hospital mortality. Results: The decrease in the pulse and respiratory rate of high-flow nasal cannula oxygen-treated group was significantly greater than the conventional oxygen therapy group on the first and fourth hours of treatment (p < 0.001). PaO2 values were significantly higher in the high-flow nasal cannula oxygen group at the first and fourth hours of treatment (p <= 0.001). Likewise, mean SaO(2) levels of patients receiving high-flow nasal cannula oxygen treatment was significantly higher than those of patients in the conventional oxygen therapy group (p = 0.006 at 1 h and p < 0.001 at 4 h). In the hypercapnic patients, the decrease in PaCO2 and increase in pH and PaO2 values were significantly greater in high-flow nasal cannula oxygen group (p < 0.001). The difference between the groups regarding the need for invasive mechanical ventilation was not statistically significant (p = 0.179). Conclusion: High-flow nasal cannula oxygen treatment has been associated with favorable effects in vital signs and arterial blood gas values in patients with acute respiratory failure. High-flow nasal cannula oxygen might be considered as the first-line therapy for patients with hypoxemic and/or hypercapnic acute respiratory failure.