Sequential Application of Oxygen Therapy Via High-flow Nasal Cannula and Non-invasive Ventilation in COVID-19 Patients with Acute Respiratory Failure in the Intensive Care Unit: A Prospective, Observational Study

Objective:Non-invasive mechanical ventilation (NIV) and high-flow nasal oxygen therapy (HFNO) are the most frequently used methods for treating hypoxemia in those diagnosed with coronavirus disease-2019 (COVID-19) in the intensive care unit (ICU). In this prospective study, we compared the effects of these two treatment modalities applied alternately in the same patient.Materials and Methods:Standard oxygen therapy (SOT) was administered for 1 hour to patients hospitalized in the ICU with a diagnosis of acute hypoxemic respiratory failure (AHRF) and acute respiratory distress syndrome (ARDS) due to COVID-19. HFNO and NIV were applied alternately to patients who met the inclusion criteria, and we evaluated the effects of HFNO and NIV applied to the same patient.Results:Thirty of forty-five patients admitted to the ICU for COVID-19 ARDS met the inclusion criteria for the study. According to the first and second arterial blood gas (ABG) values, the PaO2/FiO2 (P/F) ratio was significantly higher during NIV compared to both baseline and HFNO. In addition, the ROX index was significantly higher during NIV than HFNO, and SpO2 in NIV increased significantly compared with the baseline value. In both methods, patient satisfaction according to the visual analog scale was better than that of SOT. Eighty percent (24/30) of the patients were orotracheally intubated; 13 patients were transferred to the ward (43.3%), 2 patients were discharged home (6.7%), and 15 patients died (50%).Conclusion:Starting respiratory support with HFNO and/or NIV rather than SOT is more effective in improving oxygenation in patients with AHRF and ARDS due to COVID-19 and other causes. NIV is more effective than HFNO in increasing the SpO2 and P/F ratio.