The high incidence of COVID-19, the progressive nature of SARS-CoV-2 infection which can cause acute respiratory distress syndrome that affects the outcome of the disease, there is no effective management guide for COVID-19 especially for oxygenation therapy, and there is still controversy about use of high flow nasal cannula in COVID-19 patients. Methods: This study is an observational analytic study with a retrospective cohort study design to assess the ROX index on the success of using a high flow nasal canule (HFNC) in COVID-19 patients treated at H Adam Malik Hospital Medan based on data from medical records of 70 people. This research was conducted in October-November 2021 at RSUP H Adam Malik Medan using data from April 2020-April 2021. Results: In this study, the characteristics of the sample in this study had a mean age of 47 years. Based on gender, 35 men were found to be the most and based on comorbidities found in the most samples were DM and hypertension, 9 people with a length of stay of 6 days. In this study, the ROX index before the installation of HFNC obtained an average of 3.12 and after the installation of HFNC there was an increase in the average ROX index of 4.48. In this study, the successful installation of HFNC was 61 people out of a total of 70 samples. Discussion: The ROX index can be helpful in identifying subjects who are more at risk for poorer outcomes. Therefore, early invasive mechanical ventilation can be used to prevent worse outcomes in patients with COVID19-associated AHRF.

Keywords : ROX index, high flow nasal canule, NIV, ventilator, COVID-19