ABSTRACT
Introduction: High flow nasal cannula (HFNC) treatment is an efficient treatment for hypoxemia in acute respiratory distress syndrome (ARDS). Before the COVID pandemic, non-invasive ventilation was associated with higher mortality in ARDS, and early intubation was advocated. We hypothesized that HFNC treatment was more restrictive in the first wave of the COVID pandemic compared to the second wave respecting the pre-COVID conceptual consensus of early intubation in ARDS. Method(s): We conducted this retrospective observational singlecenter study in a tertiary ICU in Brussels during the COVID pandemic. The first flare-up ranged from March to May 2020, and the second flare-up from September to January 2021. All patients with COVID pneumonia and HFNC before intubation were included. We considered a delayed intubation a ROXi < 3.85 at the start of HFNC. ROXi is the ratio of SpO2/ FiO2 to the respiratory rate. The primary outcome was delayed intubation based on the ROXi in the number of days. The secondary outcome was mortality. Result(s): We included 60 patients in the first wave and 70 in the second wave. The duration of HFNC treatment before intubation was longer during the second wave, based on ROXi < 3.85: 1.6 days versus 2.8 days, p < 0.05 (Fig. 1). There was no significant difference in mortality, 18% versus 29%. The length of intubation was similar in both groups. The CCI, SOFA, APACHE III and SAPS II scores were similar in both groups. Conclusion(s): The duration of HFNC treatment in COVID-19-related ARDS before intubation has significantly been extended in the second pandemic wave. The delayed intubation based on the ROXi was in this study without significantly increased mortality. However, a trend toward higher mortality after prolonged HFNC was seen in the second pandemic wave.